Mitigation of drought stress in spinach using individual and combined applications of salicylic acid and potassium

Drought stress is a major constraint impairing crops growth around the globe. It not only decreases the growth of crops but also converted cultivatable land into barren non-cultivatable area. The salicylic acid (SA) and recommended potassium (K) application have the potential to alleviate the adverse effects of drought stress on crops. Current greenhouse pot experiment was conducted to investigate the influence of various levels of SA and K on spinach growth under drought stress. There were three levels of SA i.e., 0 micro Molar (µM), 300 µM and 600 µM and K i.e., control (0), half recommended dose (34.5 mg / 5 kg soil) and full recommended dose (69.0 mg / 5kg). Results showed that drought stress significantly decreased shoot and root, lengths and dry weights, chlorophyll a and b, total chlorophyll and nutrients uptake. It also significantly increased electrolyte leakage in spinach leaves. However, application of SA600 + FK significantly enhanced shoot (33.3%) and root lengths (44.5%), dry weights of plants (58.1%), chlorophyll a (72.7%), chlorophyll b (115.7%) and total chlorophyll content (88.4%) in spinach under drought. More spinach growth, under drought conditions, subjected to SA600 and FK was linked with better root elongation and nutrients (N, P and K) uptake. In conclusion, co-application of SA and K has more potential to improve spinach growth under drought stress compared to their sole applications. However, SA600 and FK are more effective levels compared to SA300 and HK for the alleviation of native effects of drought in spinach.

Effect of uniconazole treatment on the drought tolerance of soybean seedlings

Uniconazole is an important growth regulator in plants in response to abiotic stresses. However, the effects of uniconazole on the leaf physiology and growth of soybean seedlings under drought conditions remain unclear. Thus, this study investigated the effects of uniconazole on the photosynthetic characteristics, antioxidant activities, and morphological structure of soybean varieties Suinong14 (Glycine max var.) (drought sensitive) and Heinong64 (Glycine max var.) (drought tolerant) under drought conditions through pot experiments. Results showed that drought significantly decreased the growth of the plants. However, the drought-stressed plants with uniconazole treatment showed considerably higher biomass than the drought-stressed plants without uniconazole treatment. Uniconazole treatment showed better effects on Heinong64 than on Suinong14. The uniconazole-treated plants displayed longer roots and thicker stems than the untreated plants. Moreover, the drought-stressed plants with uniconazole treatment exhibited higher chlorophyll contents, photosynthetic rates, transpiration rates, and stomatal conductance but lower lipid peroxidation contents and relative electrical conductivity than the drought-stressed plants without uniconazole treatment. The content of foliar soluble sugar, the content of soluble protein, and the activities of superoxide dismutase, peroxidase, and catalase were increased by uniconazole treatment under drought and well-watered conditions. These results indicate that uniconazole can effectively alleviate the adverse effects of drought partly by modifying the morphology and physiology of the plants.

Comparative proteomics analysis reveals important drought responsive proteins in the leaves of a potato variety tolerant to drought stress

Drought stress inhibits the growth and productivity of potato. The mechanism of drought tolerance in potato remains largely unclear. Potato Dongnong 308, tolerant to drought stress, was selected to perform an identification of different abundance proteins using 2D-PAGE and LC-MS/MS accompanying with a physiological and ultrastructural observation to uncover its drought tolerant mechanism in potato leaves. Potato plants can adapt morphologically and physiologically to reduce the damage of drought stress to the plant cell. Under drought condition, the water content in potato leaves had a weak reduction and resulted in a significantly decreased root activity. The SOD activity and MDA content showed a significant increase, suggested that physiological changes occurred in potato leaves under drought stress. After inducing water deficitstress, some chloroplasts separated from cell wall and moved to cell center and grana lamella become netty with increased space between lamellas. In addition, a few chloroplasts became swelled, suggesting its function become weak. With the decreasing supply of energy from chloroplast, other energy supply metabolic pathways were active. Sixteen proteins were accumulated differentially and were involved in chloroplast structure and function, secondary metabolism activation, protein folding/processing and synthesis, glycolysis regulation, and stimulation of ATP synthesis. Their functions in potato leaves were mainly related to activate the process of metabolism adjustment and to mobilize the defense system under drought stress. The abundance of heat shock proteins (HSP) correlated with alleviating the accumulation of reactive oxygen species (ROS) against abiotic stresses, which should facilitate the increase of drought tolerance in potato. The identified physiological parameters and proteins provide new insight of the molecular mechanism to drought tolerance in potato.

Comparative study of growth, physiology and yield attributes of camelina (Camelina sativa L.) and canola (Brassica napus L.) under different irrigation regimes

Camelina (Camelina sativa L.) is an alternative oilseed crop having several attractive features making it a potential oilseed crop. To assess the physiology, growth and yield responses of different genotypes of camelina and canola crops under various irrigation regimes two field trials were conducted for consecutive growing seasons in 2013-14 and 2014-15. Randomized complete block design (RCBD with factorial arrangements was adopted. In this experiment two camelina genotypes (Camelina-611 and Camelina-618), and two canola genotypes (Punjab sarsoon and Faisal canola) were used with four levels of irrigations I₀ (two irrigations: 1^st at vegetative stage and 2^nd at reproductive stage), I₁ (one irrigation at vegetative stage), I₂ (one irrigation at reproductive stage), and I₃ (no irrigation). The results revealed that the maximum values of leaf gas exchange traits, chlorophyll and carotenoid content, leaf water relation, yield and yield components were noted when two irrigations (I₀) were applied and it was followed by one irrigation at vegetative stage (I₁). However, the minimum values of these traits were recorded in water deficit plants that received no irrigation (I₃). Among the genotypes Camelina-618 relatively performed well as compared to other genotypes regarding all the recorded parameters (leaf gas exchange, chlorophyll and carotenoid content, leaf water relation, yield and yield components) under both well-watered and water stressed conditions.

Genetic manifestation of physio-morphic and yield related traits conferring thermotolerance in wheat

High temperature threatens the sustainability of wheat productivity. Knowledge of gene action and combining ability of parents assist the breeders to develop heat resilient wheat cultivars. Therefore, present study was designed to ascertain the combining ability of parents, nature of gene action and heritability under delayed planting mediated heat stress. Initially five heat tolerant genotypes were selected form 158 wheat genotypes on the basis of least cell membrane injury, high rate of photosynthesis, proline content, transpiration rate and cooler canopy temperature at seedling stage. Heat tolerant genotypes as male parents were crossed with ten high yielding genotypes as female parents following line × tester mating design. Fifty F₁ hybrids along with 15 parents were evaluated under normal and heat stress for physio-morphic traits. Results revealed that all traits except stay green, plant height, leaf area, spike length and tillers per plant were controlled by additive genetic effects under both normal and heat stress conditions. High narrow sense heritability was noticed for canopy temperature depression at reproductive stage (65%), transpiration rate at seedling stage (73%), photosynthetic rate at seedling and reproductive (83%, 73%), proline content at seedling and reproductive (64%, 62%). High heritability with additive genetic effects suggested the utilization of these traits with modified pedigree selection for developing thermotolerant varieties

Assessment of secondary metabolism involvement in water stress tolerance of quinoa (Chenopodium quinoa Willd.) subjected to varying water regimes

Water deficiency is a most prevalent problem which directly affects the plant growth and yield production. Keeping in view, the present study was conducted to examined the stress resistant potential of quinoa (Chenopodium quinoa Willd.) subjected to varying water regimes [100%, 60%, 40% and 20% field capacity (F.C.)]. Four different cultivars (V1, V2, V7 and V9) of quinoa were allowed to grow for two weeks after seed germination under normal conditions. After it, seedlings of quinoa were subjected to different levels of water stress. The required drought stress levels were maintained after 30 days of seed germination. After fifteen days of drought stress treatments, the data were collected for growth and various physio-biochemical attributes. Drought stress considerably reduced the plant growth in terms of shoot and root fresh as well as dry weights alongwith chlorophyll a and b contents and relative water contents (RWC) while a considerable increase was observed in hydrogen peroxide (H₂O₂), malondialdehyde (MDA), proline and total sugar contents in all four quinoa cultivars. Overall, it can be suggested that of all four quinoa cultivars, cv. V9 has the ability to cope with severe drought stress so it is considered as more drought tolerant and cv. V7 considered as drought sensitive particularly on the basis of plant growth.

Agro-morphological assessment and seed protein profiling in carrot (Daucus carota L.) germplasm

Carrot (Daucus carota L.) is an important vegetable, and one of the main sources of dietary pro-vitamin A carotenoids. Carrot accessions were investigated for genetic diversity using qualitative and quantitative morphological traits and biochemical analysis at National Agricultural Research Centre (NARC), Islamabad, Pakistan. A set of 33 carrot accessions were subjected to agro-morphological evaluation which revealed that said genotypes have great variation for yield contributing traits (root’s weight, length and width) and various quality attributes i.e., root shape and color. Relationship among various traits based on correlation analysis showed some key facts with significant (p≤0.05 and p≤0.01) negative and positive correlation indicating the utility of the existing carrot germplasm. Cluster analysis divided and placed the accessions in five clusters, showing variations among accessions collected from geo-climatically diverse localities of Pakistan. Multivariate analysis enunciated a deep insight to understand variability pattern and relationship among carrot germplasm acquired from diverse ecologies of Pakistan. However, low variability with monomorphic banding was observed based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Distinct root trait needs to be identified and further evaluation should be carried out on diverse genetic base on the basis of agro-morphological traits. Carrot accession 20238 from Khanewal area was found to be the most distinct accession as reflected by multivariate analysis. The promising genotypes could be used for the development of high yielding genotypes in future breeding program.

Regulation of morpho-physiological and vase quality attributes of carnation (Dianthus caryophyllus) cv. tabasco mediated by GA₃

Gibberellic acid (GA₃) is an excellent plant growth regulator and a promoter of vase life that accelerates the antioxidant activities in the plants. In the present study, GA₃ was tested for its hypothesized influences on growth and vase life attributes of carnation plant. Plants were treated with triple-frequency six levels of GA₃, i.e., controls, 25, 50, 100, 200 and 400 mg/L initiated one month post-transplantation. The results helped to infer several floral traits following GA₃ treatment. Early flower initiation, flower diameter, stalk length, stalk diameter, flower yield per plant and maximum fresh and dry weight of cut flowers were grossly improved with highest concentration of GA₃. The variance in the improved traits of plant parameters was explained by the increasing concentrations of GA₃ foliar spray. The parameters enormously influenced by GA₃ treatments were the percentage of flower opening and the vase life of cut flowers, which were likely attributable to the reduced ethylene synthesis and improved membrane integrity of petals. The activities of antioxidants varied between 25 mg/L and 400 mg/L GA₃ treatments versus control. The study provided a sound insight into the favourable effects of GA₃ applications on overall growth and antioxidant activities of carnation cut flowers which prolonged their vase life.

Growth, protein expression and heavy metal uptake by tobacco under heavy metals contaminated soil

This paper investigates heavy metal uptake, growth and protein expression of two tobacco cultivars (Flue cured Virginia, Dark sun cured) when exposed to heavy metals (Cd, Cr and Pb) and EDTA. Statistically analysis of the data revealed that growth parameters and heavy metal accumulation were significantly (p<0.05) affected by heavy metal and EDTA application. Minimum leaf fresh weight, dry weight and shoot length was measured by the application of Cr (500 mg kg^-1) as compared to other heavy metals and controls. Maximum reduction in leaf fresh weight, dry weight and shoot length was noted with the exposure of tobacco plants to 5 mM EDTA compared with control (0 mM EDTA). Heavy metals uptake was more by Flue cured Virginia than Dark sun cured. Tobacco cultivars exposed to heavy metal and EDTA resulted in the expression of several proteins of different molecular weight.

Genome-wide identification and analysis of maize PAL gene family and its expression profile in response to high-temperature stress

Phenylalanine ammonia-lyase (PAL) plays a crucial role in the process of plant growth and stress response by catalyzing L-phenylalanine deamination. Maize (Zea mays L.) B73 genome, mRNA and amino acid databases were used here to assess the functional characteristics and expression patterns of the PAL gene family. Through genome-wide bioinformatics analysis, 13 members of the PAL family were identified, and predictive analysis were carried out considering the chromosomal locations, differentiation profiles, physicochemical properties and secondary structures of their encoded proteins, as well as their structures, conserved motifs, phylogenesis and expression patterns. The results revealed the 13 maize PAL (ZmPAL) genes that were unevenly distributed on 10 chromosomes and that their differentiation was achieved through tandem and fragment duplication, occurring approximately 6.16-36.09 million years ago. Most ZmPAL proteins are acidic proteins, with secondary structures mainly composed of α-helices. Structure and motif analyses revealed high conservation in the intron number in ZmPAL genes and in the overall amino acid sequences. Phylogenetic trees exhibited a clear division into six subfamilies, with the largest number of orthologues in maize, sorghum and rice, and a close genetic relationship among them. In addition, the expression levels of the ZmPAL genes were different in various tissues under high-temperature, indicating responsiveness to this stress factor. Furthermore, a synchronous increase in the total phenolics and total flavonoids contents was observed in parallel to the increase in PAL activity under high temperature stress. This outcome indicated that the PAL genes can respond to high-temperature stress by promoting the synthesis of total phenolics and flavonoids. These results will facilitate future research on the biological functions of PAL genes and its exploitation in the production of high-temperature resistant cultivars

Cadmium decreased superoxide anion derived from NADPH oxidase through overload of calcium in wheat seedling

Cadmium (Cd) pollution is an important environmental problem in society. Cd is released by industrial processes and phosphate fertilizers, permeates into the food chain. It inhibits plant growth and changes photosynthesis, and its pytotoxicity damages the plant. Over-production of reactive oxygen species (ROS) is believed to be one of the key factors responsible for Cd toxicity. Our objective was to clarify the roles of ROS and cytoplasm free calcium ([Ca²⁺]_cyt) in wheat seedlings containing cadmium (Cd). Wheat grains were treated by a series of doses of cadmium chloride for six days. Results showed that wheat grains germination and seedling growth inhibition were increased with increasing Cd concentration. Additionally, low Cd concentration (0.05 mM) decreased NADPH oxidase (NOX) activity, and superoxide anion (O₂^·-) and malondialdehyde (MDA) contents. Conversely, [Ca²⁺]_cyt was significantly increased at 0.05 mM Cd. To obtain deeper insights into the redox balance of wheat seedling response to Cd stress, O₂^·-, H₂O₂ and MDA content In vivo were measured. The results showed that exogenous O₂^·markedly promoted seedling growth, increased O₂^·- content and NOX activity, and impaired [Ca²⁺]_cyt overload by Cd stress. Therefore, it was concluded that Cd inhibited early growth of seedlings mainly through inducing [Ca²⁺]_cyt overload which was attributed to the decrease of NOX-dependent O₂^·- production.

Molecular detection and characterisation of phytoplasma in Trigonella foenum-graecum and identification of potential insect vectors in Punjab, Pakistan

Discerning with crop health issues, this study was conducted to detect and identify phytoplasmas and their potential insect vectors in symptomatic Fenugreek (Trigonella foenum-graecum) plants collected from Punjab, Pakistan. The detection of phytoplasma in collected leafhopper species and Fenugreek plants was confirmed by nested PCR amplification of 16SrDNA by employing primer pairs (P1/P7 & R16F2n/R16R2). Our results indicated that all the symptomatic fenugreek plant and specimens of leafhoppers, Orosius albicinctus, Empoasca spp., and Balclutha incisa resulted positive in PCR. Sequencing of amplified DNA products and phylogenetic analysis of our Fenugreek phyllody phytoplasma (Accession number MH398586) showed that the phytoplasma strains detected has maximum identity (100%) with ‘Candidatus Phytoplasma australasiae’ subgroup 16Sr-II-D (Gen Bank number Y10097. This is the first detection and identification of phytoplasma presence in fenugreek seed plants with putative potential insect vectors in Faisalabad, Punjab, Pakistan

Salinity induced variability in morpho-physiological traits and their relationship with grain yield in rice (Oryza sativa L.)

Salinity is one of the most important abiotic constraint causes significant yield losses in rice crop specially when occur at flowering stage. The losses are mainly due to excessive accumulation of toxic ions mainly sodium in shoot affecting physiological processes osmotically and ionically. Twelve rice genotypes were studied under hydroponically controlled saline conditions (50 mM NaCl) along with non-saline control. Variability of sodium in shoot was assessed at vegetative, flowering and maturity stages and the impact of sodium accumulation on physiological traits of chlorophyll, proline, potassium sodium ratios and total soluble sugars were explored at flowering stage. Furthermore, significance of physiological traits in relation to adaptation of growth and yield under salt stress were also investigated. These studies revealed differential behavior of genotypes in their sodium uptake. Significant gradual increase in shoot sodium concentrations was observed under salinity at each stage of growth. Genotypic comparisons have shown that genotypes RST-177, RST -179, Shua-92-155/E, FL- 478, Kharaganja and IR-9 exhibited significantly low sodium concentrations and high potassium and sodium ratios. Highest sodium concentrations were observed in GML-528, GML-529 followed by GML-538. Results have also revealed variable increase in their total soluble sugars and proline concentrations. Highest concentrations of proline and total soluble sugars were found in GML-529, GML-538 and GML-528.Whereas, the lowest proline concentrations were observed in FL-478 followed by IR-9 and RST-177. Correlation studies among physiological traits revealed that the trait of sodium was significantly positively correlated at p<0.01with proline (r =0.7521) and sugars (r =0.8319) and negatively correlated with grain weight (-0.6923). The grain weight was negatively correlated with proline and total soluble sugars. Significant positive correlation of grain weight was observed only with K: Na ratio (r = 0.5355). On the basis of these studies it may be concluded that chlorophyll pigments, low sodium concentrations more specifically high potassium sodium ratios were observed as adaptive traits.

Response of Lactuca sativa L. ‘Babá de verão’ exposed to different substrates for laboratory bioassays

Plant bioassays are used to evaluate the biological effect of biotic and abiotic agents and its substrate must be carefully chosen. The objective of this study was to elucidate the effects of four different substrates (filter paper, agar, vermiculite and organic substrate) on the germination and initial growth of Lactuca sativa L. ‘Babá de verão’; 30 seeds were used for each treatment, with 3 replicates. After 7 days, the following parameters were evaluated: germination (%G) and emergence (%E) percentages, Germination (GSI) and Emergence (ESI) Speed Index, number of seedlings (NS), fresh biomass (FB), root length (RL) and shoot length (SL). Filter paper and agar were equally satisfactory for %G, GSI and NS; the same was observed for vermiculite and the organic substrate concerning %E, ESI and NS. The parameters FB, RL and SL were higher in the seedlings submitted to vermiculite and lower in the seedlings submitted to filter paper. It is concluded that vermiculite yielded the greatest seedling growth among the tested substrates; however, it does not allow the evaluation of germinative parameters, only emergence. In cases where it is essential to analyze germination parameters and evaluate seedling growth, agar is the most suitable substrate

Physiological and anatomical changes in Thai rice landrance (Oryza sativa L.) cv Pakaumpuel after colchicine treatment

Physiological and anatomical characteristics of the Thai rice landrace cv Pakaumpuel were investigated. Dehusked seeds were soaked in various concentrations of colchicine for 24 and 48 h in the dark, prior to washing in distilled water three times before germination. Two weeks’ old seedlings were cultured up to 16 weeks with transfer into bigger pots and physiological and anatomical parameters were recorded. The abaxial epidermis of mature leaves was examined by peeling technique, while leaf blade anatomy was investigated by transverse free hand section using 2% (w/v) Safranin as staining agent. Thirty-one anatomical characteristics were recorded. Results showed that colchicine treatment increased all growth parameters with the exception of tiller number. Eighteen anatomical characteristics showed significant differences after treatments including guard cell length, midrib thickness, and vertical and horizontal length of midrib and lamina vascular bundles. Effects of colchicine on growth and anatomical characteristics provide confirmatory evidence for polyploidy. This is the first report on Thai rice landrace anatomy. Basic data may be useful for product improvements in other rice cultivations.

The over-expression of a glycine-rich RNA-binding protein in Nicotiana tabacum and its roles in plant stress tolerance

Glycine-rich RNA-binding proteins (GR-RBPs) have been explored in different plant species for their role in development and environmental stress responses. NtGR-RBP1, a tobacco glycine-rich RNA-binding protein has recently been suggested as RNA chaperone with reference to protective role in bacteria upon exposure to various stresses. In the present study, we aimed to test the roles of NtGR-RBP1 in plants. The cDNA sequence of NtGR-RBP1 was amplified and cloned into entry vector using pENTR/D-TOPO cloning kit followed by sub-cloning into a plant GATEWAY® expression vector resulting in construction of pH7WG2-NtGR-RBP1. NtGR-RBP1 recombinants were confirmed through colony PCR and sequencing. Further, pH7WG2-NtGR-RBP1 was cloned into Agrobacterium tumefaciens AGL1 competent cells and confirmed by PCR after screening on streptomycin and hygromycin. The culture was subsequently used for the transformation of Nicotiana tabacum cv samsun by Agrobacterium-mediated plant transformation using the leaf disc method. Explants were screened using hygromycin as selection marker and later confirmed through PCR. Seed germination assay showed that NtGR-RBP1 had significant role in response to cold, heat and drought stress, while salt stress has negative effect on germination. Transformed plants will be used further for in depth functional characterization of NtGR-RBP1

Potassium humate amendment regulates soil NPK supply and growth parameters of potato (Solanum tuberosum L.) in a calcareous soil

Constrained nutrient supplies to plants grown in calcareous mineral soils are expected to diminish faster under a climate change scenario; therefore, we examined the potato vegetative and physiological responses to potassium (K) humate soil amendment applied in addition to the recommended doses of nitrogen-phosphorus-potassium (NPK) fertilizers. Hypothetically, K-humate regulates or improves NPK soil supplies and plant uptakes and hence, growth parameters of potato. Field experiments were conducted on potato (cv. Cardinal) grown at the Vegetable Research Farm, Bahauddin Zakariya University, Multan, Pakistan for two autumns (2010-2011). We used randomized complete block design with three repeats each of the NPK (0, 50, 75 and 100% of recommended dose: 120-80-80 kg ha^-1) and K-humate (0, 8, 12 and 16 kg ha^-1; 30% K) treatments. Individual soil NPK or K-humate application significantly improved (p £ 0.05) leaf chlorophyll content, final plant height, photosynthetic rate, stomatal conductance (S_c) and water-use-efficiency (WUE). We observed a significant interaction between NPK and K-humate for explaining additional significant improvements in these parameter values (except S_c; leaf chlorophyll 23%, plant height 41%, photosynthetic rate 34%, WUE 37%) as well as those of the number of leaves (55%) and leaf area (38%) per hill, and transpiration rate (27%). However, leaf chlorophyll content values in responses to 75 and 100% recommended doses of NPK did not differ significantly. Therefore, we conclude that K-humate can be used in calcareous soils in addition to the NPK fertilizer doses to mitigate the adverse effects of calcareousness (responsible for constraining the NPK uptake) by regulating the NPK soil supplies and plant uptakes, which improve potato vegetative and physiological growth parameters. 

Identification and heavy metals-induced expression analysis of the oligopeptide transporters (OPT) gene family in tomato

The oligopeptide transporters are membrane integral proteins playing pivotal role in translocating secondary amino acids, small peptides, organic nitrogen mobilization and contribute in variety of biological activities. In this study, we have performed comprehensive bioinformatic identification of tomato OPT gene family and a total of 16 OPT genes were identified in tomato. These proteins were classified into two subfamilies including PT sub-family and YSL sub-family with eight genes in each based on phylogenetic analysis. Moreover, OPT exhibited a unique gene configuration that was consistent with previously reported studies and validate its phylogenetic classification. The putative OPT gene family members exhibited diverse expression pattern and few genes express in specific tissues. For example, SlYSL1, SlOPT3, and SlOPT5 expressed in flowers and SlOPT1, SlOPT2, and SlYSL2 in roots. However, some genes showed high expression in fruits at various developmental stages. These include SlOPT6, SlOPT8, SlYSL3, SlYSL4, and SlYSL5. It was observed that expression of some SlOPTs were induced under heavy metals such as calcium, cadmium, iron, magnesium, potassium, and lead in both root and shoot. This suggested a potential involvement of these genes in tomato adaptation under stress. In summary, our work is the first comprehensive analysis of oligopeptide transporters in tomato and an important resource for prioritizing genes especially in metal ions mobilizing and nutrient deficiency stress adaptation

EST-SSR based analysis revealed narrow genetic base of in-use cotton varieties of Pakistan

Genetic improvement of cotton relies on extent of variation in germplasm. The in-use cultivars of Pakistan have been selected to assess genetic dissimilarities. A total of 44 cotton varieties/cultivars were selected for molecular analysis. These varieties were screened by 100 EST-SSR primers, selected on the basis of wider genome coverage. Analysis showed that the range of bands per primer varied from one to six. The average number of bands was 2.23 per primer. The range of PIC value varied from 0.28 to 0.94. The maximum PIC value of 0.95 was recorded for NAU-2503, considered as highly informative marker. A large number of markers, 73.07%, showed PIC value higher than 0.60 and considered highly informative. The results of dendogram showed that the in-use cotton varieties of Pakistan had very narrow genetic base. High similarity index existed among BT varieties as well. We observed very low genetic diversity in the selected varieties which are commonly grown in the country. There is need to include wide range of variation for genetic improvement in cotton. There is need to Introduce exotic varieties, Inter-specific hybridization, mutation breeding etc. may be used to avoid genetic bottle neck.

Phylogenetic relationships of two representative Lepidium species (Brassicaceae) in Qinghai province

Lepidium belongs to Tribe Lepidieae of the family Brassicaceae. There are about 15 species and one variety in China, which are distributed throughout the country. So far, the systematic studies of this genus at the species level still depends on morphological characters, and there is little data on their molecular phylogeny. A total of 162 specimens of Lepidium latifolium and Lepidium obtusum were collected from Qinghai Province. Combined with sequences from GenBank, the phylogenetic relationships of Lepidium were analyzed based on nrITS gene. The results showed that Lepidium clustered into a large clade (Clade A), in which L. hirtum together with L. campestre as a sister group of L. perfoliatum formed a sister clade (98/1) and was located at the bottom. In the middle part, L. densiflorum clustered with L. virginicum (100/1). At the top L. sativum, L. obtusum and L. latifolium L. apetalum L. ruderale formed parallel clades (61/0.83). These results were inconsistent with morphological data. Meanwhile, the haplotype network based on the sequenced nrITS sequences indicated that 6 haplotypes (Hap4-Hap9) of L. obtusum were obtained through a 22-step mutation from haplotype Hap1 from L. latifolium, and the initial haplotype (Hap9) was collected in Xining City, followed by one-step mutation into Hap4 which was widely spread in Qinghai Province. Hap4 transformed into other haplotypes by undergoing one-step mutation (Hap6, Hap7 and Hap8) or two-step mutation (Hap5), respectively. These results will provide the basis for future experiments and further accumulate data for molecular systematic studies of the Chinese Lepidium at species level

Phylogenetic relationships of genus Eriobotrya Lindl. (Rosaceae), based on nuclear ribosomal DNA (ITS) sequence

The phylogenetic relationships of genus Eriobotrya Lindl. (Rosaceae) was evaluated based on the  nuclear ribosomal internal transcribed spacers (ITS) sequence using 22 wild species of Eriobotrya, and 4 closest genera were used as an outgroup (Mespilus germanica L., Malus sieboldii (Regel) Rehder, Photinia beauverdiana C.K Schneid. and Rhaphiolepis indica (L.) Lindl.). Our results supported the view that the Eriobotrya species were monophyletic and suggested that E. condaoensis, E. henryi and E. seguinii as the most primitive group of Eriobotrya. Our results also suggest that E. grandiflora considered as a valid species and have close relationship to E. fragrans. We reported here three more taxa of the genus for the first time, E. hookeriana have close relationship with E. petiolata; E. bengalensis f. contractahave close relationship with E. malipoensis and E. bengalensis var. intermedia have close relationship to E. salwinensis and E. tengyehensis. Furthermore, it was also resolved that E. malipoensis have close relationship to E. bengalensis var. contracta. In addition, E. cavaleriei and E. fragrans were found to be distantly related to each other

Combining ability and stability studies in F₁ populations of Triticum durum across environments

In the developing world, plant breeding and seed improvement systems must be promoted to reduce the crops vulnerability. Development of improved genotypes of different crop plants through enlightened plant breeding are earnestly needed to deliver climate change adaptation and help in food security. Five durum wheat cultivars (Syrian–4, Dumes–1, Sham–7, Yousef–1 and Haurani) were crossed during 2016–17 in a half diallel fashion to create 10 F1 hybrids at Duhok University, Iraq. During 2017–18, the seeds of all the genotypes (five parental genotypes + 10 F1 hybrids) were grown with early (November 20, 2017) and late (December 20, 2017) sowing in a randomized complete block design (RCBD) with three replications at two different locations i.e., Sumel – Duhok University and Amedi – Duhok city, Iraq. The combined analysis of variance showed significant (p≤0.01) differences for hybrids, environments, and hybrid x environment interactions. Analysis of variance for combining ability showed that mean squares due to GCA and SCA were significant (p≤0.01) indicating the role of both additive and non-additive gene effects in inheritance of studied traits. In general, parental lines i.e., Sham–7 and Haurani were found as good general combiners for most of characters. The SCA effects were significant for three hybrids i.e., Syrian–4 × Sham–7, Sham–7 × Haurani and Duma–1 × Haurani for majority of the characters. In order to determine the stability of genotypes in four different environments, the stability parameters were used to identify the stable genotypes through regression coefficient (Bi) and variance of deviation from regression (S2d ). Results further revealed that genotypes differed in their response across various environments for all the variables. Some genotypes reflected stability for one character and unstable for other trait, showing a wide range of variation. According to stability parameters parental lines (Sham–7 and Haurani) and F1 hybrids i.e., Duma–1 × Haurani, Sham–7 × Haurani and Duma–1 × Sham–7, had the best stability for grain yield and its components, thus indicating a wide range of adaptation across environments. These investigations will play an important role in managing some strategies for improvement in durum wheat through diallel cross in future breeding program.

Conservation issues of Litsea monopetala (Roxb.) Persoon (Lauracae) in Pakistan

Economically important especially medicinal plants are facing threats of habitat alteration, habitat degradation, unplanned urbanization, over exploitation and unsustainable use practices and these threats are mainly responsible for the current species extirpation. Litsea monopetala is economically important medicinal plant. In Pakistan it was previously reported from Salt Range only, since, no specific locality was mentioned in the literature, therefore, in the present study L. monopetala could not be located in Salt Range in spite of our repeated efforts. However, after four years of continuous field studies during 2015 to 2018, three new localities were discovered i.e. Aba Chena Najigram (district Swat), Shoprang and Char Tambo (district Buner). A total of 218 mature trees were found in 3 localities in 2015, 214 mature trees were found in 3 localities in 2016, 192 mature trees were found in 3 localities in 2017, whereas, 179 mature trees were found in 1 locality i.e. Shoprang in 2018. Whereas, no individuals were found in Aba Chena Najigram and Char Tamboo during the year 2018. During the four years study in these 3 localities 1.84%, 10.28% and 6.77% decrease has been observed in its total population size, respectively. The main threats faced by the taxon were its habitat alteration, agricultural land extension, unsustainable lopping and bark pealing. The bark of Litsea monopetala is sold in the local and national market for its medicinal properties by the local community. Following the IUCN Red List Categories and Criteria 2001, based on its extent of occurrence (EOO) of 293.77km², area of occupancy (AOO) of 20 km² and population size of 179 mature trees, the taxon is categorized as Critically Endangered (CR). Since, the taxon is found in the community owned lands adjacent to their cultivated fields therefore; it is recommended that awareness raising campaigns should be arranged for effective management of the taxon in its natural habitat.

Karyotypes in 12 populations of Allium caeruleum from Tianshan mountains, Xinjiang, China

Xinjiang is an important natural habitat for the wild genus Allium in Central Asia. The karyotypes of 12 populations of Allium caeruleum from Tianshan Mountains, Xinjiang, China were investigated in this paper. Results showed that all of the tested materials were diploid (2n=2x=16) which had M, m, sm and st types and the percentage of the total chromosome number was 1.04%, 68.75%, 25.00% and 5.21%, respectively. The satellite existed in six populations. The compositions of chromosome relative length were L, M2, M1 and S types. The percentage karyotype asymmetry index was 58.58% to 62.70%. Karyotypes was 2A or 2B. The higher evolutionary trend of karyotypes was in Zeketai population. The four groups were clustered at 5.5 genetic distance. The genetic diversity of chromosome compositions and unstable satellites were in 12 populations. The changes of chromosomes structure results in the genetic variability for adaptation of new habitats and it is one of the evolutional strategy.

Evaluation of nutritional potential of wild edible fruits consumed by indigenous communities of central Punjab, Pakistan

The current study was based upon nutritional value of wild edible fruits consumed by rural people in Central Punjab, Pakistan. The study area is gifted with fertile agricultural land that is blessed with arid and semi-arid climatic conditions. However, uncultivated landscapes in the region are occupied by wild flora including wild edible fruits. This work focused on the consumers of wild edible fruits in the indigenous communities because of their vast traditional knowledge on the nutritional importance of indigenous wild species. A total of 27 wild edible fruit plants were recorded in the area belonging to 16 families. All the plants were native and have occupied the area for decades or centuries. Ziziphus nummularia, Morus nigra and Morus alba were found to be the most abundant and consumable species. The most rarely occurring species were Asparagus officinalis, Cocculus hirsutus, Cordia gharaf and Grewia tenax. The plant samples were collected, identified, preserved and deposited in the Herbarium of University of Sargodha (SARGU) for future reference. Fruit samples were subjected to proximate analysis such as moisture, crude protein, crude fat, crude fiber, ash and nitrogen free extract (NFE) contents to evaluate their nutritional importance. Moisture content, crude protein, crude fat, crude fiber, ash and NFE ranged from 9.36 to 84.05%, 0.18 to 3.68%, 0.12 to 5.46%, 0.32 to 45.43%, 0.17 to 19.68% and 32.52 to 99.03% respectively. Thus, these wild edible fruits were found promising alternatives of food

Ecological evaluation of existing plant resources of Manrai hills, Swat, Pakistan using multivariate analysis

Like other montane temperate forests in Pakistan, vegetation of Manrai hills, Swat is declining at an alarming rate due to anthropogenic pressure, although they represent abode of plant biodiversity and need special care and attention. Keeping this motive in mind, the area was studied to evaluate the existing vegetation during 2012-2016. Species and environmental data from 50 quadrats by using stratified random sampling viz., 1x1m², 2x2m² and 10x10m² for herbs, shrubs and trees, respectively were placed in TURBOVEG (v. 2.101) software and transferred to JUICE (v. 7.0.102) software for establishing reliable clusters. From the sampled area, a total of 270 species of vascular plants were recorded. Three communities viz., 1) Quercus-Sarcococca-Pinus, 2) Iris-Poa-Arenaria and 3) Abies-Picea-Viburnum were determined through standard default parameters of modified TWINSPAN. All communities showed distinct strata with clear demarcation of tree, shrub and herb layers. On an average, tree, shrub and herb layers were occurred at 13.52±7.62m, 0.90±0.39m, 35.0± 7cm, respectively. Average Species richness (21.38±5.29), Shannon-Wiener (2.56±0.32), Simpson (0.88±0.05) and evenness (0.85±0.06) indices were comparatively higher in comparison to other studies from Pakistan. Canonical Correspondence Analysis (CCA) run through PC-ORD (v.6) indicated that topographic, edaphic and anthropogenic factors as the main determinants of community types. Lopping, deforestation and overgrazing are serious ecological threats to the vegetation of the area. Practical and workable measures for conservation of this valuable bio-resource are suggested considering our findings

Effects of grazing intensity on sexual and clonal reproduction in a clonal xerophytic shrub

Many plants can reproduce both sexually and clonally, with different consequences for the dispersal, distribution and long-term fitness of plant populations. Understanding the factors and underlying mechanisms that mediate the trade-offs between the two reproduction modes has long been of interest to biologists and ecologists. This knowledge is critical for better understanding the dispersal and sustainability of plant populations in changing environments. Herbivory affects plant growth, and yet how herbivory affects the reproduction mode in clonal flowering plants still remains unclear. In this study, we studied the influence of grazing on the reproduction mode and traits of a dominant xerophytic shrub Caragana brachypoda Pojark using field experiments that under three grazing intensities. Our results showed that both sexual and clonal reproduction of C. brachypoda decreased as grazing intensity increased. Thus, grazing disturbance will likely lead to an aging population structure. Moreover, the proportion of sexual reproduction versus clonal reproduction of this species significantly decreased as grazing intensity increased (with sexual reproduction decreasing to 0% under intensive grazing), which will likely decrease genetic diversity and reduce adaption potential to varying climate conditions over the long run. In addition, because grazing affected seeds and distal ramets more than proximate ramets, it is likely to create a more aggregated distribution pattern of plants, which in turn would enable livestock to graze on this shrub species even more easily due to reduction in travelling costs. Our results suggest that grazing can affect both sexual and clonal reproduction in clonal plants, and can affect mode of reproduction. The effects of grazing on plant reproduction mode are likely to ultimately affect population age structure, population genetic diversity and population distribution patterns, thereby influencing the long-term future of populations even when grazing appears to be sustainable based on plant density

Investigation of phytochemical, anti-microbial activities of Justicia gendarussa and Justicia adhatoda

The aim of the study was to explore the Phytochemicals (Alkaloids, Flavonoids, Terpenes, Tannins, Saponinsand Phenols) in root, stem and leaves of Justicia gendarussa and Justicia adhatoda and to correlate it with inhibition of microbes.Alkaloids, flavonoids and phenols were present in both the selected plants while saponins were not detected in the same plants.All fractions of root stem and leaves samples of Justicia gendarussa were active against the selected bacterial strains Enterococcus faecalis, Salmonella typhii, Proteus mirabilis, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae except n-hexane fraction of the plant which was fund inactive. Among fractions obtained from root of Justicia gendarussa, the chloroform fraction showed highest zone of inhibition 27 mm against Staphylococcus aureus. While the crude extract and fractionsderived from different parts of Justicia adhatoda showed moderate to good activities against all tested bacteria giving range of inhibition zones from 14 mm to 28 mm. our research plants also showed good antifungal activities against the four tested fungi. 

Superior provenance and plus tree selection for Betula alnoides in southern Fujian China

The 14-year-old provenance and family test plantation of Betula alnoides in Fujian Hua'an Jinshan National Forest Farm was investigated. Eight growth traits, including tree height, diameter at breast height (DBH), individual volume, height to crown base, crown diameter, crown form index, stem form index and branching index, were analyzed for all 25 provenances tested. The superior provenances were selected: Provenance G (Tengchong, Yunnan) performed the best, followed by Provenance L (Jiangcheng, Yunnan) with the best stem form; Provenance U (Pingguo, Guangxi), J (Fengqing, Yunnan), R (Tianlin, Guangxi), C (Mojiang, Yunnan) and P (Longzhou, Guangxi) were the alternative. These provenances were not severely damaged by trunk borer. It is suggested the seeds for nursery should be collected from the Provenance G or L for plantation forestry of B. alnoides in Southern Fujian, and Provenance U, J, R, C and P could be used for the alternative seed sources. 182 plus trees were also screened out and could be applied for grafting and tissue culture

Effects of row spacing and plant growth regulation on alfalfa seed yield (Medicago sativa L.)

The influence of sowing method, growth regulator and harvest method on alfalfa seed yield was examined in three years (2015-2017), in locality near Belgrade, with using alfalfa variety NS Banat ZMS II. Research showed the statistically very significant effect of sowing method on seed yield, and the best average way for all three years period was 60 cm between rows of sowed seed. The growth regulator proved to be effective only in the rainy year, while harvesting crops previously treated with desiccant proved to beuseful, with the exception in the year of establishment when this difference was not statistically significant. Meteorological conditions had the highest influence on the seed yield, amount of precipitation in the vegetation period mostly, and the researched factors have proved to be useful in suppressing the consequences of poor weather. In years suitable for seed production, the recommendation for the production practice is an intermediate distance of 60 cm and the use of a desiccant

Seasonal variations of metabolite content in phloem sap from Broussonetia papyrifera

Phloem sap not only services important physiological function in tree growth but also can be selected for a potential raw material in chemical industrial products. As a tree species from Moraceae, Broussonetia papyrifera (BP) contains rich phloem sap.In order to investigate the phloem sap content and the variation during tree growh, Gas chromatography-mass spectrometry was employed to analyze the metabolites in phloem sap of BP, with a focus on seasonal variations in metabolite content. A total of 38 metabolites were detected in BP phloem exudates, with the highest content (44.59mg g^-1) of total metabolites observed in March. Moreover, large amounts of organic acids and sugars were detected in BP phloem exudates for all growing months, as well as lower amounts of fatty acids and alcohols. Metabolites associated with anti-cancer and anti-inflammation properties (e.g. PI3 kinase inhibitor, Chlorogenic acid, Chelerythrine and palmitic acid) were also detected. Quininic acid was the most abundant organic acid, representing up to 86.3% of all organic acids. In addition, D-fructose, D-glucose, and sucrose were the principle soluble sugars observed in phloem saps, with a maximum sugar content of 19.76mg g^-1 in November. Seasonal changes in the metabolite content varied among individuals. Results of the metabolite analysis confirmed the role of BP phloem sap as an important resource for the synthesis of both pharmaceutical and human health products. All the results suggested that phloem sap content changes with the tree growth season.

Effects of press-formed crop residue rice seedling tray on the physiological characteristics of machine-transplanted rice seedlings

This study aims to analyze the intrinsic relationship between substrate type and the physiological characteristics of seedlings. It also aims to evaluate the applicability and universality of seedling substrates. Natural soil (CK) and a commercial mixed substrate (T1) were used as controls, while bulk straw substrate (T2) and straw seedling board substrate (T3) were taken as research objects. The effects of straw seedling substrate, specifically plate straw seedlings without a plastic plate, on the growth characteristics and seedling quality of rice seedlings were studied. Results showed that the bulk densities of the T2 and T3 were significantly lower than those of the control by 74.11% and 59.82%, respectively (p<0.05). Aeration pores, water holding pores, and nutrient contents were significantly higher in the test groups than in the controls (p<0.05), and the raising process was simple. The growth characteristics of seedlings and roots grown in T2 and T3 were significantly better than those of the control treatment (p<0.05). Roots were agglomerated and the leaf age, plant height, amount of dry matter in the above-ground parts, and stem base width of the test groups were significantly higher in the test groups than in the control treatment. The physiological indicators of the seedlings suggested that the respective SOD and POD contents of seedlings raised in T3 were 40.80% and 16.76% higher than those of seedlings raised in T1. However, the MDA content of this group was lower than that of the control, which indicates that T3 improves the stress resistance of rice. The binding ability and contents of total nitrogen, soluble sugar, starch, and chlorophyll of the T3 and T2 were higher than those of CK and T1. The findings suggest that seedlings raised in the straw seedling substrates have strong growth potential, which is conducive to their growth in the field after machine transplantation, and lays a solid foundation for research on high-yield agriculture.

Establishment of selection criteria for fibre quality characters in segregating F₄ and F₅ generations of cotton (Gossypium hirsutum L.)

The Research work was conducted at NIAB, Faisalabad and consists of three combinations of both F₄ and F₅ populations along with their parents and check varieties. In F₄ generation significant differences for fibre strength and lint weight were observed whereas in F₅ generation significant difference in micronaire, maturity, fibre length, fibre strength, lint weight were observed. Cross combination NIAB-2008 x MNH-886 form F₄ generation and from F_5, cross combination NIAB-852 x MNH-886 followed by NIAB-777 x MNH-886 showed high mean values for fibre maturity, lint weight, micronaire and seed cotton yield per plant. In F₄ and F₅ generations, seed cotton yield per plant was significantly and positively correlated with ginning out turn (GOT %), fibre maturity, fibre length, micronaire and lint weight at genotypic level. In both F₄ and F₅, path coefficient analysis showed that ginning out turn, fibre uniformity, fibre strength and lint weight had direct positive effects on seed cotton yield at both phenotypic and genotypic lecel. From the present findings it is concluded that cotton breeders can enhance the efficiency of selection with the help of information generated on the relationship between components associated with fibre quality and yield itself in the early generations. Both F₄ and F₅ generations exhibited highest direct effects combined with positive correlation in ginning out turn%, fibre length and lint weight with seed cotton yield. The result showed that while making seslection these fibre traits should be given more emphasis.

Characterization of cellulases from thermophilic bacilli and their application for the saccharification of sugarcane bagasse

Cellulases from thermophilic bacteria are likely to be more stable and are required in countless biotechnological applications. Bacillus being a house of thermostable proteins has frequently been studied for the production of cellulases. During the process of composting, distinct temperature changes are observed including significant rise that favors the growth of thermophiles with the ability to degrade plant based waste materials. Therefore, isolation of bacterial strains was carried out from a composting site; screening of the isolates revealed capability of three of the isolates, MAH14, MAH66 and MAH80, to produce endoglucanase (EG) and b-glucosidase (BGL) at 50°C. On the basis of biochemical characters MAH66 and MAH80 were identified as the strains of Bacillus licheniformis whereas, MAH14 was identified as Bacillus subtilis. The cellulase preparations from these bacteria were studied for their thermostability by investigating the half-life (t_1/2) and melting temperature (T_m). The MAH80 cellulase exhibited more stability with a T_m of 60°C and a t_1/2 of 70 min at 50°C.The prospected application of cellulase crude preparation from the strains was estimated by carrying out experiments on the saccharification of untreated and alkali-treated sugarcane bagasse (SB) and the data was compared with the saccharificaiton of CMC. Hydrolysis rate from MAH14 of untreated SB was higher as compared to alkali pretreated SB and CMC. The amount of reducing sugars liberated by the action of cellulase preparation from MAH 66 on untreated SB (1.7 mg mL^-1) was higher than on alkali treated SB (0.29 mg mL^-1). While the enzyme from MAH14 yielded almost equal amount of sugars when applied either on alkali treated SB (0.56 mg mL^-1) or on CMC (0.6 mg mL^-1). Results from this study revealed the capability of indigenous thermophilic bacterial strains for cellulase production and biomass saccharification

Pattern of post-harvest fungal infestation on vegetables stored in various vegetable markets of Karachi

We isolated and identified 17 genera and 25 species of fungi from five vegetable crops including Bitter gourd (Casia Momordica), Garlic (Allium sativum), Okra (Abelmoschus esculentus), Onion (Allium cepa) and Potato (Solanum tuberosum) from five major vegetable markets of Karachi viz, Gulestan e Johar, Landhi, Nazimabad, New Sabzi Mandi and Saddar Empress Market. Among all isolated fungal flora; the fungi A. niger, Rhizopus stolonifer, Colletotrichum gloeosporioides, Botrytis cinerea and Fusarium oxysporum were the most common species causing the post-harvest decay of the target vegetables. Blotter paper method yielded more number of mycoflora with higher frequency over the agar plate method. In pathogenicity test, Aspergillus niger showed the highest rot diameter of 40.33mm on onion while it appeared as the lowest rot diameter of 7 mm on okra. The higher fungal infestation (34.84%) was recorded on vegetables that were stored or sold in Sabzimandi and the least fungal infestation (3.63%) was found on vegetables stored n Landhi. Vegetables are an essential part of our diets, therefore, we must keep our vegetables clean and free of diseases.  Thus we surveyed a few large vegetable markets in Karachi to identify post-harvest mycoflora associated with various commonly used vegetables in our diets. We used blotter paper as well as Potato Dextrose Agar (PDA) methods to isolate and identify the fungal species infecting vegetable crops.

Fruit quality of ‘Valencia’ orange trees grafted on volkameriana and sour orange rootstocks grown in two different regions in northern Cyprus

The present study aimed to identify the effects of two citrus rootstocks (Sour orange and Volkameriana) on the fruit quality of ‘Valencia’ orange. Studies were carried out in Gaziveren and Lefke regions, located in Northern Cyprus. According to the results, some of the fruit quality parameters were affected by rootstock in ‘Valencia’ orange variety. In Lefke region, it was identified that the rootstocks play important role in terms of the fruit weight at ‘Valencia’ orange trees. The highest individual fruit weight and the biggest fruits at ‘Valencia’ orange trees were measured on Volkameriana rootstock. The highest juice amount was measured from ‘Valencia’ orange trees grafted on Volkameriana rootstocks (55.70%) and the lowest amount was determined in ‘Valencia’ orange trees grafted on Sour orange rootstock (54.10%). In Gaziveren region, rootstocks were found to affect soluble solid concentration in fruit juice. ‘Valencia’ orange trees grafted on Volkameriana rootstock found to be the lowest Total Soluble Solid (TSS) content. The fruit juice content of the ‘Valencia’ orange trees grafted on the Volkameriana and Sour orange rootstocks were measured as 57.09% and 55.55%, respectively. The results about the juice content of ‘Valencia’ orange trees grafted on two different rootstocks did not have statistically significant differences. Titratable acidity (TA) of the fruits was measured as 1.45% from the plants grafted on Sour orange rootstock and as 1.20% on Volkameriana rootstock. The TSS/TA of the ‘Valencia’ orange were also measured as 9.39 on Volkameriana rootstock and as 8.13 on Sour orange rootstock.

Strain improvement by random mutagenesis of Aspergillus tamarii RMLC-10 for improved biosynthesis of polygalacturonase

Increasing and inevitable applications of polyagalacturonase in food and poultry feed industries urged the researchers to develop improved fungal strains for its industrial production. Polygalacturonase producing a wild strain of Aspergillus tamarii RMLC-10 was exposed to physical i.e. UV rays and chemical, i.e. Ethyl methanesulfonate (EMS), sodium azide and nitrous acid treatment to develop a mutant strain. This resulted in the development of forty-five variant strains. Among these, sodium azide treated a mutant strain of Aspergillus tamarii SA-11 showed a maximum increase in enzyme activity i.e. 32.01±0.09 U/ml compared to wild strain RMLC-10 with the enzyme activity of 24.57±0.04 U/ml. Effect of different cultural conditions such as incubation time, temperature and medium pH on polygalacturonase activity of wild and mutant strains was assessed. This showed an increase in enzyme activities of both wild (27.18±0.02 U/ml) and mutant (34.67±0.06) strains after an incubation time of 72 h at 30℃ in a fermentation medium of pH 6.

Effect of nano-ZnO on activity of wheat fusarium head blight pathogen

The effects of nano-ZnO on the inhibition efficiency of the activity of wheat Fusarium head blight pathogen, wheat seed germination, and seedling growth were investigated, and the feasibility of using it as a novel seed treatment agent was determined. Results showed that (1) the survival rate of pathogenic conidia was significantly reduced when the nano-ZnO concentration was 50 mg L^–1. The survival rate was dropped to the lowest when the nano-ZnO concentration was 100 mg L^–1, and the growth of the mycelium of Fusarium head blight pathogen was significantly inhibited when 100 mg L^–1 was applied. (2) Nano-ZnO treatment increased germination rate, seedling length, root length, and dry matter weight to different degrees. When treated with nano-ZnO at a concentration of 50 mg L^–1, nano-ZnO significantly improved infested wheat seedlings, while the superoxide dismutase (SOD) and catalase (CAT) in vivo activities and malondialdehyde (MDA) content were decreased. (3) Nano-ZnO had no adverse effects on the seed germination and seedling growth of healthy wheat. It also increased SOD and CAT activities in early seedlings and decreased MDA content. Therefore, nano-ZnO not only inhibits pathogen activity and increases seed germination rate but also has a certain role in promoting the growth of healthy seeds. These results show an important application prospect for nano-ZnO that can be applied to crop seed treatment to prevent seed diseases

Molecular diversity of halophilic fungi isolated from mangroves ecosystem of Miani Hor, Balochistan, Pakistan

To find the halophilic fungal biodiversity hundred soil samples were collected from mangrove ecosystem of Miani-Hor Balochistan.  Miani-Hor lagoon is about 50 km long with a single inlet from sea. Out of hundred soil samples 14 different halophilic and halotolerant microorganisms were isolated. Growth characteristics along with microscopy delineated diversity of the halophilic fungal isolates. To determine the molecular level identification and classification, DNA extraction and consequently sequencing was done.  Molecular biodiversity was determined by internal transcribed spacer region of fungus. Molecular identification along with phylogenetic tree determination was achieved by using ITS regions of the species belonging to the genus Aspergillus (4 isolates), Penicillium (4 isolates), Alternaria (3 isolates), Fusarium (1 isolate) and Pleosporaceae (2 isolates). Diversified halophilic and halotolerant fungi from mangroves ecosystem in Pakistan will open doors for the application of indigenous species as a biorefineries.

Rhizobia strains alleviate salinity in faba beans (Vicia faba) to valorize marginal sols

Soil salinity remains the most limiting parameter for the growth and enhancement of Vicia faba L (faba bean) in Tunisia. Plant growth promoting rhizobacteria abbreviated as (PGPR) has emerged as a novel way to minimize the negative effects of salinity and improve the nutrient accessibility. The objective of this work is to investigate the protective effects of two newly isolated PGPR (rhizobia stains S1 and S2) over 150 mM NaCl salinity stress. Physiological, biochemical parameters and antioxidant enzymes activities in faba bean culture were measured. The Results showed that salt stress increased nodule biomass in plants inoculated by S1 with significant difference compared with plants inoculated by S2. Salinity considerably augmented the level of nitrogen in root and shoot if it was inoculated by S1 while no change was observed with S2 inoculation. Under salt stress, the higher content of K+ and Na+ level was observed in plants inoculated with S1 than in plant inoculated by S2. EL showed a high increase (80%) in leaves of plant inoculated with S2 was observed under 150 mM NaCl against (10.71 %) in leaves of plant inoculated with S1 after 10 days of inoculation. After 30 days of inoculation under salinity faba bean-S1 showed the higher value of PPO (8.86 µmol g-1FM) and without salt, the PPO activity was 2 µmol g-1FM. After 40 to 50 days of inoculation, plants inoculated by S1 and S2 showed the higher values of phenol content under salinity. The results indicated that salinity significantly increases the proline accumulation by the leaves and root of faba bean inoculated with S1. But chlorophylls level was not affected. This study indicates that the S1 rhizobia strain is a prospective inoculant candidate which is essential for promoting growth and production, and thereby reducing the effect of salinity on faba bean plant.

Bacillus amyloliquefaciens and Alcaligenes faecalis with biogas slurry improved maize growth and yield in saline-sodic field

Abiotic stresses are among the major threats in agriculture to achieve optimum growth and yield of crops. Besides other abiotic stresses, salinity and sodicity problems are centre of attention. Higher uptake of undesirable salts, hamper the growth of plants. These salts increase the production of stress ethylene, exerting negative effects on growth. In addition, imbalance in nutrients uptake drastically decrease the yield of crops. To overcome the problem of salt stress, use of plant growth promoting rhizobacteria (PGPR) is an efficacious technique. However, to increase the efficacy of this technique, use of organic amendments with PGPR is mostly suggested. Therefore, the current study was conducted to examine the role of ACC deaminase producing rhizobacterial strains i.e. Bacillus amyloliquefaciens and Alcaligenes faecalis in separate and conjoint with biogas slurry (BGS) on growth and yield of maize in saline-sodic field conditions. Recommended Nitrogen (N), phosphorus (P) and potassium (K) fertilizers (NPK) were applied to fulfill crop nutrients requirement. Application of Alcaligenes faecalis+BGS+NPK gave maximum increase in plant height (16%), number of grain cob⁻¹ (17%), 1000-grain weight (16%), total chlorophyll content (11%), carotenoids (1.9 fold), anthocyanin (2.3 fold), shoot P (32%), shoot K (15%), grain N (23%), grain P (51%), grain K (27%), grain yield (51%) and straw yield (66%), over control. In conclusion, A. faecalis proved more effective as compared to the B. amyloliquefaciens. Both the PGPR strains, B. amyloliquefaciens and A. faecalis have potential to improve maize growth and yield when applied in combination with BGS under saline sodic condition.

Development of a dCAPS marker based on a minor resistance gene related to head smut in BIN8.03 in maize

Head smut can cause maize yield losses of up to 80% in the maize-growing region of Northern China. Molecular markers based on candidate resistance genes have proved to be useful for highly sensitive selection of resistance in maize breeding programs. In the present study, a SNP (single-nucleotide polymorphism) in resistant and susceptible maize lines was identified within the nucleotide-binding site (NBS)-leucine-rich repeat (LRR) gene GRMZM2G047152 in bin 8.03. Using this SNP, we developed the derived cleaved amplified polymorphic sequence marker DNdCAPS8.03-1. The molecular coincidence rate of the combination of markers DNdCAPS8.03-1 and LSdCAP2 (related to the QTL qHS2.09) was higher than that of a single marker in a set of 56 inbred maize lines belonging to five heterotic groups. These results provide information and tools that will prove to be useful in marker-assisted selection (MAS) in breeding maize for head smut resistance

Thermal stress alleviating potential of endophytic fungus Rhizopus oryzae inoculated to sunflower (Helianthus annuus L.) and soybean (Glycine max L.)

Agricultural crops including sunflower and soybean are facing thermal stress because of rapid change in climate caused by global warming. Some innovative steps should be taken on an emergency basis to prepare plants for such unfriendly stressful conditions. Use of endophytic fungi might be one of the successful weapons to protect food crops, susceptible to high temperature. These endophytes are known to secrete vital stress responsive secondary metabolites that not only provide resistance to crops against abiotic stresses but also help in promoting plants-growth and yield. Therefore, endophytic fungi were isolated from the leaves and roots of Adiantum capillus-veneris L. and their potential were checked for secreting bioactive secondary metabolites and possessing plant-growth promoting potential. A high concentration of phenolics, flavonoids, salicylic acid (SA) and indole 3-acetic acid (IAA) were found in the culture filtrate of isolate AdR-1, thus confirming their growth promoting potential for plants. Later on, phylogenetic exploration and 18S rDNA sequence homology showed that the selected isolatic fungus is Rhizopus oryzae.  This strain was inoculated to sunflower and soybean seedlings exposed to normal (25°C) and high (40°C) temperature stress in a growth chamber and their potential for thermal stress resistance was compared with control seedlings. Inoculated sunflower and soybean plants had shown low level of abscisic acid (ABA) while, high levels of ascorbic acid oxidase (AAO), catalase (CAT), proline, phenolics, flavonoids, sugars, proteins and lipids were noted. The endophytic fungus was also found stimulatory to chlorophyll content, shoot and root lengths, fresh and dry biomass as compared to un-inoculated plants. These results confirmed the beneficial role of R. oryzae for crop plants under thermal stress and suggested their use for sustainable agriculture in the future

Development of sequencing technology and role of next generation sequencing technologies in wheat research: a review

Sequencing is a fundamental component in the life science research. Sanger method known as first-generation sequencing technologies (FGSTs) was the first successful sequencing method introduced in 1977. Considering time and financial advantage, second-generation technology was introduced in 2005 which is also called as next-generation sequencing technologies (NGSTs). These technologies have significantly high throughput compared with FGSTs, and make break through revolution in the study of genomics and molecular biology. To overcome the mandatory sample amplification regarding the read length and the bias of the NGSTs, third-generation sequencing technologies (TGSTs) were introduced. Third-generation long-range sequencing and mapping approaches are making a renaissance in high-quality genome sequencing. The recent developments of the fourth generation sequencing methods hold great promises and expect to offer most important contribution in these key areas. Currently, NGSTs use most of the genomics field, third-, and fourth-generation approaches make a significant solution in the genomics era. Wheat is one the major crop species which is closely related with the development of agriculture and straighten of societies. The demands of wheat are increasing day by day which necessitate improvement of wheat genomics and functional genomics. Wheat yield has been accelerated by the advances of NGSTs that focused genome sequencing, genomic polymorphism, genes cloning and development of technical platforms. This review discussed about the development of sequencing technologies, wheat development through NGSTs and future outlook. This review is mostly targeted for the beginners (new students/ researchers) who have intended to work with NGSTs

Mechanisms of plant response to salinity stress: current understanding and recent progress

Salinity is considered as a major abiotic stress for plants as it challenges plant growth and productivity severely. Plants have developed plenty of biochemical, physiological and metabolic strategies to deal with salt stress at multiple levels. A better understanding of these contrivances is an important step towards achieving the goal of sustainable development of agriculture. This review aims to provide a brief overview of our current understanding of plant salt-tolerance mechanisms from five aspects: specialized salt glands, ion homeostasis and osmotic adjustment, antioxidant defense system, hormonal regulation and modifications in membrane composition. Finally, we highlight unsolved issues that remain to be addressed in future studies