POLLEN FLORA OF PAKISTAN - IX. PAEONIACEAE
ABSTRACT:
Pollen morphology of the family Paeoniaceae from Pakistan has been examined by light and scanning electron microscope. Pollen grains are generally radially symmetrical, isopolar prolate-spheroidal, 3 zonocolporate, colpi long. Tectum rugulate-striate.

A NEW SPECIES OF THE GENUS CODIUM STACKH., FROM THE COAST OF PAKISTAN
ABSTRACT:
A new taxon Codium shameelii Nizam., characterised by coxcomb-like tenninal proliferations has been described from the coast of Pakistan.

OBSERVATIONS ON GELIDIUM PUSILLUM (STACKH.) LE JOLIS (RHODOPHYTA) FROM THE COAST OF PAKISTAN
ABSTRACT:
The vegetative, anatomical and reproductive structures of the Pakistani populations of Gelidiurn pusillurn (Stackhouse) Le Jolis have been investigated. The plants showed distinctive features with turf or cushion forming habit; upto 11 mm in length and appear distinctly segmented in microscope; primary erect fronds tereto-compressed below becoming flat in the upper half; random arrangement of surface cells as well as tetrasporangia; tetrasporangia borne in stichidia-like structures as well as on the tips of branch fronds; sexual plants not found; and abundance of rhizines.

ALGAL EPIPHYTES ON MANGROVES OF BALOCHISTAN, PAKISTAN
ABSTRACT:
Twenty one species of algae were found growing as epiphytes on the pneumatophores of mangrove Avicennia marina (Forssk.) Vierh. They appear to be new reports as epiphytes on mangroves of Pakistan except for Chaetomorpha gracilis Kutzing, Enteromorpha torta (Mert.) Reinbold, Lyngbya majuscula Gomont, Polysiphonia abscissa J. Hooker et Harvey. Most species occupied middle position on the pneumatophores indicating avoidance from both long-term exposure and submergence.

ONIDIAL APPENDAGES AS TAXONOMIC CRITERIA IN COELOMYCETES
ABSTRACT:
Conidial appendages have been used as a taxonomic criteria in Coelomycetes. A modified conidial appendages classification has been proposed.

ISOZYME POLYMORPHISM IN ASCOCHYTA RABIEI ISOLATES FROM PAKISTAN
ABSTRACT:
Fifteen isolates of Ascochyta rabiei causing blight of chickpea (Cicer arietinum) were collected from Pakistan and analyzed for esterase, acid phosphatase, alcohol dehydrogenase, lactate dehydrogenase, malate dehydrogenase, glutamate dehydrogenase and fumarase. Only two enzymes viz., esterase and acid phosphatase produced qualitative as well as quantitative differences among the isolates of A. rabiei. Six electrophoretic phenotypes were developed in case of acid phosphatise, whereas isoelectric focusing of the protein extracts revealed simpler banding patterns for the esterase activity on gel. No correlation between isozyme patterns and the pathogenic groups were established on the basis of aggressiveness.

FUNGI ASSOCIATED WITH WILT DISEASE OF CAPSICUM IN SINDH, PAKISTAN
ABSTRACT:
Out of 16 genera and 28 species of fungi isolated from soil, at least 7 genera and 10 species of fungi were isolated from root, stem, leaves and seeds of infected plants of bell pepper (Capsicum annuum) as compared to 7 genera and 11 species from red pepper (C. frutescens). Alternaria altemata, Cephalosporium acremonium, Fusarium anthophilum, F. moniliforme, F. oxysporum, F. proliferatum, F. solani, Macrophomina phaseolina, Pythium aphanidermotum and Rhizoctonia solani were found predominant in plants showing symptoms of wilting in Mirpur Khas District, Sindh, Pakistan.

VIABILITY OF VAM SPORES FROM WHEAT FIELDS IN SOIL BASE CULTURE UNDER STORAGE
ABSTRACT:
Axenic soil base VAM cultures of 6 different Glomus spp., viz., Glomus fasiculatum, G. macrocarpum, G. monosporum, G. mosseae, G. radiatum and G. warcupii extracted from the soil of wheat field and stored separately in pots at 5 and 10 (±l)°C or kept under natural conditions showed a gradual loss in viability in 2 yeats. Loss in viability of spores was significantly higher (p < 0.001) when the axenic culture of Glomus spp., were stored under natural condition with temperature ranging from 10-25°C during winter and 22-38°C during summer season. G. macrocarpum retained highest viability (p<0.001) after 2 years.

ESTIMATION OF YIELD LOSSES IN CORN DUE TO STALK ROT PATHOGENS
ABSTRACT:
Pathogenicity of Fusarium moniliforme, F. graminearum and Macrophomina phaseolina isolated from stalk rot disease of corn were tested on a susceptible com cv. Shaheen in different seasons and at different stages of plant growth at the National Agricultural Research Centre (NARC), Islamabad, Pakistan. F. moniliforme and M. phaseolina in combination produced 77.9 and 89.0% infection with respectively 21.7 and 25.9% reduction in grain yield during spring and summer seasons of 1988, whereas F. graminearum produced 32.8 and 49.4 % disease severity with 0.9 and 1.4 % reduction in grain yield during the same spring and summer seasons.

USE OF CELLULAR FATTY ACIDS IN THE CHARACTERIZATION AND DIFFERENTIATION OF BACTERIAL LEAF STREAK ATHOGENS ON MILLET
ABSTRACT:
Analyses of cellular fatty acids (FAs) were used to identify bacterial leaf streaking pathogen(s) infecting foxtail and pearl millet in Colorado, USA. Isolates from both hosts were identified as unknown pathovar(s) of Xanthomonas campestris. To detennine any similarity the most discriminatory FA profiles of the US isolates were compared with those of X. campestris. pv. pennamericanum infecting pearl millet in Africa and 11 other X. campestris pathovars infecting members of the Poaceae family. The US isolates were different from X. campestris. pv. pennamericanum and the other X. campestris pathovars but similar among themselves. When a dendogram of the millet isolates was constructed with 35 other X. campestris pathovars, the different nature of the US isolates was further clarified. However, this evidence was not enough to give the American isolates a separate pathovar status.

GROWTH PROMOTION OF TWO WHEAT CULTIVARS BY PLANT GROWTH-PROMOTING RHIZOBACTERIA
ABSTRACT:
Based upon their ability to produce auxins (indole-3-acetic-acid equivalents), 11 isolates of rhizobacteria were selected to evaluate their growth promoting activity. Seeds of 2 wheat cvs. Inqlab and LU 26S inoculated with these isolates were sown in the field under optimum fertilization (NPK @ 150-75-50 kg ha-1). Inoculation with rhizobacteria showed an increase in grain yields of cv. Inqlab and LU 26S by upto 15.3% and 18.5%, respectively, as compared to uninoculated control. Inoculation with rhizobacteria also significantly increased the number of tillers, straw weight and lOoo-grain weight in both cultivars. Plant height was increased only in case of wheat cv. LU 26S.

GENETIC ANALYSIS OF GLYCINE MAX (L) MERRILL IN SELECTED SOWING TIME
ABSTRACT:
Glycine max (L) Merrill genotypes (Bossier, Hampton, Improved Pelican and Clark-63) were planted at 15 days interval (1st June, 15th June, 1st July, 15th July, 1st August and 15th August) at Agricultural Research Institute, Tando Jam during summer, 1993. Seed yield and yield components varied significantly (P<0.0I) due to change in sowing time and genotype. All genotypes yielded more when planted on 1st June, while decreased for each delay in planting beyond 1st June. Among genotypes Bossier yielded more over rest of the genotypes tested. Genetic analysis depicted that plant height and seed yield/plant had greater genetic advance, whereas heritability was more in plant height, seed yield/plant, branches/plant, seed index, effective pod filling period and pods/plant. Correlation of yield was significant and positive with plant height, branches/plant, nodes/plant, pods/plant, seeds/pod, and seed index. Flowering days exhibited significant and positive association with effective pod filling period. Plant height had positive and significant relationship with nodes/plaut and pods/plant. The correlation of branches/plant was positive and significant with nodes/plant, seeds/pod and seed index. Nodes/plant displayed positjve and significant correlation with pods/plant, while pods/plant depicted positive and significam association with seeds /pod and seed index whereas seeds/pod had positive and significam association with seed index.  The path coefficient analysis reveals that pods/plant, plant height and seed index had high positive direct effect on yield, while maturity days displayed high negative direct effect on yield. The multiple regression analysis suggested that pods/plant and seed index contributed significantly towards yield and could be used for future plant breeding programme of soybean.

CYTOLOGICAL STUDIES IN GlRARDINIA DIVERSIFOLIA (LINK) FRIIS
ABSTRACT:
Karyomorphological and micromorphological observations of different collections of the species Girardinia diversifolia show enough evidences to the existence of 2 or more ecotypes in the species.

Population structure, intraspecific competition and phasic development of Urochondra setulosa (Trin.) CE Hubb., a coastal halophytic grass of Pakistan
ABSTRACT:
The population structure, intraspecific competition and phasic development of growth in a population of Urochondra setulosa (Trin.) C.E. Hubb., in a dry salt marsh of Hawkes Bay, Karachi, Pakistan, are described. Density and cover values averaged 26000 plants/ha and 1951 sq. m /ha, respectively. Size class distribution was asymmetrical (X-2 = 37.62, p < 0.001) as 84.8% of the population concentrated in initial classes of plants smaller than 50 cm crown diameter. The crown size data fined best (P < 0.001) to the negative power/ logarithmic equation indicating decreasing rate of mortality with age. Drawn to scale, crown outline diagrams indicated that when a hummock reaches to a critical size of around 60 cm in diameter begins to undergo degeneration and consequent hollowing in crown develops which increases with age. Among various developmental phases, mature hummocks dominated (40%) the frequency distribution, followed by building ones (23%). The frequency of seedlings + seedlings intergrading to pioneer was more or less equal to the frequency of degenerate and eroded phases. The phenomenon of phasic development is cyclic in time though quite incoherent in space. The spatial pattern of the population was contagious as determined through rest of fitness of Poisson series and the magnitude of variance mean quotient (2.58). Bivariate Simple Linear Correlation analysis for multiple nearest neighbours measurements indicated significant competitive influence of reference plants extending upto the third neighbour only. Multivariate Canonical Correlation Analysis (CANCOR), however,indicated intense competition only between the reference plant and the second and third nearest neighbours. The first nearest neighbour appeared to exhibit substantially lower competitive interaction with reference plant. The results are discussed in view of population structure, pattern and the biological characteristics.

COMPETITIVE SUPERIORITY OF KOCHIA INDICA OVER LEPTOCHLOA FUSCA (KALLAR GRASS) UNDER VARYING LEVELS OF SOIL MOISTURE AND SALINITY
ABSTRACT:
Kallar grass [Leptochloa fusca (L) Kunth] and Kochia indica Wight were grown in mono-cultures and mixed-cultures under different soil salinity and water conditions. K. indica suppressed growth of kallar grass in all salinity and watering treatments; the reduction in biomass yield of the latter species was more pronounced in low watering treatment at both salinity levels. In contrast, K. indica gave increased yield when intercropped with kallar grass as compared to that in mono-cultures suggesting its competitive superiority. Nutrient (N ,P,K, Ca and Na) concentrations in shoots of a species grown in mono- and mixed-cultures under a particular treatment were similar. However, the total uptake of nutrients differed significantly and K. indica removed proportionately higher amounts of nutrients when grown in mixed-cultures compared to corresponding mono-cultures. The significance of competition by K. indica is discussed with regard to its invasion and spread in kallar grass stands.

SALINITY STRESS AND THE SENESCENCE PROCESS IN WHEAT (TRITICUM AESTIVUM L.)
ABSTRACT:
Salinity/Water stress commonly cause leaf yellowing due to changes in chlorophyll, reduction in endogenous cytokinins as well as an enhancement in abscisic acid (AbA) contents. Since cytokinin (CK) and abscisic acid (AbA) levels are known to differentially influence the senescence process, their effect(s) on chlorophyll contents of salinity stressed wheat (Triticum aestvium L.) seedlings showed that chlorophyll degradation was reduced by CK, benzylamino purine, BAP, but not by other treatments.

USE OF SALINE/SODIC WATER FOR IRRIGATION
ABSTRACT:
Experiments were undertaken to see the prospects of using saline/sodic water for irrigation. The brackish water was amended with biological ameliorants like sesbania, pressmud or poultry manure or used with good quality canal water in blended or cyclic modes. All the organic manures were almost equally effective in sustaining the yield. Cyclic use of canal and brackish water showed better results than the blend use. These studies suggested a possibility for using saline/sodic water for irrigating crops under specified management conditions.

THE POTENTIAL OF USING K/Na RATIO AS INDEX OF SALINITY TOLERANCE IN TOMATO
ABSTRACT:
The effects of adding K, P and Ca to saline nutrient solutions on K/Na ratio and salinity tolerance in tomato (Lycopersicon esculentum Mill) in five tomato cultivars viz., Tropic, Marikit, Montecarlo, Strain B and Pearson was studied. Addition of K, K+P and K+P+Ca to saline nutrient solutions significantly increased K/Na ratios in the leaf, stem and root as well as fruit yield by 25-35 %, whereas addition of Palone significantly reduced K/Na ratio in the stem but not in the leaf and root with a increase in fruit yield by 9%. Two types of physiological mechanism conferring salinity tolerance to tomato cultivars based on their respective K/Na ratios were detected where Marikit exhibited a typical halophytic characteristic while Tropic, Montecarlo, Strain B and Pearson showed typical glycophytic response, reaction

NITROGEN LOSSES FROM TOPS OF THREE RICE VARIETIES GROWN IN NUTRIENT CULTURE SOLUTION
ABSTRACT:
During the growth of rice crop upto 7-54% of fertilizer N is generally lost from soil plant system. Using 15N labelling technique, the balance of vegetative N between anthesis and maturity in 3 rice cultivars showed a loss of 7-21 % from foliar parts. Grain yield of the plants was dependent on the efficiency of plants to utilize vegetative N assimilated before anthesis, a factor that plays a significant role in N fenilizer economy of crop plants.

GROWTH RESPONSE OF VIGNA AMBACENSIS L. I SEEDLING TO THE INTERACTION BETWEEN NITROGEN SOURCE AND SALT STRESS
ABSTRACT:
Vigna ambacensis plants grown hydroponically in a Hoagland nutrient solution with either nitrate or ammonia as a source of nitrogen and NaCI a 0,40, 80 and 160 mM concentrations showed reduction in all growth parameters where ammonia was used as compared to nitrate as a nitrogen source. Salt decreased the growth of plants. Plants grown in nitrate were more salt tolerant as compared to ammonia especially at 80 and 160 roM NaCilevel. High salinity conditions reduced calcium and potassium contents in shots with a increase in sodium which was higher (80 m µl) in NH+4-N as compared with NO-1 3-N source.

STUDIES ON WATER SOLUBLE SUGAR AND SUGAR ALCOHOL IN CULTIVARS AND WILD FORMS OF LAUROCERASUS OFFICINALIS ROEM.
ABSTRACT:
Water soluble sugar and sugar alcohol composition in fruits of Laurocerasus officinalis cvs. Oxygemmis, Globigemmis and wild form of L. officinalis Roem., have been examined. Gas chromatography-mass spectrometry studies exhibited that the main sugars in L. officinalis and related cultivars are fructose, glucose and sorbitol and sorbitol and mannitol as sugar alcohols. Fructose, glucose and sorbitol were in significantly higher levels in cultivars and the wild form with highest value 74.4% of dry weight of total water soluble sugar in Oxygemmis and the highest level of sugar alcohol (42.6%) in the wild form with least in Angustifolia (19.9% of dry weight).

USE OF NET PHOTOSYNTHESIS AND WATER-USEEFFICIENCY IN BREEDING WHEAT FOR DROUGHT RESISTANCE
ABSTRACT:
A series of experiments were conducted in pot and lysimeter conditions to evaluate net photosynthesis and water-use-efficiency as breeding criteria for drought resistance. Six drought resistant and 6 drought susceptible genotypes were used. Net photosynthesis decreased under drought which was caused mainly by non stomatal factors. Genotypes with the same stomatal conductance had different net photosynthesis under suggesting that genotypes with high water-use-efficiency can be tailored. Measurement of net photosynthesis and water-use-efficiency can thus be used as breeding criteria for drought resistance.

EFFECT OF CENTESIMAL POTENCIES OFPYROGENIUM ON THE GROWTH AND MITOTIC INDEX OF ALLIUM CEPA ROOTS
ABSTRACT:
In homoeopathic system of medicine, the use of small ,doses of potentised substances by succession or trituration and dilution excites the curative force of the substances. When substances are diluted beyond 10-24, the original substances do not exist in the solution, still the biological activity of these substances could be demonstrated at much higher dilutions (Boyd, 1954; Khan et al., 1991). Effect of homoeopathic remedies on the growth of fungi (Kumar & Kumar, 1980), wheat coleoptiles (Khan et al., 1991) and young wheat seedlings (Jones & Jenkins, 1981) have shown promising results. Information on the effect of homoeopathic remedies on cell division seems to be lacking. The present report describes the effect of Pyrogenium potencies on cytological changes and root growth in the meristem of Allium cepa.

EFFECT OF SEAWATER AND NACL SALINITY ON THE IN VITRO GERMINATION OF POLLEN AND TUBE GROWTH OF ATHARANTHUS ROSEUS (L) G. DON.
ABSTRACT:
Gradual and shock treatments of NaCI salinity to wheat (Abdullah et al., 1978) and cotton plant (Abdullah & Ahmed, 1986) are reported to decrease the viability and germination of pollen grain. Sharma et al., (1985) also studied the pollen sterility in two varieties of grapes under different levels of soil salinity and found that increase in salinity from 2 to 8 mmhos/cm decreased the percent viability of pollens by upto 50%. Similarly, an increased spikelet sterility was also found by Murty & Rao (1968) in rice grown under saline conditions. Akbar et al., (1972) are of the opinion that sterility in rice panicles is due to some physiological disorders. The present study describes the in vitro effect of seawater and NaCI salinities on germination of pollen and tube growth of Catharanthus roseus (L) G. Don.

SOME OBSERVATIONS ON SEED GERMINATION OF KALLAR GRASS (LEPTOCHLOA FUSCA)
ABSTRACT:
Extensive studies have been conducted on Leptochloa fusca (L.) Kunth (kallar grass) regarding its salinity/sodicity tolerance, nutrition and productivity on saline lands (Malik et al., 1986). This grass easily propagates from root-stock and stem cuttings, thus information regarding its seed production and germination is scanty in the literature. Sinha et al. (1982) reported that germination of kallar grass seeds was adversely affected by osmotic tension but not by alkalinity; the viability of seeds used was very low (ca. 20%), and suggested the need for improving seed fertility/ viability of this promising species. The present paper reports some observations on germination of kallar grass seeds.

DETECTION OF ALTERNARIA PADWICKII (GANGULY) M.B. ELLIS, THE CAUSE OF STACKBURN DISEASES OF RICE
ABSTRACT:
Alternaria padwickii (Ganguly) M.B. Ellis (Syn., Trichoconis padwickii Ganguly) is an important seed-borne fungus which causes stackbum disease of rice (Noble & Richardson, 1968). The fungus occurs widely in the rice-growing countries of the world (Ou, 1985; Khair et al., 1988; Rodriguez et al., 1988; Shetty & Shetty, 1992). A. padwickii has also been found widely distributed as a common seed-borne fungus in different rice cultivars in Pakistan (Kamal & Moghal, 1968; Khan et al., 1974). Using blotter and agar plate methods, it has been usually difficult to detect and isolate T. padwickii in pure culture due to the growth of other seedbome fungi such as Pyricularia oryzae, Drechslera oryzae and species of Curvularia, Drechslera and Fusarium on rice seeds (Neergaard, 1977; Khan et al., 1988). A comparative study of various methods was therefore, carried out to find more suitable method by which A. padwickii could be detected and isolated in pure culture from rice seeds