THE STATUS OF 1B/1R TRANSLOCATION CHROMOSOME IN SOME RELEASED WHEAT VARIETIES AND THE 1989 CANDIDATE VARIETIES OF PAKISTAN
ABSTRACT:
The homozygous chromosome translocation, 1B/1R 1B/1R, involving the short arm of Secale cereal chromosome 1 (1RS) and the long arm of Triticum aestivum chromosome 1B (1BL) has been a potent genetic source of disease resistances in wheat varieties released globally. The genes located on 1RS have been associated with leaf –rust (Lr26), stem-rust (Sr31) , stripe- rust (Yr9) and powdery mildew(Pm8). In the 1988-89 national uniform wheat yield trials (NUWYT) of the 38 entries including three checks; one for each of the normal, short- duration and rainfed categories; there were 25 entries with the 1B/1R translocation. The Pak-81 variety was 1B/1R homozygous. Some of the recent wheat varietal releases in Pakistan after 1980 were also analyzed, and 7 varieties of the 11 checked possessed the 1B/1R homozygous translocation. This paper also discusses the constraints that may be prevalent when large chromosome segments are involved in transfersfrom a common genetic base.

YIELD COMPONENT ANALYSIS IN FIFTEEN LABLAB BEAN CULTIVARS
ABSTRACT:
Genetic variability and correlation analysis for yield and its components were studied in 15 strains of lablab bean (Lablab purpureous L.) having diverse origin at National Agricultural Research Centre, Islamabad. Highly significant differences were observed for all the characters indicating a high degree of variability in the material. Genotypic coefficients of variability were generally lower than phenotypic coefficients of variability indicating the influence

EFFECT OF ABSCISIC ACID ON EXUDATE OSMOLARITY AND PROTON FLUX IN EXCISED MAIZE ROOTS
ABSTRACT:
The effect of abscisic acid (ABA) on the xylem exudate osmolarity and proton flux in in excised roots of maize (Zea mays L.) cv Anjou 210 was determined It was observed that ABA does not alter the exudate osmolarity until 24 h from excision, but beyond this, there was a little drop in the exudate osmolarity. ABA increased potassium flux (Qoix) leaving the proton flux (Qion) little or unaffected. The noticeable point, however , was the increased chloride flux(Qoia) by ABA , and differential response of root segments to create a proton gradient. These data suggests that ABA has an additive effect on the proton pump in excised maize root cells. This happened to maintain primary energy requiring process ‘’Qion’’ for increased K transport into the symplasm.

A FIRST RECORD OF THE GENUS COTTONIELLA BORGESEN (CERAMIALES, RHODOPHYTA) FROM LIBYA
ABSTRACT:
This is a first report of the occurance of the genus Cottoniella Borgesen from the cost of Libya. The number of pericenral cells in the specimens are 4-6 and not only 4 as in most species of the genus. The lateral pericentral cell is first formed and the development of monosiphonous filaments is endogenous as wel as exogenous. The Libyan specimen is therefore designated as Cottoniella libyensis Nizam & Godeh sp. nova

STAURODESMUS IN PESHAWAR VALLEY
ABSTRACT:
Four species of Staurodesmus have been described from Peshawar valley which occur in basic waters . These are new records for country.

FATTY ACID CONPOSITION OF ULVA (CHLOROPHYCEAE)
ABSTRACT:
Green seaweeds, Ulva fasciata Delile, U. indica Anand and U. lactuca Linnaeus collected from Buleji near Karachi were investigated phycochemically by gas chromatography and mass spectrometry. Saturated acids were greater than unsaturated ones.Linoleic acid was the only unsaturated acid present. U. fasciata was different in its fatty acid composition than U. indica and U. lactua.

EFFICACY OF THREE DETECTION TECHNIQUES FOR THE ASSESMENT OF SEED MYCOFLORA OF CARROT IN SINDH
ABSTRACT:
Using blotter , deep freezing and agar plate method of ISTA, the seed borne mycoflora of five carrot cultivars from Sind were examined. The pathogen isolated were Alternaria alternate, Cladosporium cladosporioides, Fusarium moniliforme, F. oxysporum , F. emitectum, Macrophomina phaseolina, Penicilium sp., and Aspergillus candidus whereas Aspergillus flavus, A. glaucus, A. sulphureus, A. terreus, A. wentii, Chaetomium globosum, Chaetomium sp. Memnoniella echinata, Rhizopus nigrican,

PHYTOSOCIAOLOGY OF THE WATER COURSES OF QUETTA DISTRICT
ABSTRACT:
Twenty three plant communities recognized on the basis of compositional similarity were grouped into 7 steppe types which show the correlations with the edaphic factors viz., Peganum harmala steppe:-Medium Cl; Saccharrum griffithii steppe:- Mostly low HCO3 , low EC and medium organic matter: Hertia intermedia steppe:- Low to medium MWHC, Ca++ + Mg++: Artemisia maritime steppe:- Medium to high Cl; Wet steppe :- Low to medium MWHC , high CaCO3,high to medium Cl and Ca++ + Mg++. Individual communities in each steppe type also differentiated on the basis of edaphic factors. The total coverage was found to be low. Species diversity was generally high in protected areas as compared to unprotected areas.

A TECHNIQUE FOR THE DETECTION OF INTRASPECIFIC COMPETITION IN PURE PLANT POPULATIONS
ABSTRACT:

TAXONOMIC AND BIOGEOGRAPHIC NOTES ON
ABSTRACT:
A distributional survey in relation to the phytogeographical regions, recognized in Pakistan and Kahsmir , for all the 14 taxa

PHYLOGENY AND ORIGIN OF AUSTRALIAN CALANDRINIA (PORTULACACEAE)
ABSTRACT:
A possible scheme of phylogeny is presented. The possible evolutionary lines in the genus Calandrinia are discussed . It is concluded that the species of Calandrinia have originated within the Australian continent.

CHARACTERIZATION OF AGROBACTERIUM TUMEFACIENS BIOTYPES ISOLATED FROM JORDAN
ABSTRACT:
Out of 183 isolates from soil and plant tumors from different locations in Jordan , 12 pathogenic isolates of Agrobacterium tumefaciens were obtained from soil , 29 from grapevines , 6 from apple , 2 from pear and 3 from peach. Biotype I was predominant . Eighteen isolates were included in biotype III and 12 isolates in biotype II. Grapevine isolates showed their tumorigenicity mostly on grapevine , some of them were able to transform tobacco and kalanchoe cells. Peach isolates were highly virulent with a wide host range.