Abdul Ghafoor

Genetic relationship in Vigna mungo (L.) Hepper and V. radiata (L.) R. Wilczek based on morphological traits and SDS-PAGE

Thirty seven diverse genotypes of Vigna mungo and three of V. radiataresembling to V. mungo for seed characters were studied to determine the extent of genetic variation based on morphological characters. In addition, 4black seeded genotypes in each species and8 green seeded V. radiata genotypes were included for SDS-PAGE analysis. Seed proteins were analyzed through slab type SDS-PAGE. High variance was observed for plant height, days to flowering, days to maturity, number of branches/plant, number of pods/plant, pod length, seeds per pod,biomass yield/plant, grain yield/plant and harvest index (%) during 2 consecutive years. First four components of PCA with eigenvalues >1 contributed 78.7 and79.1% of the total variance amongst 40genotypes during 1998 and 1999. The populations with high PC1 values were expected to be high yielding characterised by earlyness, high seed weight and harvest index, all traits strictly related to reproductive phase. Four clusters of genotypes were observed during both the years and genetic diversity was in association for both the years. Based on SDS-PAGE, specific bands were suggested to be used for identifying Vigna radiatafrom mixed germplasm with Vigna mungo. The SDS-PAGE proved to be a powerful tool for differentiating Vigna radiata and Vigna mungo, whereas a low level inter-specific genetic diversity was observed and no clear differentiation was observed both for agronomic characteristics and for geographical origin.

Genetic variability in bread wheat (Triticum aestivum L.) of Pakistan based on polymorphism for high molecular weight glutenin subunits

Variation in bread wheat including pre and post green revolutions varieties of Pakistan along with landraces was investigated for high molecular weight Glutenin subunits (HMW Gs) encoded at three genes (Glu-A1, Glu-B1, Glu-D1) with SDS-PAGE. The germplasm was diverse and unique on the basis of HMW Gs compositions and out of 14 alleles detected at all the Glu-1 loci, three belonged to Glu-A1, nine to Glu-B1 and two to Glu-D1 locus. High variation was observed in the landraces and higher gene diversity was observed between the populations as compared to the gene diversity within populations, whereas a reverse pattern of gene diversity was observed when populations were pooled across the region (higher within the regions than between the regions). A lack of relationship between the HMW Gs diversity and the altitude of collection site was observed. A data base has been generated in this study which could be expanded/exploited for cultivar development or management of gene bank.

Marker assisted selection (MAS) for developing powdery mildew resistant pea cultivars

In this contribution we review the state of the art for genetic resistance to powdery mildew, caused by Erysiphe pisi, in pea (Pisum sativum L.) and potential use of marker-assisted selection (MAS) for developing disease resistant cultivars. Powdery mildew is important in many production regions worldwide and reduces yield and crop quality when present in epidemic proportions. Although genetic resistance to powdery mildew is available (er1 and er2) and has been durable since its characterization in 1969, recently a new dominant gene (Er3) has been reported in Pisum fulvum, a wild relative of pea that is different from previously reported er1 and er2. The efficacy of these genes may be at risk from the point of view of new pathotypes and pathogens. Erysiphe trifolii has been reported that was not previously known as a pathogen of pea powdery mildew. A continued search for new and diverse resistant sources remains a priority in pea breeding and special emphasis should be paid to selection of resistance that will prolong durability of existing resistance genes. Marker assisted selection is a new emerging approach for target breeding that has been intensively employed especially in cereals and has recently got popularity among legume breeders. With the advancement of genomic research, especially related to quantitative traits loci, the MAS is potentially anticipated future technique for routine plant breeding that is scarce in legumes at present. In pea, various DNA markers have been reported linked to er1, er2 and Er3 at varying distances in different mapping populations that are currently being used in breeding programs. Currently MAS of single gene is the most powerful approach and successes have been witnessed. If single marker is not close enough to the gene of interest then two flanking markers are considerably utilized to improve the correct identification that is being successfully employed in MAS for powdery mildew resistance in pea.

Study of nutritional characteristics, mineral nutrients and agro-biodiversity in black cumin ( Nigella sativa L.) genotypes from Pakistan

Nigella sativa (L.) a member of the family Ranunculaceae is being used for edible and medicinal purposes in several countries of the world. This study revealed the analysis of genetic diversity of thirty six (36) genotypes of N. sativa based on yield traits, nutritional characteristics, and mineral nutrients. Two genotypes PK - 020561 and PK - 020646 differed significantly from other 34 genotypes with respect to grain yield (P = 0.0007), biomass (P = 0.049), oil content (P = 0.001), nitrogen (P = 0.0117), calcium (P = 0.0164) and boron (P = 0.0004). These results indicated the scope of these traits for selection of genotypes. Eigen values were greater than 1 indicating the significance of principal component analysis. Five and six clusters were observed for nutritional characteristics and mineral nutrients respectively. Based on principal component analysis, yield traits contributed 86% of the variability pertained to nutritional characteristics, whereas four factors contributed 68% of the genotypes variability based on mineral nutrients. The genotype PK - 020646 produced the highest biomass, harvest index, grain yield, oil content, protein, moisture, fibre, N, Pb, Co and Mn, whereas PK - 020561 produced the highest Ca, Mg, Pb, Zn, Mn, Na and P contents. UPGMA cluster analysis based on nutritional characteristics revealed five distinct clusters with genotypes which were markedly different. Thus, all clusters were cluster 5 and cluster 1, dominating other clusters. Based on thirteen (13) mineral components, all genotypes formed six clusters, with clusters 4 and 5 having 11 and 10 genotypes. Thus, Euclidean distance among genetically distinct clusters supports different patterns of yield and mineral nutrients. The overall grouping of clusters corresponded with principal component analysis confirming the genetic variability among genotypes. These genotypes are suggested for their further application in the genetic improvement of N. sativa L, for their use as quality food to substitute Nigella cultivars currently being used. Key words : Biodiversity, black seed, cluster analyses, kalonji, physico-chemical traits, principal components’analysis.

Κ‐CN gene polymorphism in Nili‐ravi buffalo, Achai and Sahiwal cattle of Pakistan

Kappa-casein (κ-CN) is the subtype of casein protein, an important constituent of bovine milk protein. The current study was undertaken to investigate the genetic polymorphism in κ-CN gene of Nili-ravi buffalo, Achai and Sahiwal cattle of Pakistan using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) technique. The Nili-ravi buffalo was found to be monomorphic (genotype BB only) for κ-CN gene. Achai cattle were polymorphic for κ-CN (having three genotypes AA, AB and BB) with a frequency of 0.70, 0.18 and 0.12, respectively, while in Sahiwal cattle, both the genotypes AA and AB were found with genotypic frequencies of 0.92 and 0.08, respectively. The presence of genotype BB in Achai cattle is surprising as it is absent in most of the cattle breeds worldwide.