Muhammad Ahsanul Haq

Triple test cross analysis for some morphological traits in mungbean (Vigna radiata (L.) Wilczek)

Thirty progenies of mungbean were produced by crossing 10 true-breeding genotypes with three testers (NM 92, 6601, and their F1) in a Triple Test cross (TTC) fashion and evaluated with parents in the kharif (July-October) and spring/summer (March-June) seasons. The data on parents and F1s were analysed for pod clusters on main stem, pod clusters on branches, node of the first peduncle, nodes on main stem and average internode length to detect epistasis and estimate additive and dominance components of genetic variation. Epistasis was observed for node of the first peduncle and nodes on main stem in the kharif season. Partitioning of total epistasis revealed that both additive × additive (i type), and additive × dominance, and dominance × dominance (j and l types) interactions were significant with prevalent influence of i type interactions on these traits. Both additive and dominance components of genetic variation were significant for all those traits not significantly influenced by epistasis in either or both seasons. The additive component was predominant for pod clusters on main stem, pod clusters on branches and average internode length in the kharif season, and for the node of the first peduncle and nodes on main stem in spring/summer season whereas dominance component was important for pod clusters on main stem, pod clusters on branches, and average internode length in spring/summer season. These results suggested that particular generation of segregating population and specific breeding method for selection might be adopted in each season for the improvement of these traits in mungbean.

Detection of epistasis, and estimation of additive and dominance components of genetic variation for synchrony in pod maturity in mungbean (Vigna radiata (L. ) Wilczek)

Abstract Genetics of days to first flowering, first pod maturity, 90% pod maturity, and duration of the period from first flower to 90% pod maturity (DDd1) and from first pod maturity to 90% pod maturity (DDd2) [degree of non-synchrony of pod maturity] were investigated in mungbean using the triple test cross (TTC) technique. Ten diverse genotypes were crossed with two true breeding testers (L1 and L2) and the F1 hybrid of the tester lines (L3). The resultant single and three-way crosses were evaluated in two seasons (kharif and spring/summer). Epistatic variation was found to be an integral part of inheritance of days to first flower in both seasons and days to first pod maturity only in kharif season. Further partitioning of total epistasis revealed that additive×additive (i type) interactions had a major role in the inheritance of these traits. In the absence of epistasis both additive and dominance genetic components were significant for days to 90% pod maturity, DDd1, and DDd2 in both seasons, and for days to first flower in spring/summer season. The additive genetic component was predominant for days to 90% pod maturity and DDd2 in both seasons and for DDd1 in spring/summer season, whereas the dominance component was important for days to first flower and DDd1 in the spring/summer season. The direction of dominance was towards early maturity of 90% pods and late maturity of the first pod. The significant additive genetic component in DDd1 and DDd2 could be exploited in later generations for developing mungbean genotypes with improved synchrony in pod maturity.

Validation of molecular markers for resistance among Pakistani chickpea germplasm to races of Fusarium oxysporum f. sp. ciceris

DNA markers in chickpea, targetting resistance genes for different races of Fusarium oxysporum f.sp. ciceris (Foc), have been identified in chickpea, but validation of these markers is essential for effective use in resistance breeding. In view of this, different simple sequence repeats (SSR) markers were analysed in Pakistani germplasm including induced mutants and some local lines. Most of the SSR markers showed good correlation with phenotypic evaluation of genotypes to different races of Foc and may be used effectively in resistance breeding, except those markers for race 3. Markers for race 3 showed deviations from phenotypic data and the reason might be that race 3 is actually Fusarium proliferatum as reported recently and resistance to this race might involve some other major resistance genes. Poor correlation of markers with foc-3 on LG2 in our study and a recent report of independent segregation of foc-2 and foc-3 in near isogenic lines suggested that linkage distances among different resistance genes need further investigation. Moreover three Pakistani mutant lines (97477, CM444/92 and CM368/93) depicted high levels of resistance to Foc races and can be deployed as a valuable source in resistance breeding programmes.

Evaluation of twenty four new Gossypium hirsutum strains for growth, yield, fibre quality and ClCuV resistance under environment of Punjab, Pakistan

Twenty four new strains were tested for their yield, quality and Leaf Curl Virus (ClCuV) resistance. NIAB-111/S, NIAB-98 and NIAB-999 were significantly high fruit bearing varieties at 90 days completing 59.54, 48.26 and 46.00% fruiting respectively. Seed cotton yield of VH-142 was highest with 5417 kgha−1 and 52 per plant boll bearing, DNH-57 and NIAB-999 remained second and third with 5234 and 5095 kg ha−1 seed cotton yield, respectively. BH-160 and CRIS-467 were found to be second and third highest boll bearing varieties with 50.97 and 40.20 per plant average bolls respectively. Plant height in CRIS-467, MNH-642 and SLH-224 was significantly higher in comparison to other varieties.NIAB-98, CIM-499 and CIM-506 were found short stature varieties in comparison with other but out of these NIAB-98 and CIM-506 were in high yielding position and CIM-499 was found medium yielder variety. GOT% of MNH-642 remained highest having value of 45.00%. While GOT%. of NIBGE-1, CRIS-168 and CRIS-467 was at lowest position with 35.73, 35.89 and 36.62% respectively. NIAB-111, CIM-499 and BH-160 were at first position in terms of fibre fineness with micronaire values 3.98, 4.00 and 4.07 ìg/inch having fibre length 28.53, 31.38 and 30.23 mm respectively. Out of 26 varieties, 16 varieties resulted maturity index in the range of 85.03% and 90.30% with highest maturity index in case of NIBGE-1 (i.e. 90.30%) followed by NIAB-999 and MNH-642 with 89.55 and 85.5% respectively.CRIS-168, CRIS-468 and CRIS-467 were found viral susceptible.