Gene action for yield and related traits in soybean Glycine max L Merrill and development of interspecific hybrids involving wild species

Abstract

newlineThe present investigation entitled Gene action for yield and related traits in soybean [Glycine max (L.) Merrill] and development of interspecific hybrids involving wild species was carried out at the Experimental Farm of the Department of Crop Improvement, CSK HPKV, Palampur to gather information on genetic architecture for seed yield and component traits in soybean and to introgress desirable genes from wild species to cultivated ones. The experimental material comprised of 54 triple test cross progenies derived by mating 18 lines with three testers, namely, Hara Soya (L1), Him Soya (L2) and their F1 (L3). This genetic material was evaluated in a randomized complete block design with three replications during kharif 2013. Epistasis was found to be an integral part of genetic variation for majority of the traits. Epistatic interaction for many traits was j+land#8223; type except days to 50% flowering, days to 75% maturity, reproductive phase, petiole length, seed per pod, harvest index and 100 seed weight, whereas plant height, internode length, pods per plant and biological yield per plant carried iand#8223; type epistasis alongwith j+land#8223; type. Additive component (D) was more pronounced than dominance component (H) for most of the traits. Both additive and dominance components were of almost equal magnitude for pod length indicating the importance of both additive and dominance type of gene action, whereas partial degree of dominance was noticed for majority of traits. The kind of genetic variance revealed from triple test cross can be exploited by intermating selected individuals in early segregating generations with delayed selection in later generations, diallel selective mating/ biparental mating or recurrent selection followed by pedigree method to exploit both additive and non-additive components alongwith epistasis. Lines Bragg, Shivalik and P9-2-2 were found to be good general combiners for most of the traits. The cross combinations, Bragg x Hara Soya, PK-472 x Him Soya, DS-1213 x Hara Soya, H-330 x Hara Soya and H-330 x Him soya showed high per se performance, SCA effects, heterobeltiosis and economic heterosis for seed yield per plant and were rated as potential crosses for further improvement. Cross H-330 x Him Soya showed resistance against brown spot and bacterial pustule diseases. The interspecific hybrids developed involving Glycine max x G. soja, were true to type based on confirmation at the morphological, molecular and cytological level. Sufficient variability was found for all the traits studied in wide hybrids. Seed yield per plant showed significantly positive correlation with reproductive phase, pods per plant, pod length, petiole length, harvest index and 100-seed weight.