Estimate of heterosis and combining ability for resistance to rust “Phakopsora Pachyrhizi” and selected agronomic traits of soybeans [Glycine max (L.) Merrill] genotypes in Ethiopia

Hunde, D.; Mohammed, W.; Bekeko, Z.; Abebe, A.

Estimate of heterosis and combining ability for resistance to rust “Phakopsora Pachyrhizi” and selected agronomic traits of soybeans [Glycine max (L.) Merrill] genotypes in Ethiopia

Autores

Editor

Springer

Descripción

A half diallel crosses were carried out using ten parental lines of soybean (G7955-C3 (Rpp3), BRS 283 (Rpp1), PI200492 (Rpp3), Hyuuga PI506764 (Rpp3), PI471904 (Rpp3), PI200487 (Rpp3)) from USA, TGX-1990-57F, TGX-1995-5F from IITA (Nigeria) and T5-EL-LD-77JM-17-H25 advanced Ethiopian lines. We investigated rust severity, sporulation levels, yields and other measured characters in soybean over a period of two planting seasons across two testing sites in Ethiopia. The analysis of variance for all of the characteristics indicated highly significant differences among parents and progenies. Additive and non-additive gene effects were most important with respect to 50% days to flowering and rust severity, while genetic dominance effects mainly controlled days to 95% physiological maturity, plant height, Number of seed per pod, number of pods per plant, and yield. The GCA effects of the parent and the SCA effects for the crosses were significant for rust severity, rust sporulation levels and for yield. Progenies derived from the crosses P3xP5, P3xP6, P3xP8, P4xP5, P4xP6, P4xP7, P5xP6, and P5xP7 had significant positive GCA and SCA effects for rust severity and yield. Favourable heterosis for grain yield (42.15) and rust severity (31.78) over the better parent and favorable hetrosis for grain yield (8.52) and rust severity (11.11) over the mid parent were obtained. Thus, there is the potential to generate superior cultivars in segregant generation of soybean for rust resistance breeding program.