Combining ability of soybean (Glycine max) for low phosphorus tolerance on acidic soils of Western Ethiopia

Abstract

Determining the gene actions governing the inheritance of traits of interest has paramount importance in designing a breeding approach to improve the progeny populations. This study was undertaken to determine the combining ability of nine selected parental lines in the F2/F3 segregating populations for low P tolerance. The experiment was laid out in an alpha lattice design in two locations, that is Mettu and Assossa of Western Ethiopia that are characterized by soils with low P and pH. General combining ability (GCA) effects were highly significant for grain yield, pod length, days to maturity and plant height, while specific combining ability (SCA) effects were highly significant for grain yield, 100‐seed weight, pod length and plant height. The parent Hardee‐1 was identified as the best general combiner for yield, number of seeds per pod, pod length, plant height and pod number. The results suggest that additive gene action was important for several of the studied traits, implied by significant GCA effect, which might indicate selection for these traits could be effective in later segregating generations.

On the Importance of Soybean Seed P for Shoot P Uptake before Anthesis

“…[8] assumed that heavier seeds with higher seed P content could be considered as an adaptation trait developed by plants in response to low soil P phytoavailability. This hypothesis is confirmed by recent findings indicating genetic associations between soybean seed size and P efficiency in low-P environments [9,10]. In contrast to higher P reserves present in larger seeds, correlations between soybean seed size and other characters such as grain yield, seed protein, or seed carbohydrate content are generally not consistent but depend on the genetic population investigated, as well as on specific environmental conditions.…”