Inheritance studies for post-anthesis mobilization of assimilates in wheat under rainfed condition

Abstract

Wheat (Triticum aestivum L.) is the most widely grown crop of the world and staple food of about 35% of world
population. Photosynthate or current assimilates are the primary carbon source for grain filling, but under moisture stress
these may not be available. Hence, the stem and other plant parts reserves are an essential carbon source for grain filling
under stress conditions. Analysis of variance exhibited significant genotypic differences for all the traits under study.
Under the treated condition, genotype LLR-21 showed the highest translocation of dry matter and translocation efficiency
among parents, while LLR20 showed the highest percentage of contribution of pre-anthesis assimilates to grain. Among
crosses, cross LLR-22 x CB-42 showed the highest value for translocation of dry matter and translocation efficiency,
while Nazcozari x LLR22 showed the highest percentage for contribution to pre-anthesis assimilates. Combining ability
analysis revealed that the traits showed different behavior under stress conditions than the control condition. GCA mean
squares for the dry matter at anthesis, dry matter at maturity, translocation of dry matter and contribution of pre-anthesis
assimilates to grain was lower than SCA, suggesting the presence of a non-additive type of gene action under control
conditions. GCA mean squares for translocation of dry matter, translocation efficiency and contribution of pre-anthesis
assimilates to grain were lower, indicating the presence of non-additive gene action for these traits under-treated
conditions. The dry matter at anthesis and dry matter at maturity showed additive type of gene action under-treated
conditions