Biometrical Analysis of Triple Test Cross to Detect Gene Action in Bread Wheat

Abstract: This study was carried out during 2014/2015, 2015/2016 and 2016/2017 growing seasons in order to unveil the supremacy of gene action, non-allelic interaction and predict new recombinant lines following biometrical triple test cross analysis involving three testers `(P1 "Sids 12", P2 " Misr 1" and their F1) and ten lines of bread wheat grown in the experimental farm of the New Valley, Agricultural Research Station, ARC, Egypt. The parents (lines and testers) and crosses were evaluated in a randomized complete block design. The results reflected significant differences within and among triple test cross families in all studied traits, indicating the presence of high segregations. Overall epistasis was highly significant for most studied traits, indicating the important role of epistasis in the heritable control. Partitioned epistasis revealed significance and importance of (i) type (additive x additive) in the genetic control for most studied traits, indicating that selection in early segregating generations would be effective to improve the yield traits. Dominance degree estimates recorded less than one for all traits, except for plant height, confirming that these traits were influenced by additive effects as well as the role of partial dominance. Positive directional dominance was obtained for number of spikes and grain yield per plant, whereas plant height and number of kernels per spike showed negative directional dominance, but 100-kernel weight possessed ambidirectional dominance. The estimates of heritability in the narrow sense ranged from 0.09 for number of spikelets per spike to 0.86 for number of spikes per plant. Then, prediction and properties of recombinant lines were computed for number of spikes and grain yield per plant. Separation of the genetic correlation illustrated significant epistasis, additive and dominance genetic correlation between grain yield per plant and number of spikes per plant.
Publication year 2017
Pages 549 – 565
Organization Name
Author(s) from ARC
Publication Type Journal
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