Genetic Parameters of Earliness and Other Agronomic Characters in Ten Bread Wheat Crosses

Abstract

Ten bread wheat crosses derived form five different genotypes were sown to estimate potance ratio, inbreeding depression, heritability, genetic advance and correlation coefficient, among eight earliness and agronomic characters such as days to heading, days to maturity, Grain filling period, Grain filling rate, Number of spikes/plant, Number of kernels /spike, 100-Kernel weight and Grain yield per plant. The experiment was carried out from 2009/2010 to 2011/2012 seasons at Sakha Agric. Res. Station, ARC, Egypt. The t-test of differences between parents of each cross was significant in most studied crosses. The genetic analysis showed that genetic variance among F2 plants was genetically different for all studied characters in the ten crosses. Moreover, values of potence ratios were more than unity for most studied characters in all crosses. For inbreeding depression, estimates were significant or highly significant negative for most characters in most crosses except for kernel weight which was positive for most crosses. The obtained results indicated that heritability in broad sense (h 2 b) ranged from moderate to high for most studied characters. With regard to expected genetic advance, values for most studied characters were moderate in all studied characters. Also, significant positive correlation coefficients among most studied characters in all crosses were detected. The best crosses for improving earliness characters were Gem. 9 × L. 2, Sh. 1 × L. 2 and L.2 × L.3. On the other hand, the favorable crosses for increasing yield and yield components characters were Gem. 9 × Sh. 1, Gem. 9 × L. 1 and Sh. 1 × L. 3. These crosses may be used in breeding program for developing characters under study.