Identification of superior transgressive segregants in F2 and F3 populations of wheat (Triticum aestivum L.) for yield and its contributing traits

An experiment was carried out in timely sown condition during Rabi, 2018-20 to study the genetic variability, correlation, heritability and expected genetic advance for 13 traits in F2 and F3 populations of two wheat crosses and consequently identify superior transgressive segregants. The experimental material consisted of an F2 population of two crosses K 0307 × LOK 1 (cross 1) and HD 2733 × HUW 234 (cross 2) evaluated in an unreplicated trial and seeds of each identified transgressive segregants in F2 generation was forwarded to F3 generation for its evaluation and further sorting the superior segregants to be carry forwarded. The identified transgressive segregants exhibited a wide range of variation for all the traits except for spike length, indicating the presence of enough genetic variability in the material under study. The phenotypic coefficients of variation (PCV) values were higher than genotypic coefficients of variation (GCV) values for most of the traits studied. Estimates of genetic parameters, PCV and GCV in K 0307 × LOK 1 was highest for spikelets per spike and lowest for days to 50% flowering and days to maturity in both F2 and F3. While, highest for yield per plant and lowest for days to 50% flowering and days to maturity in HD 2733 × HUW 234. High heritability coupled with high genetic advance was recorded for spikelets per spike, test weight in a cross 1, in both F2 and F3. Similarly in cross 2, high heritability coupled with high genetic advance was recorded for grain filling days and yield per plant. Correlation analysis suggested that yield had a positive and significant relationship with test weight, grain per spike, and spikelets per spike for the F3 families of transgressive segregants of the cross 1. In cross 2, test weight, grain per spike, number of effective tillers, spikelets per spike, peduncle length, days to 50% flowering, and plant height had a positive and significant relationship with yield.