Genetic behavior of some agronomic characters in three bread wheat crosses under different environmental conditions

Abstract EN

This investigation was carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Egypt during the three successive seasons,i.e., 2015/2016, 2016/2017 and 2017/2018 to study nature of gene action for yield and its components, heterosis expression, heritability and expected genetic advance under normal and water stress conditions.

Six populations model (P1, P2, F1, F2, BC1 and BC2) was used in this study for three crosses; (I) Gemmeiza 11× Giza 168, (II) Giza 171× Shandawel 1 and (III) Gemmeiza 9× Misr1.

Means of the six generations were recorded for eight characters, i.e.

number of spikes per plant, plant height, main spike length, number of spikelets per main spike, number of kernels per main spike, main spike yield, grain yield per plant and 1000- kernels weight.

Results revealed that the coincidence of sign and magnitude of heterosis and inbreeding depression was also detected for most characters in the three crosses under both conditions.

Study of generation means analysis revealed that additive, dominance and epistasic effects were involved in the inheritance of yield and its components.

Additive (a) and dominance (d) genes effects were significant for most studied characters under both conditions.

High heritability estimates in broad sense were detected for all studied characters in the three crosses under both conditions, except, main spike yield in the first cross under stress.

Narrow sense heritability estimates were found to be high for most characters under both conditions.

Moderate to high genetic advance (Δg%) was detected for all characters of the three crosses under the two environments, except, plant height for the three crosses under normal condition and first and second cross under stress condition.

The highest estimates of narrow sense heritability associated with highest genetic advance for most of the studied characters in most of crosses under both conditions indicated sufficient improvement of the variable characters.

These results indicated the possibility of practicing selection in early generations for these characters.