Response to two-way selection for harvest index in two wheat (Triticum aestivum L.) crosses

Abstract

A two-way selection experiment was conducted during 1974 and 1975 with two wheat (Triticum aestivum L.) crosses with a view to measuring the direct response of harvest index and its correlated response of grain yield. In the F₂ generation, 10% selection intensity was applied for high as well as low harvest index and the selected populations were grown in the F₃ generation. The progenies selected for low harvest index in the F₂ generation gave low harvest index in F₃ plants also, while those selected for high harvest index in the F₂ generation segregated into high and medium harvest index in F₃ plants. Simple and partial correlations of plant weight and grain yield with harvest index suggested a moderate to high positive association of grain yield with harvest index in the F₃ generation. Estimates of heritability and gain from selection were high. The crosses under study provided evidence on the possible use of harvest index as a selection criterion for yield improvement in early segregating generations.