Heterosis and Effect of the Rht 3 Gene on Plant Height and Its Components in Hybrid Bread Wheat with T. timopheevi Cytoplasm

The heterosis of plant height and its components of hybrid bread wheat and the effect of Rht 3 gene were investigated in this paper. The results showed that all characters of hybrids had heterosis and heterobeltiosis, but their values varied among crosses and internodes; the heterosis and heterobeltiosis of length of basal internode were larger than those of other internodes and length of spike; there were less heterosis and heterobeltiosis for all characters in the hybrids from female parents with the Rht 3 gene than those in other hybrids. The Rht 3 gene increased the effects of lengths of second and third internodes and their heterosis on plant height and changed the relationships among the components in F1 hybrid. In the combinations from Aline with the Rht 3 gene, the R Iines were much more important to determine the plant height and its components of their hybrids than A lines, and so, it was relatively easier for breeders to control these characters of hybrid vvheat.