Abstract
Twelve F1 hybrids were produced by crossing cytoplasmically male sterile and fertility restorer lines of six Japanese common wheat varieties. When compared to the better normal parental varieties, majority of the F1 hybrids showed delayed heading, increased height and spikelet number and reduced seed fertility, 1, 000-kernel weight and grain yield. However, comparison of the F1 hybrids to the parental substitution lines revealed that some hybrids could exceed the better parental lines in agronomic characters including yield, though most were inbetween of the two parents. If detrimental effects of the male sterile cytoplasm are nullified by some means, heterosis in the form of increased yield can be expected from hybrid wheat varieties.
