INHERITANCE OF PHOTOPERIODIC HEADING RESPONSE IN WINTER AND SPRING CULTIVARS OF BREAD WHEAT

Abstract

Populations from crosses between two winter wheat (Triticum aestivum L. em. Thell.) parents, Lancer and Warrior, which were sensitive to photoperiod, and Sonora 64, a photoperiod-insensitive spring wheat, were studied under a 10-h photoperiod. F 2 distributions supported by F 3 data demonstrated a two-gene inheritance system with dominant epistasis for insensitivity. The F 2 distributions fit the hypothesis of a 12 early:3 late:1 very late ratio, where early heading in short days was associated with photoperiod insensitivity. Minor factors also appeared to affect the earliness of heading.