Outcrossing was reported to be a function of floral morphology and flowering behavior of both the A lines and the male parents (Oka and Morishima 1967). This study was carried out to evaluate the extent of variation in floral traits in some common A lines.
The experimental materials were composed of 15 male sterile (A) lines and their maintainers (B). The traits evaluated were days to 50% flowering, panicle emergence, and average period of time (in minutes) from the opening of lemma and palea of individual florets to closing of the florets. The angle of lemma and palea at peak anthesis (in degrees) was measured when the floret was fully opened. The size of the stigma (mm2) was likewise calculated. Broad-sense heritability was calculated using the method of Hanson et al (1956).