Cross Pollination Studies with Male Sterile Wheats of Three Cytoplasms, Seed Size on F1 Plants, and Seed and Anther Size of 45 Pollinators¹

Abstract

Forty‐five pollinators, including all market classes of wheat, were used to pollinate male sterile plants of three cytoplasms derived from Triticum timopheevi Zhuk., Aegilops caudata L., and Aegilops ovata L. Seed set ranged from 2 to 61% in 1964 and from 2 to 28% in 1965. The correlations between seed set on varieties for the two seasons were statistically significant but low. No relationship of seed set with any weather factor was evident. Pollinators varied significantly in anther length and width. Anthers of soft red winter wheats were longer and wider than those of other market classes. Weight of F 1 seeds set on male sterile plants of all cytoplasms were larger and more angular and weighed more than pollinators. However, the influence of low seed set on size of F 1 seed could not be separated from zenia effects. Seed set on fertile pollinators ranged from 95 to as low as 70% on lateral florets and 49% when all florets were considered.