Male parent effects on stigma receptivity and seed set of sorghum A‐lines under chilling field temperatures

Abstract

With 3 tables Abstract Sorghum hybrid seed production involves restorer (R) and maintainer (B) lines as pollen donors. In the Mexican Highlands, R‐lines produce more viable pollen than B‐lines. The influence of this characteristic on stigma receptivity and seed set (seeds/flowers) of A‐lines is unknown. Six pairs of A/B lines and four R‐lines were sown. In the A‐lines, length of stigma, style and ovary, stigma receptivity and seed set were registered. In the B‐ and R‐lines, pollen traits (production, diameter and viability) were measured. Crosses A × R were made, and the A × B isogenic crosses served as controls. There were differences (P ≤ 0.05) among genotypes for all variables. Stigma receptivity traits averaged over the A × R crosses were lower than those of the A × B crosses. Seed production traits of the A‐lines varied depending upon the R‐line crossed to, but the highest seed set was 0.37. Pollen characteristics of the B‐ or R‐lines did not correlate with stigma receptivity and neither with seed production nor with seed set of the A‐lines.