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

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.

Identification of pre-fertilization reproductive barriers and the underlying cytological mechanism in crosses among three petal-types of Jasminum sambac and their relevance to phylogenetic relationships

“…Pistil receptivity is an important determinant of successful pollination and fertilization in seed plants. Poor pistil receptivity is one of the main factors responsible for low seed output in many crosses, including those involving chrysanthemum, sorghum, and lotus [ 9 , 15 , 29 ]. Our results revealed significant differences in pistil receptivity among the three jasmine petal-types and the four developmental stages.…”

Factors influencing fecundity in experimental crosses of water lotus (Nelumbo nucifera Gaertn.) cultivars

“…It is often characterized by inhibition of pollen germination and pollen tube growth, and abnormal growth of pollen tubes [ 13 , 17 , 26 , 27 ]. For example, low stigma receptivity is considered to be one cause of low seed set in some sorghum crosses [ 28 ]. More recently, in a study of the factors that affect seed set in several chrysanthemum crosses, we found that a low number of germinated pollen grains, and the abnormal growth of most pollen tubes, were the main causes of the failure of the cross between D. grandiflorum ‘Yuhuaxingchen’ and D. nankingense [ 13 ].…”

Rate of crop‐weed hybridization in Sorghum bicolor × Sorghum halepense is influenced by genetic background, pollen load, and the environment

“…The differences between these parental lines imply a genetic effect. A myriad of factors could cause these differences, ranging from floral structure, duration of stigma receptivity, ovule viability, and the frequency of unreduced or 2n gametes (Cisneros‐López et al, 2012 ; Moran et al, 2003 ; Nguyen et al, 2013 ). For instance, Tx623 consistently had high outcrossing frequencies, and it is known to have a longer duration of stigma receptivity (Moran et al, 2003 ).…”