Abstract

Stigma receptivity in pigeonpea [Cajanus cajan (L.) Millsp.] was studied using 2 male-sterile lines (ICPA 2039 and ICPA 2043) under field conditions. An experiment was conducted to observe the stigma receptive period at Nanning (22°N 108°E) in Southern China. The study revealed that the stigma was receptive 48 h before flower opening and continued up 4 days after flower opening. The peak stigma receptivity was on the day of flower opening with 84 and 86% pod set after hand pollination in the male-sterile lines ICPA 2039 and ICPA 2043, respectively. This floral stage is characterized by the corolla to calyx length ratio of 2.75 ± 0.075 (ICPA 2039) and 2.60 ± 0.283 (ICPA 2043). The long time span of stigma receptivity in pigeonpea encourages insect-aided natural out-crossing. This information will help breeders to carry out hybridization activity with high success rates. Also the long receptivity may facilitate more seed yield in isolated seed production blocks.

Key words: CMS lines, pigeonpea, stigma receptivity.