Self-pollination and pollen germination in Japanese morning glories (Ipomoea nil)

Abstract

Self-pollination and pollen germination in Japanese morning glories (Ipomoea nil Roth.) were investigated. Within the flower buds, anthers were situated under stigmas; 90% of these anthers became situated over stigmas as the filaments elongated during anthesis. The flowers were thus selfed with approximately 40 pollen grains adhering to the stigmatic surface; 17% of pollen germinated. The pollen to ovule ratio was 180 and there were no significant differences in seed set between flowers which were hand- pollinated with an abundance of pollen grains and those which were autonomously selfed in bags. Thus we consider the Japanese morning glories to have evolved to produce seeds primarily by selfing.