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

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