Pollen-Tube Growth in Intergeneric Pollinations on Datura Stramonium

Abstract

Some of the barriers connected with pollen germination and with pollen-tube growth have been studied on stigmas and styles of D. stramonium. The pollens of members of the Solanaceae germinated more successfully than those of other families but pollen germination is not determined exclusively by taxonomic relationships. On the average, the Solanaceae showed faster pollen-tube growth than members of other families. The use of tetraploid styles increased slightly the speed of the pollen tubes and decreased the % of bursting pollen tubes, especially in tomato, thereby increasing the chances for the tubes to reach the ovary. Attempts to shorten the distance from the stigma to the ovary induced the pollen tubes to approach closer to the ovary, but in no case did they enter it.