ibclogo XVI International Botanical Congess


Abstract Number: 4969
Poster No. = 744


POLLEN TUBE ATTRITION IN CLARKIA UNGUICULATA


Nemeth, M. Barbara and Nancy L. Smith-Huerta, Department of Botany, Miami University, Oxford, OH 45056.


Pollen tube attrition occurs when pollen tubes decrease in number as they grow from the stigma to the base of the style. Levels of pollen tube attrition were measured in flowers of Clarkia unguiculata cross-pollinated with low, medium and high numbers of pollen grains. Stigmas and styles were collected at 48 hrs post-pollination. The number of pollen grains on the stigma and the number of pollen tubes in the upper and lower style were counted using fluorescence microscopy. Pollen tube attrition was relatively high between stigma and style, with only 47 to 64% of pollen tubes reaching the upper style. Once in the style, attrition was lower, with 76 to 90 % of pollen tubes completing growth from upper to lower style. Levels of attrition were correlated with pollen numbers on the stigma. Low pollen treatments showed lower levels of attrition, while high pollen treatments showed higher levels of attrition.


HTML-Version made 7. July 1999 by Kurt Stüber