Scanning Electron Microscopic Study on Pollination of Primula sieboldii E. Morren

Abstract

Scanning electron microscopic observation on the interaction between stigmata and pollen grains, in cross- and self-pollinated cultivars of Primula sieboldii E. Morren, has been examined. This species and its cultivars have generally a heterostylic character, namely pin form and thrum form, of which pollination have a relation to the length of stigmatic papillae and the size of pollen grains. Pollen grains on the cross-pollinated stigmata, germinated and their tubes grew and later penetrated into the stigmata, therefore the fertilization was carried out successfully. In the self-pollinated stigmata, on which pollen grains germinated and abnormally grew, but almost never penetrated. We suggest that compatibility or incompatibility depends on the genetic control.