POLLINATION AND DEVELOPMENT OF THE RECEPTIVE STIGMA IN PECAN, CARYA ILLINOENSIS
Pistillate flowers were examined in pecan, Carya illinoensis, to determine the developmental characteristics of the stigmatic surface from 7 days prior to receptivity to about 2 days post pollination. Fresh and fixed tissues were examined using histochemistry, light, scanning (SEM), and transmission (TEM) electron microscopy. The pecan stigma is of the dry type. Receptive surface cells are highly vacuolate, and have rounded basally attached papillae. An irregularly patterned surface exudate becomes evident about 3 days prior to receptivity, which stains positively for carbohydrates, lipids and cutin. Pollenstigma interactions were followed using controlled pollinations. Pollen becomes rounded and hydrated by 1 hr after pollination. Pollen tube emergence is visible within 3 hr. Collapse of stigmatic papillae is associated with pollination.
Wetzstein, Hazel Y. (1989). POLLINATION AND DEVELOPMENT OF THE RECEPTIVE STIGMA IN PECAN, CARYA ILLINOENSIS. Acta Hortic. 240, 193-196