Effect of Pistillary Sap on the in vivo Pollen Tube Growth and Changes in Components of Stylar Sap by Pollination in Lilium longiflorum Thunb.

Abstract

When stigmatic sap or stylar sap collected by centrifugation was placed on the stylar canals of bisected pistils of Lilium longiflorum, or when pollen grains were pre-soaked in the stigmatic sap, growth of pollen tubes in the style was accelerated even inn self-combination.
When stylar sap collected from cross-pollinated styles was placed on the stylar canals of the bisected pistils, the growth of incompatible pollen tubes was significantly promoted more than by the placement of the sap from non- or self-pollinated styles.
Changes in constituents of the stylar sap after pollination were also examined. Protein content in the sap decreased in the upper 4/5 of the style in 24 hrs after pollination. Stylar sap eluted through Sephadex G-150 column showed two peaks of carbohydrates, i.e., a broad band of high molecular weight and a narrow band of low molecular weight. After cross-pollination, both peaks were lowered, while after self-pollination only the peak of low molecular weight was lowered.
These results suggest that the movement of stylar sap from the stylar tissue to the stylar canal is different between self- and cross-combinations, and that the inhibitory substance for the pollen tubes is absent even in self-combination, and that certain proteoglycans are related to self-incompatibility.