The progamic phase and seed formation in Armoracia rusticana

The progamic phase is a period of specific interaction between the male gametophyte and the pistil tissues and is very important for proper seed development in plants. The aims of this study were to investigate the events during the progamic phase in Armoracia rusticana, to examine a plant’s capability of sexual reproduction and to obtain vital seeds under natural conditions. There were very few pollen grains on the stigmas at anthesis stage. The incompatibility reaction between the stigma cells and pollen grains was observed by using fluorescence microscopy. A series of ovary cross‐sections revealed a high accumulation of Periodic Acid Schiff (PAS)‐positive globules in all the embryo sacs. About 33% of ovules in the ovary were fertilized, but only 3% of them were able to germinate into seedlings.