A Study of Pollen Tube Growth in Several Apricot Cultivars (Prunus Armeniaca L.)

In vitro pollen germination and also pollen tube growth dynamics in different pollination treatments under controlled temperature, humidity and photoperiodicity were studied regarding four cultivars (‘Shastomi - e - Do’, ‘Ebrahim - e - Kalajah’, ‘Sefid - e - Rezaeeieh’ and ‘Razi’) under self and under cross-pollination along with three superior genotypes (‘269’, ‘416’ and ‘464’) of apricot. Following 24, 48 and 72 hours after controlled pollination, pistils were fixed in FAA. Subsequently, pistils were rinsed several times with water, and autoclaved in a 5% sodium sulfite to be soflened. After being stained with aniline blue, pistils were examined through fluorescent microscopy. Results indicated significant differences among the studied cultivars for all the traits. The highest and lowest percentages of in vitro pollen germination were observed in cultivars ‘Sefid - e - Rezaeeieh’ and ‘Razi’ respectively. As for the number of germinated pollen grain at the stigma, results revealed significant differences regarding the interaction of cultivars and pollen source. A general decrease in the number of pollen tubes was observed at the end of the style, in a way that the lowest percentage of pollen tubes in the third part of the style was observed under self-pollination. Regarding the pollen tubes either reaching the ovary or not, the results established the self - compatibility of ‘Shastomi - e - Do’ and self - incompatibility in the case of the other studied cultivars.