POLLEN TUBE GROWTH IN MANDARIN

Abstract

Pollen tube growth was studied in cvs. Monica, Reyna, Dancy, and Satsuma mandarin (Citrus reticulata unshiu Marc). Pollen tubes were stained with lacmoid and observed with a white light microscope. Lacmoid stained the callose brilliant blue. Pollen grains deposited on the stigma varied from 367 to 4170 among the four cultivars. Pollen germination, however, varied from 1 to 4 %, probably having effects on the ovule fertilization. The pollen load on the stigma of ‘Satsuma,’ both under of open and self-pollination conditions, was low probably due to male sterility. In compatible pollinations the pollen tubes reached the ovary in only 2 days, while in self-pollinated ‘Monica’ and ‘Satsuma’ pollen tubes were not observed in the locules after 8 d. According to the development and number of pollen tubes, cvs. Reyna, Dancy and Satsuma could be good pollenizers for cv. Monica.