Crocus sativuspollen germination and pollen tube growthin vitroand after intraspecific and interspecific pollination

摘要

The germination and tube growth of saffron (Crocus sativusL.) pollen were studiedin vitro(in liquid media) andin vivoin pistils ofCrocus sativusandCrocus thomasiiafter intraspecific and interspecific pollinations.In vitroabout 20 of the saffron pollen grains germinated, but only about 9 developed a pollen tube. Although 21 of the pollen germinated on the stigmas, most pollen tubes ceased growth in the pistil and only a low percentage (about 6 of germinated grains) reached the ovary, where few of the ovules (about 5) were penetrated. The defective germination and pollen tube growth were correlated with the occurrence of cytological abnormalities of the saffron pollen. Moreover, the ovarian transmitting tissue appeared to prevent the penetration of the ovules.