Self-compatibility in six new <I>Rosa hybrida</I> cultivars

Abstract

The self-pollinated styles in six new rose cultivars were investigated by measuring pollen viability in vitro and in vivo,observing fruit set ratio and average seed numbers and fluorescence microscopic observation of pollen germination and pollen tube growth.Results showed pollen germination rate in vitro were consistent with that in vivo.The pollen germination rate of Yunfen cultivar were(33.34±1.70)%,(31.56±1.63)% in vitro and in vivo respectively.The fruit set ratio of Mitang cultivar after self pollination was 60.0% which was the highest,followed by Yunfen cultivar which was 39.24% and Yunyan cultivar showed no fruit set.The average seed numbers of all cultivars were low with Yunfen cultivar shown the highest number which was only 11.The pollen of self-compatibility cultivars began to germinate 3 h after self-pollination and the pollen tube could grow normally.The pollen tube extended into the middle of style 24 h after self pollination and passed through the base of style 48 h after self pollination and finally entered into the ovary.But the tubes of self-incompatibility cultivars stopped growing 24 h after pollination and pollen tubes suffered from deformation before ceased to grow.The results of microscopic observation were agreeable with the fruit set ratio which suggest that Yunfen,Yunmei,Mitang and Miyue showed self-compatibility while Yunyan and Fenzhuang showed self-incompatibility.