濒危植物迁地保护与再引种研究组知识库

Occurrence of secondary pollen presentation (SPP) is evidenced for Duperrea pavettifolia. For this, self-pollen was presented on the stigma and reduced fertilization was observed in this case. The receptive area located in the furrow of the stigma becomes receptive from the third day of elongation growth. Fruit set upon hand pollination with pollen from other individuals was significantly higher than the results of selfed, bagged, emasculated and control treatments. However there was no difference in pollen tube growth rate between selfed and crossed pollen on a receptive stigma. Hawkmoths and butterflies were effective pollinators for D. pavettifolia, but the visiting frequencies were very low. Stingless bees removed pollen from the unreceptive stigma which had no contribution to reproductive success. High level of outcrossing in D. pavettifolia was demonstrated by molecular analyses using the simple sequence repeats (SSR) method. Although the wild populations of D. pavettifolia are small and with fragmented distribution, the genetic diversity of seedlings was high, with fluctuations among years. Our results indicated that protandry and the visitation of stingless bees reduced the amount of self-pollen on the still unreceptive stigma and self-incompatibility prevented fertilization by un-removed self-pollen.