Conservation of Rare and Endangered Species Manglietia longipedunculata (Magnoliaceae)

摘要

Guangdong, Huizhou 516876, PR China. The conservation of rare and endangered species Manglietia longipedunculata was studied through field investigation and pollination biological experiments in 2008. The results is as follows: (1) Only one population of M. longipedunculata was found in Mount Nankunshan, and only 11 mature individuals were found in approximately 100 km2 around neighboring area; (2) The mature individuals of M. longipedunculata are in the upper layer of trees, associated with some species of Magnoliaceae, Fagaceae, Lauraceae, and Theaceae, etc. No seedlings ofM longipedunculata were found under the mature individuals; (3) Flowers of the whole population of M. longipedunculata totally lasted 30 days. From the beginning of perianth dehiscing to all tepals wilting, a single flower lasted 4 days; (4) According to the test with MTT method, the fresh pollen viability of M longipedunculata was 79.36%. Two days later, the pollen viability decreased to 56.04%; (5)The test with MTT method shows that M. longipedunculata is protogynous. The stigma receptivity was the strongest in the preflowering period (the day before bloomming), but only lasted one day when the first whorl tepals dehisced and opened (the first day of flowering period); (6) The major pollinators were beetles, which belong to inefficient visitors because of their low movement ability; (7) The artificial pollination experiments showed that the mating system of M. longipedunculata belonged to cross-pollination, including geitonogamy and xenogamy. Proterogyny, short period of stigma receptivity and lack of efficient pollinators were the main endangering causes ofM longipedunculata.