广西蜘蛛抱蛋(Aspidistra retusa)的传粉生物学研究

Pollination biology of Aspidistra retusa

关键词:  广西蜘蛛抱蛋, 蜘蛛抱蛋属, 传粉生物学, 瘿蚊, 双翅目

Key words:  Aspidistra retusa, Aspidistra Ker-Gawl., pollination biology, gall midge, Diptera

摘要:

蜘蛛抱蛋属植物的花部结构丰富多样,且常常贴地表开花,但其传粉生物学研究鲜有报道。广西蜘蛛抱蛋(Aspidistra retusa)是广西特有植物,为揭示该物种的自然传粉机制,在蜘蛛抱蛋属世界分布和分化中心的广西境内,开展了广西蜘蛛抱蛋开花物候、访花昆虫及繁育系统的野外观测研究。结果表明:广西蜘蛛抱蛋的花部结构中雄蕊高于雌蕊,但自交不亲和,为异花传粉; 双翅目瘿蚊属成虫(Cecidomyia sp., Cecidomyiidae, Diptera)为其专性传粉者,作为回报,广西蜘蛛抱蛋为瘿蚊提供理想的交配场所,同时提供大量的花粉供雌瘿蚊取食以补充生殖所需能量,并为受精卵的孵化以及幼虫的发育提供舒适的环境。该研究用实地现场观察第一手数据验证了前人有关蜘蛛抱蛋属植物瘿蚊传粉的推测,为中国蜘蛛抱蛋属植物传粉生物学研究的首次报道,然而蜘蛛抱蛋属植物花部结构极具多样性,应存在更多样的传粉方式,还有待更深入的调查研究。

Abstract:

Aspidistra Ker-Gawl.(Asparagaceae)is one of the largest genera in monocots, flowers of most Aspidistra species grow on the ground and are even buried in leaf litter, inaccessible to many potential pollinators, and pollination biology of Aspidistra has been poorly studied. Aspidistra retusa is a typical species with higher stamens than pistil in floral structure, distributed only in Guangxi, China. In order to reveal the significant pollination mechanism, we focused on its floral morphology, reproductive biology and pollinator behavior. The results indicated that A. retusais was a self-incompatible species and pollen vector was necessary for fruit set. Cecidomyia sp.(Cecidomyiidae, Diptera)served as the sole pollinator and A. retusa provided suitable mating site and abundant pollen for the adult of gall midgeand protection for the hatching of zygote and the development of larvae as rewards. This study provided the first field observation on the pollination biology of the genus Aspidistra distributed in China and verified vividly the previous speculation of gall midge pollinating for Aspidistra. However, Aspidistra plants with species diversity, there should be more pollination patterns, still need further research.