摘要
采用改良Knop′s固体培养基、原生境腐殖质土和红壤分别培养扇蕨(Neocheiropteris palmatopedate)孢子,光学显微镜及解剖镜下观察记录其孢子萌发及配子体发育过程,比较了3种培养方法对其配子体发育和有性繁殖的影响,并在此基础上探讨了扇蕨的濒危原因。结果表明:成熟孢子黄褐色,赤道面观为豆形,极面观椭圆形,单裂缝。孢子萌发类型为书带蕨型,原叶体发育为槲蕨型。成熟原叶体呈心脏形。毛状体在原叶体阶段出现。有性生殖周期长及配子体发育成幼孢子体的百分率低是扇蕨在配子体世代的主要濒危原因。此外,红壤固有的理化性质导致扇蕨配子体发育极其缓慢、精子器和颈卵器发生的时间间隔过长使其不能受精产生孢子体。原生植被遭受破坏引起的林下腐殖质土消失、红壤裸露,加剧了扇蕨的濒危。
The spores of Neocheiropteris palmatopedate were cultured in improved Knop＇s medium, in-situ humus soil and red soil respectively. Spore germination and gametophyte development were observed under optical microscope and dissecting microscope, and the impact of four culture methods on the gametophyte development and sexual reproduction was compared. On these experiments, its cause of endangerment was analyzed. The results showed that the mature spores are yellow-brown, monolete, and bean-shaped in equatorial view and elliptical in polar view. The pattern of spore germination is of the Vittaria-type and the gametophyte development of the Drynaria-type. The adult prothalli are cordate. Trichomes occurred in prothallus stage. The long period of sexual reproduction and the low rate at which gametophytes develop into sporophytes are the main reason for the endangerment of Neocheiropteris palmatopedata in sporophyte generation. Moreover, the extremely slow development of gametophyte and time interval between the appearance of antheridia and archegonia resuiting from the inherent physiochemical property of red soil make it impossible to fertilize and generate sporophyte. Therefore, the disappearance of humus soil under woods and the appearance of red soil caused by primary vegetation destruction aggravate the endangerment situation of Neocheiropteris palrnatopedata.
出处
《云南植物研究》
CSCD
北大核心
2009年第2期138-144,共7页
Acta Botanica Yunnanica
关键词
扇蕨
配子体发育
濒危机制
Neocheiropteris palmatopedata
Gametophyte development
Endangerment mechanism
