祁连山高寒草甸两型闭锁花植物块茎堇菜的繁殖分配  

Reproductive allocation of dimorphic cleistogamous Viola tuberifera in alpine meadow of Qilian Mountain

作　　者：郝楠[1] 苏雪[1] 吴琼[1] 常立博 张世虎[1] 孙坤[1] 

机构地区：[1]西北师范大学生命科学学院,甘肃兰州730070

出　　处：《草业科学》2015年第4期586-592,共7页Pratacultural Science

基　　金：国家自然科学基金项目(31260054)

摘　　要：青藏高原及其边缘地区特有的块茎堇菜(Viola tuberifera)是典型的两型闭锁花结实植物,通过开放花、地上、地下闭锁花进行有性繁殖。为探讨其如何通过繁殖资源权衡适应高海拔环境,选择祁连山高寒草甸3个海拔梯度下块茎堇菜为对象,研究了其闭锁花盛花期的繁殖分配特征。结果发现,1)块茎堇菜营养生长和繁殖间、地上和地下闭锁花有性繁殖分配间存在权衡关系,有性和无性繁殖间可能存在权衡;2)块茎堇菜的有性繁殖分配具个体大小依赖性,与个体大小呈负幂指数相关;3)随海拔升高,总生物量显著减小(P<0.05),总有性繁殖分配下降,其中地上闭锁花繁殖分配下降,但地下闭锁花繁殖分配略有上升。繁殖方式也随海拔发生变化,在低海拔(2 800 m)以地上闭锁花为主,高海拔(3 100 m)以地下闭锁花和鳞茎为主。研究结果表明,块茎堇菜可能通过权衡地上和地下闭锁花的资源分配来获得最大的繁殖成效,以适应高海拔环境变化,保障在高寒环境中的生存和繁衍。Viola tuberifera,which endemic to Qinghai-Tibetan Plateau and its neighbor region,is a typical dimorphic cleistogamous plant.V.tuberifera conducts sexual propagation via both open,chasmogamous(CH) flowers and closed,obligate self-pollinating aerial and subterranean cleistogamous(CL) flowers.In present research,V.tuberifera in alpine meadow of Qilian Mountain within different altitude gradients during cleistogamous full-blossom period was chosen to investigate characteristics of reproductive allocations for understanding behavior of balancing propagation resource to adapt alpine environment.The results showed that: 1) Trade-offs existed not only in vegetation and reproduction,but also in aerial and subterranean cleistogamous flowers sexual reproduction,and probably in sexual and asexual reproduction; 2) Sexual reproductive allocation was size-dependent,and it was negative power exponent correlation between size and sexual reproductive allocation; 3) With the increase of altitude,it was declined drastically that individual size,total sexual reproductive allocation,and also descend in reproductive allocation of aerial cleistogamous flowers,while had a slightly elevated tendency in reproductive allocation of subterranean cleistogamous flowers and bulbs.Furthermore,the reproductive strategies were also changed with altitudes.In the low altitude(2 800 m),plants chose aerial cleistogamous flowers as major strategy,by contrast,preferring to subterranean cleistogamous flowers and bulbs in the high altitude.In a conclusion,the V.tuberifera may regulate reproductive allocations of aerial and subterranean flowers to gain maximum propagation success,adapting changes in high elevation and cold environment,ensuring survival and thrive of species in the alpine meadow ecosystem.

关 键 词：块茎堇菜 繁殖分配 权衡 闭锁花 鳞茎 海拔 生物量 

分 类 号：Q945.5[生物学—植物学]