云南野生莲瓣兰形态分异与海拔的关系

Relationship between morphology and elevation in native Cymbidium tortisepalum in Yunnan Province,China

莲瓣兰是中国西南地区特有的兰科濒危物种。2013年和2014年8月至10月,在云南省西北地区选取了28个野生莲瓣兰居群进行野外调查。结果表明:野生莲瓣兰在滇西北海拔为1380—2557 m的区域均有分布;莲瓣兰叶片数、花葶长、花瓣长、花瓣宽、萼片长均与海拔呈显著负相关(P<0.01)。与年平均气温呈正相关的形态指标有:叶长(P<0.05),株高(P<0.05),花葶长(P<0.01)。与空气湿度呈显著正相关的形态指标有:叶宽(P<0.05),株高(P<0.05),花葶长(P<0.05),叶长(P<0.01)。随着野生莲瓣兰分布地海拔的升高,株型矮化,形态变小;年均温越高、空气湿度越大的分布地,莲瓣兰叶片越长、越宽,植株越高,花葶越长;分布地辐射强度越大,莲瓣兰叶片越短,植株越矮,根系越发达。野生莲瓣兰居群间的叶长、叶宽、株高、根长及花葶长度的变化较大,变异系数超过了15%,表明其存在着较大的形态变异,生态适应幅度变宽,且植株矮化严重,需加强就地和迁地保护。研究结果阐明了滇西北海拔、温度等生态因子对野生莲瓣兰形态特征的影响,为进一步保护野生莲瓣兰资源提供了理论依据。

Cymbidium tortisepalum is an endemic and endangered orchid species in southwestern China. Twenty-eight native populations of Cymbidium tortisepalum in northwest Yunnan Province were studied from August to October in 2013 and 2014. Native Cymbidium tortisepalum were distributed in elevations 1380-2557 m; The number of leaves, scape length, petal length, petal width, and sepal length were all negatively correlated with altitude （P〈0.01）; leaf length （P〈0.05）, height （P〈0.05）, and scape length （P〈0.01） were all positively correlated with the average annual temperature. Leaf width （P〈0.05）, height （P〈0.05）, scape length （P〈0.05）, and leaf length （P〈0.01） were all positively correlated with air humidity. Moreover, it was observed that the higher the altitude, the smaller the plant; the higher the average temperature or air humidity, the longer and wider the leaf blade; the taller the plant, the longer the scape; the stronger the radiation intensity, the shorter the blade; and the more dwarfed the plant, the more developed the root. The great changes among populations in wild Cymbidium leaf length, leaf width, plant height, root length and scape length. The coefficient of variation was greater than 15%, which indicates that there is a wide range of ecological adaptability, a large variation in morphology and the plant dwarfing serious, it is urgent to strengthen in situ and ex situ conservation. The effects of ecological factors, including altitude and temperature, on the characteristics of wild Cymbidium tortisepalum provide a theoretical basis for the further protection of wild Cymbidium tortisepalum.