云南迪庆州野生莲瓣兰形态分异与海拔的关系

Relationship between Morphological Differentiation and Elevation of Wild Cymbidium tortisepalum in Diqing of Yunnan Province

迪庆州位于云南省西北部滇、藏、川三省区交界处,具有丰富的地质地貌多样性、生物多样性和自然景观多样性。境内的维西傈僳族自治县至德钦县的一段区域是野生莲瓣兰的重要分布区之一,本研究于2013年8月1—25日在该区域进行实地调查,采集野生莲瓣兰资源,共发现14个野生莲瓣兰居群,并测定株高、叶长和叶宽等形态特征。结果表明:野生莲瓣兰的株高、叶长、叶宽与分布地海拔高度呈显著的负相关关系(P<0.05),表现为海拔越高,其叶片越窄(R2=0.724 8),植株越矮(R2=0.581 2),叶片越短(R2=0.463 4);但海拔高度对莲瓣兰的叶片数量影响较小;明确提出维西傈僳族自治县的西北坡向、西坡向和北部坡向是野生莲瓣兰的主要分布区。研究结果阐明了该区域海拔等生境因子对野生莲瓣兰形态特征的影响,为进一步深入研究和保护野生莲瓣兰资源奠定了基础。

Diqing, a region rich in geological landforms, biological and landscape diversity located in the junction of three province namely Yunnan province, Tibet and Sichuan province, is one of the most important distribution areas of wild Cymbidium tortisepalum. In this study, 14 wild C. tortisepalum populations were collected in the area including Weiden Township of Weixi County and Yanmen Township of Diqing during the field investigation, and the morphological characteristics of plant height, length and width of leaf, etc. were measured from August 1^st to 25^th in 2013. The results showed that there was a significant negative correlation relationship betweent he morphological characteristics of plant height, leaf length and leaf width and altitude of distribution of C. tortisepalum （ P 〈0. 05 ）. It is found that the higher the altitude is, the narrower leaves become （ R^2 = 0. 724 8 ）, the shorter the plants （R^2 =0. 581 2） and leaves become （R^2 =0. 463 4）, however, leaf number of C. tortisepalum was affected less by altitude. The study presented explicitly that northwestern, western and northern slope are the main distribution area of C. tortisepalum. These results illustrated that the morphological characteristics of C. tortisepalum were affected by the habitat factors such as elevation, gradient and slope direction of population distribution site. The results can provide a foundation for further study and protect the rare orchid.