基于ITS、rpl16和trnS-trnR DNA序列讨论锥形果属的系统位置

基于核基因ITS和叶绿体基因rpll6、trnS-trnR的DNA序列讨论了锥形果属的系统位置,3个基因片段独立以及联合的分析为锥形果属Gomphogyne的系统进化研究提供了足够的信息.结果表明:(1)锥形果属是一个自然属;(2)雪胆属Hemsleya的短柄雪胆H. delavayi和圆锥果雪胆H. macrocarpa曾经被作为锥形果属的种,分子证据表明它们确实隶属于雪胆属;(3)锥形果属单独构成雪胆属的姊妹群,而并非是与绞股蓝属Gynostemma共同构成.

Systematic position of Gomphogvne (Cucurbitaceae) inferred from ITS, rpl16 and trnS-trnR DNA seq uences

This paper assessed the systematic position of the genus Gomphogyne.The nuclear ITS,the chloro-plast rpll6,and trnS-trnR sequences were used to reconstruct the phylogeny of Gomphogyne and its related gen-era.Analyses of three separate and combined datasets provided a good amount of informative characters and re-solved the systematical relationships of Gomphogyne well.The maximum parsimony analyses revealed that:(1) Gomphogyne was a natural genus and was different from the genera Hemsleya and Gynostemma;(2)Hemsleya delavayi and H. macrocarpa did not belong to the genus Gomphogyne,but to the genus Hemsleya;and(3) Gomphogyne was sister to Hemsleya.It was assured that Gomphogyne was a monotypic genus.These results were largely in agreement with the systems of classification of the Cucurbitaceae of Jeffrey in 1990 and in 2005 and with that of Li for Hemsleya in 1993,but were different from the previous studies in which Gomphogyne and Gy-nostemma together were suggested to be sister to Hemsleya.