菝葜属圆锥菝葜组的RAPD分析及系统发育研究初报

A preliminary phylogeny study and RAPD analysis of Sect. Macranthae Kunth. in Smilax L

利用随机扩增多态 DNA(RAPD)分析技术 ,选取 13个 10 bp长度的随机引物 ,对菝葜属圆锥菝葜组的 6种菝葜及其近缘种进行了 DNA多态性研究 ,对扩增产物用 DPS2 0 0 0可变类平均法进行聚类分析 .结果表明 :1该组植物 DNA的随机引物扩增多态性较丰富 ,13个引物共得到 2 73个条带 ,组内种间表现出较近的遗传距离 ,体现出具有共同祖先的特征 ;2同种不同个体具有相对一致的条带 ,也最早聚合 ,表明 RAPD在种内是相对稳定的 ,具有一定的系统学意义 ;3海南岛产的材料具有一定的独特性 ,值得进一步研究 ;4马达加斯加的菝葜 (Smilax anceps)和外类群薯蓣科的薯蓣、百合科的油点草总是首先聚合在一起 ,表明了马达加斯加菝葜的独特性 ,以及在分子水平体现的共同祖征 .也说明菝葜的起源可以追溯到地球板块分离以前 .在板块分离后 ,该种菝葜在马达加斯加独立生长 ,保留了更多与其他近缘单子叶植物的祖先性状 ,而保留在亚洲大陆的其它菝葜种则不断演化 ,出现了 DNA结构上的分化 ,表现出与薯蓣、油点草较低的同源率 ;5

Six species of Sect. Macranthae Kunth in Smilax L. and five affinitive species from Smilax, Dioscoreaceae and Liliaceae were analyzed by RAPD . Cluster analysis of the amplified data was conducted by using a variable average method in the program DPS2000. Result was showed as follows: ①273 bands of 13 primers were acquired through RAPD, which had the abundant polymorphism in this section. These species were showed that they had very close genetic distance between species in the section, derived from the common ancestor. ②RAPD bands of different individuals within definite species were same correspondingly in the cluster tree, which showed that RAPD was of classification sense in Smilax in some content. ③The Hainan populations of some species had the speciality in RAPD and it was valuable to the further research. ④Smilax anceps from Madagascar showed more affinity with one species of Dioscoreaceae and one of Liliaceae than the ones of Smilax from other continent. From this, we may draw a conclusion that the species derived from the common ancestor of Liliales in the old continent. After the separation and moving of the old continent, the species of Madagascar keep a long stabilization in a unique environment, so that some primitive characters were kept down which was ancestor characters and can be found in some species of Dioscoreaceae and Liliaceae. But much differentiation in morphological and genetic, even the DNA characters appear in Smilax species of the other continents. ⑤RAPD is valuable and helpful in the systematic and evolutionary research of Smilax.