Abstract:

Pinus squamata X. W. Li, a recently-described species of the Pinaceae, is an extremely endangered pine with only 32 individuals in the wild. This species was thought to be intermediate between P. bungeana Zucc. ex Endl. of subgen. Strobus and P. yunnanensis Franch. of subgen. Pinus by the original author. We made an effort to address the question of the phylogenetic relationship of this peculiar and important species in the context of the major groups of the genus Pinus by using sequences of the rbc L, mat K genes, rpl20-rps18 spacer, trn V intron of the chloroplast genome and the nuclear ribosomal ITS region. The results of the separated analysis and the combined analysis of the four cpDNA sequences and ITS sequence indicated that P. squamata was a stable member of subsect. Gerardianae and P. gerardiana Wall. was the closest species of P. squamata phylogenetically. As a result, the causes of the distribution pattern of subsect. Gerardianae were also discussed.

由5个DAN 片段推断极度濒危植物五针白皮松的系统位置
张志勇 杨俊波  李德铢

（1. 中国科学院昆明植物研究所生物多样性与生物地理开放实验室，昆明650204；
2. 江西农业大学农学院，南昌330045）

摘要： 五针白皮松 (Pinussquamata X .W .Li)是上世纪 90年代描述的一种中国特有松树 ,目前野外只有立木 32株 ,处于极度濒危状态。前人认为这个种可能是白松亚属 (subgen .Strobus)的白皮松 (P .bungeana Zucc .exEndl.)与松亚属 (subgen .Pinus)的云南松 (P .yunnanensis Franch .)的过渡类型 ,并将其归入白皮松组狐尾松亚组 (subsect. Balfourianae)。本文试图在前人分子系统学工作的基础上 ,检测五针白皮松 5个DNA片段 ,叶绿体基因rbcL、matK、rpl2 0-rps18间隔区和trnV内含子以及核糖体ITS ,将五针白皮松放在整个松属中探讨其系统位置。 4个叶绿体基因单独分析结果和它们的联合数据分析结果以及根据ITS得到的系统树均表明 ,五针白皮松是白皮松亚组 (subsect.Gerardianae)的一个稳定成员 ,其可能的姐妹群是西藏白皮松 (P .gerardiana Wall.)。对白皮松亚组的地理分布作了初步探讨。

关键词： 五针白皮松；系统学关系rbc L; mat K; rpl20-rps 18 间隔区；trnVE 内含子；ITS

通讯作者。E-mail:dezhli @ hotmail.com。