杜鹃属轮叶组类群的导管穿孔板多样性与系统发育的联系

认识穿孔板多样性与系统发育的联系,对了解植物导管解剖结构与系统发育的相互关系具有重要意义,可为植物系统分类提供有效的信息.通过对应分析杜鹃属轮叶组类群导管穿孔板多样性与ITS序列,得到如下结论:(1)应用分子标记与穿孔板多样性结合起来分析可以使穿孔板多样性变化与系统发育的联系更加明晰,分析表明穿孔板的多样性与系统发育有明显的联系.(2)穿孔板多样性与系统发育的联系主要表现为3个途径:即典型梯形穿孔板与系统发育有明显的联系;网状-梯形混合穿孔板对种以下等级的系统发育有明显的联系;穿孔板的面积.变化与系统发育有明显的联系.(3)导管穿孔板多样性与分子标记的对应分析结果可为系统分类提供明晰、可信的证据,本文通过对应分析认为,戴云山杜鹃可能是一个种下级分类单位.(4)穿孔板多样性变化与ITS序列的对应分析使穿孔板的演化方向更加明确:即穿孔板的演化与系统发育方向一致.

A Study on the Connection of D iversity with Phylogeny of Vessel Perfora tionPla tes of Taxon of Rhododendron Sect. B rachyca lyx Sweet ( Er icaceae)

The diversity of vessel perforation p lates of p lants is important to understand how the connection ofdiversity of vessel perforation p lates with phylogeny occurs. This information will help us to understand therelationship between diversity of perforation p lates and phylogeny. For this reason , taxon of Sect. B rachycalyx ofRhododendron in the mainland of China were selected as samp les to make a study on the connection. The results ofthe study are as follows : (1) The connection of diversity of vessel perforation p lateswith phylogeny of this taxon ismore p ronounced based on the corresponding analysis of both diversity of vessel perforation p lates and phylogeny.(2) The connection of diversity of perforation p lateswith phylogeny of this taxon is revealed in three ways as follows:the first, typ ical scalariform perforation p late (A1) responds to phylogeny more clearly ; the second, reticulatescalariform perforation p late (B ) responds to phylogeny of infra rank of species ; the third, changes in area ofperforation p lates respond to phylogeny . (3) The method of corresponding analysis by combination of diversity ofperforation p lates with molecular marker sequences will enable a study to offer clear and faithful information forsystemic classification , for examp le , the results of the study suggest that species Rhododend ron daiyuenshanicum Tam should be treated as an infra rank of species. (4) The method of corresponding analysiswith molecularmarkersequences is the best way to get definite direction of evolution of perforation p lates of p lants and it suggests thatevolution of perforation p lates of Rhododendron Sect. B rachycalyx is responding to phylogeny of this taxon.