干旱半干旱地区蓼科4属植物的系统发育关系研究

Study on Phylogeny of Four Polygonaceae Genera from Arid and Semiarid Areas

提取蓼科木蓼属(Atraphaxis)、沙拐枣属(Calligonum)、翅果蓼属(Parapteropyrum)和双翅果蓼属(Pteropy-rum)蓼科4属植物的总DNA,通过聚合酶链式反应(PCR),扩增其叶绿体基因片段atpB-rbcL。atpB-rbcL基因间区长约900 bp,已被广泛应用于属间系统发育关系的研究。运用PAUP和Bayesian软件,通过最大简约法、最大似然法和贝叶斯分析,建立系统发育树结果显示:4属中沙拐枣属和双翅果蓼属存在最近亲缘关系;而特产于中国西藏的翅果蓼属和其他3属关系较远;另外,沙拐枣属下4个组中基翅组、刺果组和翅果组聚于一小进化枝下,与泡果组相区别。

Atraphaxis,Calligonum,Parapteropyrum and Pteropyrum are all the genera of Polygonaceae distributed in arid and semiarid areas.The four genera have many similar characters in morphology.In China,Atraphaxis and Calligonum are mainly distributed in Xinjiang,and Parapteropyrum is endemic in Tibet.The genus Pteropyrum including 3-5 species can be found in Southwest Asia and Middle East.Total genomic DNA of Atraphaxis,Calligonum,Parapteropyrum and Pteropyrum was extracted from the leaves dried with silica-gel or from herbaria,the polymerase chain reaction（PCR） was used to amplify the chloroplast DNA atpB-rbcL region.The atpB-rbcL,the intergenic spacer between atpB gene and rbcL gene,about 900 bp in length,is widely used for the phylogenetic analysis on generic level.The phylogenetic tree based on the atpB-rbcL sequences reveals that Calligonum shows closer relation to Pteropyrum,additionally,Parapteropyrum is out of the clade including Calligonum,Pteropyrum and Atraphaxis.Within Calligonum,Section Calligonum,Section Medusa and Section Pterococcus formed a small clade,which is distinct from Section Calliphysa.