基于DNA非编码区序列探讨罗布麻的分类问题

摘要

通过测定中国产罗布红麻、大叶白麻和白麻的ITS、trnL内含子和trnL-F非编码区序列,并与其它相关植物的相应序列比较,探讨"罗布麻"的系统分类.结果显示:罗布红麻、大叶白麻和白麻3种植物的ITS序列完全一致,而与罗布麻属加拿大麻的ITS序列相差较大;在trnL内含子和trnL-F非编码区,大叶白麻和白麻的完全一致,与罗布红麻之间仅有3个位点的变异,而加拿大麻与美国茶叶花在这3个位点却和白麻属的完全一致等.以上结果显示在ITS、trnL内含子和trnL-F非编码区,白麻属和罗布麻属之间没有本质区别,罗布红麻与大叶白麻和白麻之间的亲缘关系可能较罗布红麻与罗布麻属内其它物种间的亲缘关系更近.遗传距离与系统树的分析结果进一步支持以上推论.建议撤销白麻属,将大叶白麻和白麻合并到罗布麻属.%To study the taxonomy of 'Luobuma' ,3 non-coding regions of DNA sequences (nuclear ribosomal ITS,chloroplast trnL intron, and trnL-F region) of Apocynum venetum, Poacynum pictum and P.hendersonii from China were sequenced and analyzed together with other related species from GenBank.ITS sequences from A. venetum, P. pictum and P. hendersonii were all the same and differed a lot from those of A. cannabinum. TrnL intron and trnL-F region sequences from P. pictum and P. hendersonii were the same;they differed from those of A. venetum at 3 sites,but were identical at these 3 sites to sequences from A. cannabinum and A. androsaemifolium. These results demonstrated that there is no intrinsic difference between Apocynum L. and Poacynum L. and the relationship between A. venetum and species from Poacynum L. is closer than that between A. venetum and other species from Apocynum L. Analyses of genetic distances and phylogenetic trees further confirmed this deduction. All of above supported the view that P. pictum and P. hendersonii should be incorporated into the genus Apocynum L. and the genus Poacynum L. should be repealed.