忍冬科的系统发育核糖体DNA ITS区序列证据

以败酱草科Valerianaceae的Centranthu rubber为外类群,使用Phylip 3.65软件对忍冬科Caprifoliaceae 12个属12个代表种的ITS区序列进行了系统发育分析.采用最大简约法分析获得了5个最简约树,步长为580,一致性指数(CI)和维持性指数(RI)值分别为0.783 2和0.741 5.利用5个最简约树获取严格一致树.结果表明:①荚蒾属Viburnum与接骨木属Sambucus是姐妹群,自展支持率100%;并与忍冬科内七子花属Heptacodium、锦带花属Weigela构成姐妹群,虽然自展支持率为60%,从遗传距离上可看出荚蒾属与忍冬科内其他属之间仍有较近的亲缘关系,所以支持荚蒾属和接骨木属置于忍冬科内.②忍冬属Lonicera与鬼吹萧属Leycesteria聚成一小支,并构成姐妹群,自展支持率为100%;并与毛核木属Symphoricarpos、莛子镳属Triosteum构成姐妹群,自展支持率为100%,故不支持将毛核木属置于北极花族内Linnaceae;北极花属Linnaea、六道木属Abelia、猬实属Kolkwitzia、双盾木属Dipelta聚成姐妹群,自展支持率为100%,说明四者亲缘关系较近,仍置于北极花族内.

Phylogeny of Caprifoliaceae Inferred from the Sequence Analysis of the nrDNA ITS Region

In this study,the sequences of nrDNA ITS region of 12 species representing 12 sections of Caprifoliaceae and one outgroup,Centranthu ruber,are used to reconstruct the phylogeny of the family using Phylip3.65.Five most parsimonious trees(Length=580,CI=0.783 2 and RI=0.7415) are derived from the analysis with Centranthu rubber as the outgroup.The results are as follows:(1) Viburnum and Sambucus are in a sister group to form a subclade with a bootstrap value of 100%,and the two genera and Heptacodium and Weigela form a sister group with a bootstrap value of 60%.Viburnum and other genera in Caprifoliaceae have a close affinity gaining from the genetic distances,so it is revealed that Viburnum and Sambucus are included in Caprifoliaceae;(2) Lonicera and Levesteria are in a sister group to form a subclade with a bootstrap value of 100% and together with Symphoricarpos and Triosteum to form a sister group with a bootstrap value of 100%,thereby it is suggested that Symphoricarpos should be out of Linnaceae.Linnaea,Abelia,Kolkwitzia and Dipelta assemble a sister group with a bootstrap value of 100%,these reveal that they are close affinity and should be plisted in Linnaceae.