樟科黄肉楠属是一个复系类群——基于nrDNA ITS和ETS序列分析(英文)

Polyphyly of the genus Actinodaphne (Lauraceae) inferred from the analyses of nrDNA ITS and ETS sequences

应用nrDNAITS和ETS序列探讨了樟科Lauraceae黄肉楠属Actinodaphne的系统演化关系。对得到的3个序列矩阵(ITS、ETS和ITS/ETS),采用MP(maximumparsimony),ML(maximumlikelihood)和Bayesian3种分析方法进行了系统发育分析。结果显示,本文选的黄肉楠属Actinodaphne物种与所选的月桂族中的外类群靠近并混和在一起,进一步证实了本属为一个复系类群。结合对传统的形态学性状的重新认识,认为花序类型特征可能是重新界定黄肉楠属的最重要的性状,具有相同花序类型的物种可能具有相同的起源。然而,由于取样数量相对较少以及对矩阵的单独分析存在一定的差异,还需更详细的研究来验证本文对黄肉楠属系统演化关系的假设,并进一步更精确地重建本属的系统发育关系。

A phylogenetie analysis of the genus Actinodaphne （Lauraceae） was conducted using sequences from the nrDNA （nuclear ribosomal DNA） internal transcribed spacer （ITS） and external transcribed spacer （ETS） regions. Maximum parsimony （MP）, maximum likelihood （ML） and Bayesian phylogenetie analysis methods were employed to analyse the data sets （ITS, ETS and ITS/ETS）. All analyses suggested that the sampled Actinodaphne species were not monophyletie, clustering instead as several elades amongst other genera in the tribe Laureae. This result indicates that the generic delimitations between Actinodaphne and related genera need to be reevaluated, and that inflorescence features, which are mostly consistent with the current molecular inferences, might be the both important and reliable characters for their redefinition. However, because of the relatively small number of taxa sampled, and conflicts between the separate analyses, more detailed studies are required to clarify the relationships which emerged in our study and to allow for more precise generic delimitation and hypotheses about phylogeny in Actinodaphne.