基于3种基因序列对百合属Leucolirion组的系统发育与种间关系研究

中国拥有丰富的野生百合种质资源,但有关百合属的系统发育与进化关系研究相对较少。该研究基于ITS、cpDNA(trnV-ndhC、petL-psbE)及单拷贝核基因AKT等3个基因片段,选取特有分布于西南地区的百合属6个近缘类群共48份样本及GenBank获得的数据,对百合属Leucolirion组进行了系统发育与种间关系研究。结果表明:(1)ITS结果支持前人的处理,即将Leucolirion组细分为2个亚组,subsect.Leucolirion6a和subsect.Leucolirion6b。建议将湖北百合(L.henryi)和南川百合(L.rosthornii)归入到subsect.Leucolirion 6a,与泸定百合(L.sargentiae)、淡黄花百合(L.sulphureum)、宜昌百合(L.leucanthum)和岷江百合(L.regale)等4个种一起组成Leucolirion组;原本属于Archelirion组的野百合(L.brownii)与subsect.Leucolirion6b聚为一支,故将它与台湾百合(L.longiflorm)、麝香百合(L.formosanum)等组成一个新组,命名为百合组(sect.Lilium)。(2)组间关系上,Leucolirion组与百合组的系统发育关系较远,前者与分布于日本的Archelirion组形成姐妹类群,而后者与Sinomartagon组的亲缘关系更近。(3)基于叶绿体联合基因和单拷贝核基因AKT的6个近缘种的遗传距离显示,湖北百合与南川百合明显区别于Leucolirion组内拥有白色管状花的4个类群。叶绿体联合基因树和单拷贝核基因树结果表明,泸定百合、淡黄花百合、岷江百合和宜昌百合在遗传水平上表现出了极高的相似性,遗传关系十分相近,这可能与百合属植物特殊的繁育系统有关,影响了物种间遗传变异与分化。

Phylogeny and Interspecific Relationship of Lilium Section Leucoliron Based on Three Gene Sequences

Despite abundant germplasm resources of wild lilies in China, the study of phylogenetic and interspecific relationship in Lilium was scarce. In this study, phylogeny of the section Leucolirion Comber which includes GenBank data and 48 specimens covering 6 closed related lilies endemic to Southwest China was explored based on ITS, cpDNA and a single copy nuclear gene, AKT. The results showed that: (1) in accordance with previous studies that the section Leucolirion Comber should be divided into two subsection, subsect. Leucolirion 6a and subsect. Leucolirion 6b, and L. henryi and L. rosthornii should be classified into subsect. Leucolirion 6a. We revise section Leucolirion including L. sargentiae, L. sulphureum, L. leucanthum, L. regale, L. henryi and L. rosthornii. L. bownii, which originally belonged to section Archelirion was placed into subsect. Leucolirion 6b, along with L. formosanum and L. longiflorum, we establish a new group, named section Lilium. (2)As for infrageneric relationships, section Archelirion which mainly distributes in Japan showed a sister relationship with section Leucolirion. However, section Lilium and Sinomartagon showed a close relationship. (3) The genetic distances among all taxa of chloroplast combination and AKT showed that L. henryi and L. rosthornii distinctly differ from other members of section Leucolirion. Phylogenetic tree based on chloroplast combination data, AKT fragment indicated that L. sargentiae, L. sulphureum, L. regale and L. leucanthum have a very close relationship. High genetic similarity between these species may be attributed to the particular mating system of Lilium, leading to limited genetic variation and differentiation among species.