基于叶绿体DNA atpB-rbcL区序列探讨石蒜属种间系统发育关系

Investigation on the Phylogenetic Relationships of Lycoris (Amaryllidaceae) Based on Chloroplast atpB-rbcL Sequences

摘要:

为了探讨石蒜属(Lycoris Herb.)植物的种间系统发育关系,对石蒜属植物95 份材料,包括15种4变种及2个人工杂种的叶绿体DNA atpB-rbcL间隔区进行了测序,结合花部形态和核型特征,探讨了石蒜属种间系统关系及其可能的杂交起源。系统发育树的分析结果表明,矮小石蒜(L. radiata var. pumila)和换锦花(L. sprengeri)与2个人工杂交种、麦秆石蒜(L. straminea)、江苏石蒜(L. houdyshelii)、短蕊石蒜(L. caldwellii)和乳白石蒜(L. albiflora)具有密切的亲缘关系。atpB-rbcL序列揭示的石蒜属种间关系与染色体核型的分类结果部分一致,主要表现在具有近端部着丝粒(A)染色体的种与具有中部(M)和端部(T)着丝粒染色体的种各成一支,与形态和染色体分类结果一致;不同之处在于具有中部、端部和近端部着丝粒染色体的种分散在两个主要分支内,进一步验证了具有中部、端部和近端部3 种着丝粒类型染色体组的石蒜,如麦秆石蒜、江苏石蒜、短蕊石蒜和乳白石蒜等,是杂交起源的假设,结合2 个人工杂交种分析,揭示了短蕊石蒜和乳白石蒜的近端部着丝粒染色体来源于换锦花;麦秆石蒜和江苏石蒜近端部着丝粒染色体来源于矮小石蒜。

Abstract:

In order to understand the phylogenetic relationships in genus Lycoris, the atpB-rbcL spacer regions of chloroplast DNA (cpDNA) were sequenced from selected 95 taxa, including 15 species, 4 varieties and 2 hybrids. The results showed that 95 taxa were clearly classified into two main clades from phylogenetic tree based on atpB-rbcL sequences. There were close relationship among L. radiata var. pumila, L. sprengeri, L. caldwellii, L. albiflora, L. straminea and L. houdyshelii. The interspecific relationship revealed by atpB-rbcL sequences is partially consistent with morphological and karyotype classification. The species with subtelocentric chromosome grouped Clade I, and the species with telocentric and metacentric chromosomes formed Clade II. The species with subtelocentric, telocentric and metacentric chromosomes dispersed in the two clades, it verified the hypothesis that Lycoris species with subtelocentric, telocentric and metacentric chromosomes were hybrid origin. Combining the data from two artificial hybrids, atpB-rbcL sequence analysis also revealed that subtelocentric chromosomes of L. albiflora and L. caldwellii derived from L. sprengeri, while those of L. houdyshelii and L. straminea from L. radiata var. pumila.