基于叶绿体DNA atpB-rbcL区序列探讨石蒜属种间系统发育关系

摘要：为了探讨石蒜属（Lycoris Herb.）的种间系统发育关系，对石蒜属95个材料包括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，结果表明：在系统发育树上亲缘关系近的材料聚在一起，其中矮小石蒜（L. radiata var. pumila）和换锦花（L. sprengeri）与2个人工杂交种（Hybrid 1、Hybrid 2）、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。

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

Abstract: The atpB-rbcL spacer region of chloroplast DNA (cpDNA) was sequenced from selected taxa for a better understanding of the phylogenetic relationships in the genus Lycoris. The taxa based on atpB-rbcL sequences were clearly classified into two main clades. As a result, the closely related species grouped together in the branches showing more precise and resolved relationships among studied taxa, and a well resolved and highly supported atpB-rbcL tree of Lycoris was obtained. L. radiata var. pumila, L. sprengeri, show compacted relationship with L. caldwellii, L. albiflora, L. straminea and L. houdyshelii, The result of atpB-rbcL sequences analyses is concordant with morphological and karyotype classification in certain respects and discordant in others. The concordancy shows all the subtelocentric chromosome species formed the clade I, and all the telocentric and metacentric chromosomes species formed the second clade II. The discordancy shows all with mixtures of subtelocentric, telocentric and metacentric chromosomes species dispersed in the two clades. The hypothesis of hybrid origin of these species is reinforced, comparing two artificial hybrids; atpB-rbcL sequence analysis also revealed that the subtelocentric chromosomes of L. albiflora and L. caldwellii derived from L. sprengeri, while L. houdyshelii and L. straminea was from L. radiata var. pumila.