Page 75 - 《广西植物》2023年第10期
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10 期 李文胜等: 横断山区六种八居群鼠尾草属植物的核型分析 1 8 2 9
Abstract: Salvia is the largest genus of the Lamiaceae. Several species of Salvia are used as traditional Chinese
medicineꎬ as well as ornamental species. To explore the evolution pattern of species in Hengduan Mountains at the
cytological level and to discuss the taxonomic relationship between morphological taxonomy and molecular systematicsꎬ
based on extensive collection of chromosome literatureꎬ the karyotypes of six species (eight populations) of Salvia
collected from Hengduan Mountains were analyzed by using conventional plant pressing methodꎬ and the chloroplast
phylogenetic trees of Salvia distributed in China were constructed. The statistical results were as follows: (1) About 23%
of the chromosome data of Salvia was reported all over the worldꎬ in which the chromosome reporting rate of Salvia in
China was 32.10%. The reporting rate of Salvia in Hengduan Mountains was 40.54%. (2) The chromosome basic number
of Salvia were mainly x= 8 and x= 11ꎬ and the chromosome cardinal numbers of Salvia plants distributed in China were
x = 8. The experimental results were as follows: (1) The karyotype data of S. wardii was reported for the first time. (2)
The diploid population of S. evansiana was found for the first time in Deqenꎬ Yunnan. The chromosome evolutionary
association analysis was carried out by combining cytological data with chloroplast evolution treeꎬ and it was
demonstrated that polyploidy might not be the main mechanism of Salvia adapting to high altitude environment. It showed
that polyploid was not the main evolutionary pathway of Salvia plants species formationꎬ but mainly at the level of
diploid. So we speculated that the doubling of genome might be one of the reasons for the inconsistency between species
morphology taxology and molecular phylogeny taxology. This study enriches the chromosome karyotype data of Salvia in
Hengduan Mountainsꎬ discusses the evolutionary relationship of chromosome characteristics combined with regional
molecular phylogenetic treeꎬ has made exploration for further study of the karyotype evolution of Salvia species in the
futureꎬ and complements the basic data for the deduction and analysis of the chromosome cardinal number of ancestral
species.
Key words: Hengduan Mountainsꎬ Salviaꎬ karyotype analysisꎬ chromosome evolutionꎬ phylogeny
横断山区位于“ 世界屋脊” 青藏高原东南部ꎬ 该属物种在生长形态、花形态等方面表现出显著
包括云南西北部、四川西部、西藏东部、青海南部 的多样性ꎮ 吴征镒和李锡文(1982) 认为鼠尾草属
以及甘肃西南部地区ꎬ面积约 36.4 万平方千米(李 的唇形花冠更适应昆虫传粉ꎬ因此是更进化和特
炳元ꎬ 1987)ꎮ 横断山区因南北走向的山脉ꎬ海拔 化的类群ꎬ并且认为横断山地区是该属形成和多
落差大ꎬ以及受印度洋暖湿气流的影响ꎬ形成了显 样化的中心之一ꎮ 尽管部分研究人员对产于西喜
著的沿海拔梯度变化的多种气候类型的生态环 马拉雅地区的鼠尾草进行了细胞学研究ꎬ但是对
境ꎬ包括低海拔的干热河谷地区ꎬ中海拔的暖温带 横断山区鼠尾草属植物的细胞学资料仍研究较少
地区及高海拔的高山冰缘带地区ꎬ形成了横断山 (Gillꎬ 1970ꎻ Bhattacharyaꎬ 1978ꎻ Haqueꎬ 1980)ꎮ
区丰富的物种多样性ꎮ 正因如此ꎬ横断山区成为 细胞学核型分析是研究植物进化地位及种群
全球重要的生物多样性研究中心之一ꎬ也因物种 间亲缘关系常用的方法之一ꎬ通过对中期细胞染
多样性丰富而成为研究物种起源演化的天然实验 色体组的数目、倍性、形态、大小、着丝粒位置、随
基地( 杨勤业等ꎬ 1988ꎻ曾广权等ꎬ 2000ꎻ 姚永慧 体有无等特征分析ꎬ再通过计算臂比、染色体长度
等ꎬ 2010)ꎮ 比、着丝粒指数、染色体长度变异系数以及着丝粒
唇形科( Lamiaceae) 鼠尾草属( Salvia) 是世界 指数变异系数等一系列核型参数计算ꎬ来对物种
性广布的大属ꎬ广泛分布于中美洲、南美洲、西亚 进行分类学研究ꎬ分析其亲缘关系和进化地位ꎮ
和东亚地区(Walker & Sytsmaꎬ 2007)ꎬ全世界范围 研究资料表明鼠尾草属的染色体数目具有多样
共计约 980 种( Hu et al.ꎬ 2018)ꎮ 西亚和地中海 化ꎮ Stewart(1939)对美国加利福尼亚地区 5 个亚
地区被认为是鼠尾草的原始分布中心( Masoud et 属 18 种鼠尾草属植物的染色体数目进行研究ꎬ发
al.ꎬ 2010)ꎮ 原产中国的鼠尾草种类有 81 种 24 变 现染色体基数为 x = 8、12、16ꎮ Fujita(1970) 根据
种ꎬ横断山区有 37 种 13 变种( 中国科学院青藏高 其染色体基数为 x = 11ꎬ认为鼠尾草属是唇形科中
原综合科学 考 察 队ꎬ 1993ꎻ Li & Hedgeꎬ 1994)ꎮ 最原始的属ꎬ并且是唇形科中染色体基数最高的