植物分类学报
植物分類學報
식물분류학보
ACTA PHYTOTAXONOMICA SINICA
2008年
2期
142-154
,共13页
王奇志%何兴金%周颂东%吴耘珂%余岩%逄云莉
王奇誌%何興金%週頌東%吳耘珂%餘巖%逄雲莉
왕기지%하흥금%주송동%오운가%여암%방운리
柴胡属%染色体%横断山区%ITS序列%系统发育%分类
柴鬍屬%染色體%橫斷山區%ITS序列%繫統髮育%分類
시호속%염색체%횡단산구%ITS서렬%계통발육%분류
Bupleurum%chromosome%Hengduan Mountains%ITS%phylogeny%taxonomy
横断山区是中国柴胡属Bupleurum植物的分布中心.本文对横断山区6个种2变种进行了染色体记数报道,其中4个种2变种是首次报道.对横断山区的10个种4个变种、中国北方(河北和黑龙江)的3个种的nrDNA ITS进行测序,同时从GenBank里面下载同属的来自非洲和地中海西部的16个nrDNA ITS序列数据,结合染色体数目变化结果.初步探讨了横断山区柴胡属植物的系统发育.结果表明横断山区可能是现代胡属植物的频度中心和多样分布中心之一.它们的祖先种可能是非洲北部的木本柴胡属植物B.fruacosum,或者是地中海西部的柴胡属植物,推测是通过中东和高加索扩散而形成的,其中与非洲南部特有种B.mundtii的亲缘关系也较近;染色体基数演化趋势是:8是较原始基数,6和7是次生基数,其染色体异基数变异和多倍化可能是物种形成、进化以及向外扩散的主要方式;在ITS系统发育树中,中国柴胡属植染色体基数为8的种类聚为一支.染色体基数为6和7的种类聚为了一支,不支持舒璞等(1998)关于中国柴胡属的属下分类系统.结合已有的形态学、细胞学、孢粉学证据和ITS系统发育树,建议窄竹叶柴胡B.marginatum var.stenophyllum独立成种.
橫斷山區是中國柴鬍屬Bupleurum植物的分佈中心.本文對橫斷山區6箇種2變種進行瞭染色體記數報道,其中4箇種2變種是首次報道.對橫斷山區的10箇種4箇變種、中國北方(河北和黑龍江)的3箇種的nrDNA ITS進行測序,同時從GenBank裏麵下載同屬的來自非洲和地中海西部的16箇nrDNA ITS序列數據,結閤染色體數目變化結果.初步探討瞭橫斷山區柴鬍屬植物的繫統髮育.結果錶明橫斷山區可能是現代鬍屬植物的頻度中心和多樣分佈中心之一.它們的祖先種可能是非洲北部的木本柴鬍屬植物B.fruacosum,或者是地中海西部的柴鬍屬植物,推測是通過中東和高加索擴散而形成的,其中與非洲南部特有種B.mundtii的親緣關繫也較近;染色體基數縯化趨勢是:8是較原始基數,6和7是次生基數,其染色體異基數變異和多倍化可能是物種形成、進化以及嚮外擴散的主要方式;在ITS繫統髮育樹中,中國柴鬍屬植染色體基數為8的種類聚為一支.染色體基數為6和7的種類聚為瞭一支,不支持舒璞等(1998)關于中國柴鬍屬的屬下分類繫統.結閤已有的形態學、細胞學、孢粉學證據和ITS繫統髮育樹,建議窄竹葉柴鬍B.marginatum var.stenophyllum獨立成種.
횡단산구시중국시호속Bupleurum식물적분포중심.본문대횡단산구6개충2변충진행료염색체기수보도,기중4개충2변충시수차보도.대횡단산구적10개충4개변충、중국북방(하북화흑룡강)적3개충적nrDNA ITS진행측서,동시종GenBank리면하재동속적래자비주화지중해서부적16개nrDNA ITS서렬수거,결합염색체수목변화결과.초보탐토료횡단산구시호속식물적계통발육.결과표명횡단산구가능시현대호속식물적빈도중심화다양분포중심지일.타문적조선충가능시비주북부적목본시호속식물B.fruacosum,혹자시지중해서부적시호속식물,추측시통과중동화고가색확산이형성적,기중여비주남부특유충B.mundtii적친연관계야교근;염색체기수연화추세시:8시교원시기수,6화7시차생기수,기염색체이기수변이화다배화가능시물충형성、진화이급향외확산적주요방식;재ITS계통발육수중,중국시호속식염색체기수위8적충류취위일지.염색체기수위6화7적충류취위료일지,불지지서박등(1998)관우중국시호속적속하분류계통.결합이유적형태학、세포학、포분학증거화ITS계통발육수,건의착죽협시호B.marginatum var.stenophyllum독립성충.
Hengduan Mountains are the diversity center for the genus Bupleurum of Apiaceae in China.This Paper reports chromosome numbers of six species and two varieties of Bupleurum,and for four species and two varieties their chromosome numbers are reported for the first time.The phylogeny of Bupleurum was investigated based on the ITS region of the nuclear ribosomal DNA(nrDNA)of 14 taxa from the Hengduan Mountains,3 taxa from the North China(Hebei and Heilongjiang),and 16 taxa from Africa and the Mediterranean region.Variations in chromosome numbers and the ITS sequences were used to infer Phylogenetic relationships between Bupleurum species in Hengduan Mountains.The results showed that the Hengduan Mountains might represent one of the frequency and diversity centers for Bupleurum.The ancestors of Bupleurum species in the Hengduan Mountains may be related to the woody B.fruticosum in North Africa,or the species in the western Mediterranean region.It is postulated that the ancestral population migrated into Hengduan Mountains through the Middle East and the Caucasus.Furthermore,the neo-endemic B.mundtii in South Africa appeared to be a close relative of the species in the Hengduan Mountains.In the trend of basic chromosome number evolution,x=8 should be regarded as the ancestral basic number,while x=6.7 as the derived ones.The Bupleurum species in the Hengduan Mountains have been undergoing changes in the basic chromosome numbers or the ploidy level.The ITS phylogenetic tree showed that the Chinese species were divided into two clades:one with the basic chromosome number x=8,and the other with x=6,7.The results rejected the previous infrageneric classification of Bupleurum in China.We further suggested to raise B.marginatum Var.stenophyllum to species rank based on the combined evidence from morphology,karyology,pollen morphology,and the ITS phylogenetic tree.