三种蒲公英属植物DNA条形码序列的初步筛选  

Preliminary Screening of DNA Barcodes in Three Taraxacum Species

作　　者：李杨美汇 张义[1] 黄俊 杨雪 杨柯 戚继艳[1] 闫洁[2] 唐朝荣 Li Yangmeihui;Zhang Yi;Huang Jun;Yang Xue;Yang Ke;Qi Jiyan;Yan Jie;Tang Chaorong(College of Tropical Crops,Hainan University,Haikou,570228;College of Life Sciences,Shihezi University,Shihezi,832003)

机构地区：[1]海南大学热带作物学院,海口570228 [2]石河子大学生命科学学院,石河子832003

出　　处：《分子植物育种》2021年第15期5054-5061,共8页Molecular Plant Breeding

基　　金：国家杰出青年科学基金项目(31825007)资助。

摘　　要：橡胶草(Taraxacum kok-saghyz,TKS)作为天然橡胶替代资源,具有重要应用前景,但由于两种生活力更强的近缘种短角蒲公英(T.brevicorniculatum,TB)和普通蒲公英(T.officinale,TO)的广泛共域存在,TKS种质资源的收集和未来商业种植受到严重影响。为了在分子水平上鉴定这些蒲公英物种,并研究TKS及其近缘种之间的种群分化和进化关系,本研究以10株TKS、2株TB和2株TO野生资源为材料,对3种叶绿体DNA(trnH-psbA,petL,ycf1)和1种核DNA(ITS2)序列进行初步筛选。结果显示,ITS2和trnH-psbA存在较大的种间变异,可较好的区分这3种蒲公英植物,但二者的种内变异均极小,无法用于种内种群结构研究;petL和ycf1的种间和种内遗传距离均为0或接近0,在蒲公英植物上无应用价值。此外,基于ITS2和trnH-psbA序列的系统进化树分析表明,TB可能是由TKS(母本)和TO(父本)杂交后代进化而来的。本研究为下一步橡胶草种质资源研究提供了参考依据。Taraxacum kok-saghyz(TKS)has great potential as an alternative source of natural rubber.Two dandelion relatives of TKS.T.brevicorniculatum(TB)and T.officinale(TO),showing more growth vigor and coexistence with TKS in wild habitats,pose a challenge to germplasm collection and commercial planting of TKS in the future.In order to identify these species at the molecular level and investigate their population structure and evolution,three chloroplast(trnH-psbA,petL and ycf1)and one nuclear(ITS2)DNA barcodes were screened on wild collections of 10 TKS,2 TB and 2 TO.ITS2 and trnH-psbA exhibited high interspecies and low intra-specific variation,therefore suitable for differentiating Taraxacum species but inappropriate for examining intra-specific population structure.In comparison,petL and ycf1 revealed zero or near zero inter and intra-specific genetic distance and were thus excluded as useful DNA barcodes in Taraxacum species.Furthermore,phylogenetic tree analysis based on ITS2 and trnH-psbA sequences showed that TB might have evolved from the hybrid offspring of TKS(Maternal)and TO(Paternal).The study provides reference for the next step to studyTKS germplasmresources.

关 键 词：蒲公英 橡胶草 DNA条形码 ITS2 系统进化 

分 类 号：S576[农业科学—作物学]