基于DNA条形码的向日葵田弯管列当种群遗传多样性研究  

Genetic diversity of Orobanche cernua Loefling populations in sunflower fields based on DNA barcoding

作　　者：张毅笑 魏守辉[1] 姜翠兰 黄兆峰[1] 苏杰天 孟帅帅 云晓鹏 白全江 吴文龙 黄红娟[1] ZHANG Yixiao;WEI Shouhui;JIANG Cuilan;HUANG Zhaofeng;SU Jietian;MENG Shuaishuai;YUN Xiaopeng;BAI Quanjiang;WU Wenlong;HUANG Hongjuan(Institute of Plant Protection,Chinese Academy of Agricultural Sciences,Beijing100193,China;Institute of Plant Protection,Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences,Hohhot010031,China)

机构地区：[1]中国农业科学院植物保护研究所,北京100193 [2]内蒙古农牧科学院植物保护研究所,呼和浩特010031

出　　处：《植物保护》2022年第2期24-32,47,共10页Plant Protection

基　　金：科技部科技基础性工作专项(2013FY113200);国家特色油料产业技术体系(CARS-14-1-21)。

摘　　要：弯管列当是危害我国向日葵最严重的寄生杂草。为了明确我国向日葵田弯管列当种群的遗传多样性,本试验利用rbcL、matK、ITS2条形码序列对采自我国向日葵主产区的58份弯管列当样品进行PCR扩增及测序,采用Vector NTI软件对测序结果进行剪切比对,利用MEGA 6.0软件计算种内遗传距离并构建系统发育树。利用扫描电镜观察其种子的显微形态特征。结果表明,3个DNA条形码序列中仅ITS2片段扩增测序结果理想并表现出较好的聚类结果。各样品ITS2序列剪切比对后长度为453 bp,种内遗传距离为0.002~0.007,通过比较各样品ITS2序列的碱基组成和差异位点,能将不同弯管列当种群区分开。ITS2聚类结果表明58份弯管列当样品聚为3类,分别为Ⅰ型、Ⅱ型和Ⅲ型。形态分类结果表明,不同类型弯管列当在植株形态、种子形状及微观形态结构等方面存在差别。由于不同弯管列当种群的生境、寄主(向日葵栽培品种)不同,其种群遗传进化差异显著。基于ITS2条形码和扫描电镜形态学观察相结合的方法可用于弯管列当种群遗传多样性研究。Orobanche cernua Loefling is the most serious parasitic weed that threats the production of sunflower in China.To clarify the genetic diversity of different O.cernua populations in sunflower fields,barcode fragments of rbcL,matK and ITS2 were used for PCR amplification and sequencing of 58 samples of O.cernua collected from main sunflower-producing areas.The sequencing results were assembled using the Vector NTI software.MEGA 6.0 was used to calculate the intraspecific genetic distance and construct phylogenetic trees.The microscopic morphological characteristics of O.cernua seeds were observed by scanning electron microscope.The results showed that,among the three DNA barcodes,only the results of amplification and sequencing of ITS2 fragments were satisfactory and showed better clustering effect.The length of ITS2 sequences after shear alignment was 453 bp.The intraspecific genetic distance was 0.002-0.007.By comparing the base composition and differential sites of ITS2 sequences of each sample,different O.cernua populations could be distinguished.The clustering results of ITS2 showed that 58 samples of O.cernua were divided into three groups,which could be classified as typeⅠ,ⅡandⅢ.The results of morphological classification showed that there were differences in plant morphology,seed shape and micro-morphological structure among different types.There were significant differences in the population genetic evolution among different O.cernua populations originated from different habitats and hosts(sunflower cultivars).The method based on ITS2 barcoding and morphological observation by scanning electron microscope could be used to study the population genetic diversity of O.cernua.

关 键 词：弯管列当 DNA条形码 ITS2序列 种子形态 遗传多样性 

分 类 号：S453[农业科学—植物保护]