桂西北喀斯特常见豆科植物根瘤菌的遗传多样性  

Genetic diversity of rhizobia isolated from common legumes in the Karst area,Northwest Guangxi

作　　者：刘璐[1,2,3] 何寻阳[1,2] 谢强[4] 王克林[1,2] 

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [2]中国科学院环江喀斯特生态系统观测研究站,广西环江547100 [3]中国科学院大学,北京100049 [4]广西师范大学,广西桂林541004

出　　处：《应用生态学报》2015年第12期3663-3669,共7页Chinese Journal of Applied Ecology

基　　金：中国科学院"西部行动计划"项目(KZCX2-XB3-10)资助

摘　　要：调查了桂西北喀斯特24种常见豆科植物的结瘤情况及特征,并从15种宿主植物上获得39份根瘤样品提取根瘤基因组DNA,扩增16S rDNA和nifH基因,构建系统发育树,对根瘤菌遗传多样性进行了研究.结果表明:有15种豆科植物是结瘤的,其中14种为蝶形花亚科,1种为含羞草亚科,而云实亚科未发现结瘤.一些本应结瘤的植物未发现根瘤,可能与喀斯特土壤的保水性差有关.BLAST和系统发育分析结果均显示,来源于多种豆科植物的根瘤菌均归属于慢生根瘤菌属,仅有2个亮叶崖豆藤样品的根瘤菌归属于中慢生根瘤菌属.在系统发育树上来源于同一地点或同一宿主植物的根瘤序列均表现出一定的聚集性,说明共生根瘤菌的种类可能受宿主植物及所处生态环境的共同影响.Legumes,with a strong resistance to the adverse environmental conditions,are pioneer plants in degraded habitats,and play an important role in ecosystem restoration.In this study,the nodulation characteristics of 24 legumes were surveyed in the Karst area of Northwest Guangxi.A total of 39 nodule samples were collected from 15 legumes,the DNA was extracted and the 16 S rDNA and nifH gene were amplified.A phylogenetic tree was then constructed to analyze the genetic diversity of rhizobia.The results showed that 15 legumes were nodulated,of which 14 belonged to the Papilionoideae,one to the Mimosaceae,and none to the Caesalpinoideae.No nodules were found on some legumes that were reported as nodulated,which might result from soil water stress in Karst.BLAST result and phylogenetic analyse indicated that most of the legumes were associated with rhizobia that belonged to the genus Bradyrhizobium,with the exception of two samples from Callerya nitida that were associated with the genus Mesorhizobium.In the phylogenetic tree,the sequences obtained from the same plot or the sequences from the same host species clustered together in most cases.This finding suggested that host selection and the ecological environment are the major factors that influence the genotype of rhizobia.

关 键 词：系统发育树 根瘤菌 16S r DNA nif H 豆科植物 喀斯特 

分 类 号：Q939.114[生物学—微生物学]