草业学报2019，Vol.28Issue(2)：88-101,14.DOI:10.11686/cyxb2018160
紫花苜蓿根瘤菌分子分型和生物型划分研究
Molecular typing and biotype classification of rhizobia of Medicago sativa
摘要
Abstract
This study aimed to classify biotypes in the same rhizobium species according to their phenotypic characteristics and the symbiotic efficiency between the alfalfa variety and rhizobium strain, and so to provide a knowledge base for breeding rhizobia that are effective symbiotic partners with alfalfa.Rhizobium strains were isolated from different plant parts of five Medicago sativa varieties in three cultivation regions of Gansu province.16 SrRNA sequencing, multilocus sequence typing (MLST), numerical taxonomy analysis based on phenotypic characteristics and symbiotic efficiency determination were used to achieve rhizobia biotype classification.Of 78 rhizobia strains in a preliminary screening, 20 were assigned to Rhizobium radiobacter by 16 S rRNA sequencing and MLST analysis.Seven phenotypic clusters were formed based on numerical taxonomy analysis of phenotypic characteristics.Seedlings of the five M.sativa varieties were inoculated with the 20 R.radiobacter strains, and shoot dry weights, which contributed the most to the symbiotic efficiency between alfalfa and rhizobium, for varieties inoculated with each strain were compared using Duncan's multiple range test.The symbiotic efficiency of strains was designated A, B, or C when the shoot dry weight of inoculated plants was, respectively, significantly higher than, not significantly different from, or significantly lower than that of non-inoculated control plants.The designated symbiotic efficiency of each rhizobia was combined according to the order of M.sativa cv.Gannong No.3, Gannong No.9, Longzhong, Qingshui, and WL168 HQ, and six kinds of symbiotic combination patterns were formed.The 20 R.radiobacter strains were divided into 14 biotypes according to phenotypes and symbiotic patterns.For M.sativa cv.WL168 HQ, Gannong No.3, and Longzhong many rhizobium biotypes were found, while the rhizobia of M.sativa cv.Gannong No.9, and Qingshui were monotypic.In conclusion, rhizobia of the same species (R.radiobacter) could be classified into biotypes using information on phenotypic characteristics and symbiotic patterns, and some alfalfa varieties were found to host a number of rhizobium biotypes.关键词
紫花苜蓿/根瘤菌/分子分型/共生模式/生物型Key words
Medicago sativa/rhizobium/molecular typing/symbiotic pattern/biotype引用本文复制引用
康文娟,师尚礼,苗阳阳..紫花苜蓿根瘤菌分子分型和生物型划分研究[J].草业学报,2019,28(2):88-101,14.基金项目
国家现代农业产业技术体系(CARS-34) （CARS-34）
国家自然科学基金项目(31560666)资助 （31560666）
