贵州喀斯特山区野生葛藤根瘤菌的资源利用

Rhizobia of Pueraria lobota in Karst Mountainous Area of Guizhou and the Resource Utilization

为获得固氮促生能力强、寄主识别范围广的高效抗逆葛藤根瘤菌。本试验收集贵州省16个县(市)5个不同生态功能区的葛藤根瘤样品,经分离纯化、16 S rRNA基因序列比对、区系分析以及百脉根盆栽回接筛选获得高效抗逆葛藤根瘤菌。结果表明,分离纯化获得39株根瘤菌分属于7属17种,区系分析优势属为慢生根瘤菌属(Bradyrhizobium)和假单胞菌属(Pseudomonas),分布频率均高达24.39%;优势种为根癌土壤杆菌(Agrobacterium tumefaciens)和豆根瘤菌(Rhizobium leguminosarum),发生频率相对较高,分别达14.63%和12.20%。盆栽回接筛选获得14株优良促生固氮葛藤根瘤菌,其中分离自荔波县驾欧乡的LJPR 58-1与宿主植物的共生结瘤及促生长率均与另外13个优良菌株差异显著(p<0.05),为最优固氮根瘤菌。

The purpose of this study was to screen and obtain a high-efficiency, resistant Pueraria lobota rhizobia with strong nitrogen-fixing and growth-promoting ability and a wide range of host recognition. The root nodules samples of Pueraria lobota from 16 counties(cities) in 5 different ecological functional areas in Guizhou Province were collected, and the Pueraria lobota rhizobia were obtained by isolation and purification, 16 S rRNA gene sequence alignment, floristic analysis, and back connection screening of L. japonicus. Thirty-nine rhizobia strains were isolated and purified, belonging to 7 genera and 17 species. The dominant genera in floristic analysis were Bradyrhizobium and Pseudomonas, with a distribution frequency of 24.39%. The dominant species were Agrobacterium tumefaciens and Rhizobium leguminosarum had a relatively high frequency of 14.63% and 12.20%, respectively. 14 strains of excellent growth-promoting nitrogen-fixing Pueraria lobota rhizobia were obtained from potted back graft screening, among which LJPR 58-1 isolated from Jiaou Township, Libo County had significant differences in symbiotic nodulation and growth-promoting rates with the other 13 excellent strains(p<0.05), which was the best nitrogen-fixing rhizobia.