摘要
为提高豆科决明属(Chamaecrista spp.)牧草的结瘤能力和固氮效率,促进决明属牧草在酸性土壤中的应用及推广,本研究以圆叶决明(Chamaecrista rotundifolia)和羽叶决明(Chamaecrasta nictitans)为试验材料,通过分离、纯化、nodA基因鉴定等方法,从酸性土壤里决明属牧草的根瘤中分离到10株候选根瘤菌株系。16S rDNA测序及系统发育树分析表明,这10株根瘤菌均属于慢生型根瘤菌。回接试验表明,上述10株根瘤菌均能与圆叶决明共生,形成根瘤。与不接种的对照相比,其固氮酶活性为0.08~4.65μmol·g^-1·h^-1,植株干重、SPAD值和氮含量分别提高了99.17%~372.14%,399.27%~789.05%,235.00%~1043.33%。其中,4株根瘤菌TXR2,TXN1,WYSR1,JYN6对圆叶决明氮营养贡献最大,并且TXN1与宿主共生形成的根瘤数目最多,而JYN6的固氮酶活性最高。说明本研究分离鉴定到4株决明高效根瘤菌,具有较好的应用前景。
In order to enhance the capacity of nodulation and nitrogen fixation of Cassia(Chamaecrista spp.),and to further promote its application and extension in acidic soils,Chamaecrista rotundifolia and Chamaecrasta nictitans were used in this study to screen effective rhizobial strains.10 candidate rhizobial strains were isolated from the nodules of Cassia pastures from acid soils through isolation,purification,nodA gene identification,etc.The results from 16S rDNA gene sequencing and phylogenetic tree analysis showed that all these 10 rhizobial strains belonged to bradyrhizobium sp.Moreover,the re-inoculation experiment indicated that all the 10 candidate rhizobial strains were able to establish symbiosis with Cassia rotundifolia to form nodules.Compared with non-inoculated plants,the nitrogenase activity was 0.08~4.65 mol·g^-1·h^-1,and the dry weight,SPAD value and nitrogen content of the plants increased by 99.17%~372.14%,399.27%~789.05%,and 235.00%~1043.33%,respectively.Among them,4 rhizobial strains including TXR2,TXN1,WYSR1 and JYN6 displayed the largest contribution to the improvement of nitrogen nutrition in Cassia rotundifolia,and the symbiosis of TXN1 and host plant could produce the largest number of nodules while the highest nitrogenase activity was found after inoculation with JYN6.These results suggest that 4 effective rhizobial strains were isolated and identified,which has great application prospects.
作者
杨庆
王义祥
李欣欣
翁伯琦
廖红
YANG Qing;WANG Yi-xiang;LI Xin-xin;WENG Bo-qi;LIAO Hong(Root Biology Center,College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian province 350002, China;Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain, Fuzhou, Fujian Province 350003, China)
出处
《草地学报》
CAS
CSCD
北大核心
2020年第6期1519-1526,共8页
Acta Agrestia Sinica
基金
农业部“茶树根系养分高效改良及应用创新团队”项目资助。
关键词
决明属牧草
酸性土壤
根瘤菌
分离
鉴定
Cassia pasture
Acidic soils
Rhizobia
Isolation
Identification
