摘要
以四川盆地大豆根瘤为材料,采用划线法分离内生细菌、16S rDNA PCR-RFLP分析其遗传多样性,并结合菌株促生特性和盆栽试验筛选优良促生菌.从分离获得的130株内生细菌中选取了40株细菌作为供试菌株,16S rDNA序列表明分属于芽孢杆菌属(Bacillus)、肠杆菌属(Enterobacter)、假单胞菌属(Pseudomonas)、中华根瘤菌属(Sinorhizobium)和慢生根瘤菌属(Bradyrhizobium).以大豆为供试作物筛选出了12株具有促生能力的细菌,所有菌株均能分泌吲哚-3-乙酸(IAA),浓度达到0.353-32.404μg/mL;7株能产铁载体,活性单位为7.35%-34.31%;有11株具有溶磷能力,溶磷量达到4.26-10.6μg/mL;6株具有固氮能力.接种12株供试菌株后,玉米的农艺性状、植株全氮和全磷含量均优于单施化肥处理,其中菌株DA16-5效果最好,表现出良好的促生潜力.综上,四川盆地大豆根瘤内生菌遗传多样性丰富并且普遍具有促生能力,是重要的生物资源.
This research aimed to determine the systematic classification of soybean nodules endophytes and to isolate efficient plant growth-promoting bacteria（PGPB）. We took the soybean nodules in Sichuan Basin as samples to isolate endophytes by plate streaking. 16S rDNA PCR-RFLP and 16S rDNA sequence analysis were applied to explore the genetic diversity. Plant growth-promoting characteristics and the results of pot experiments were used to sort out efficient PGPB. A total of 130 endophytic bacteria were isolated and 40 representative strains were selected. The 16S rDNA sequences showed that these strains belonged to Bacillus, Enterobacter, Pseudomonas, Sinorhizobium and Bradyrhizobium. Among them, 12 plant PGPBs were screened using soybean as target plant in pot experiment, and their PGP characteristics were performed. The results showed that all the 12 isolates could produce Indole-3-acetic Acid（IAA） with concentration ranging from 0.353 to 32.404 μg/mL; 7 isolates were siderophores producers with the siderophores activity unit as 7.35%-34.31%; 11 isolates were able to solubilize phosphate with the concentration of phosphorus in liquid culture reaching 4.26-10.6 μg/mL; and 6 isolates had nitrogen fixing ability. Furthermore, their plant growth promoting capacity to corn was evaluated by pot experiments, the results showed that the total plant N and P content and agronomic characteristic index of corns inoculated with the 12 PGPB strains was better than that under fertilization treatment, with significant plant growth promotion effect of strain DA16-1-5 on both soybean and corn. Hence DA16-1-5 had good plant promoting growth potential. The results showed that endophytic bacteria isolated from soybean root nodules in Sichuan Basin have abundant genetic diversity with plant growth promoting activity, therefore they are important biological resources.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2017年第1期46-53,共8页
Chinese Journal of Applied and Environmental Biology
基金
国家科技支撑计划项目(2012BA D14B18)
四川省科技支撑计划项目(2014NZ0044)资助~~
关键词
大豆根瘤
内生细菌
16S
RDNA
遗传多样性
促生能力
soybean nodule
endophytic bacteria
16S rDNA
genetic diversity
plant growth promotion ability
