南方野生稻内生细菌的分离鉴定及促生作用

Identification and growth promotion of endophytic bacteria isolated from Oryza meridionalis

为丰富微生物肥料菌种储备库以及向菌肥菌种的选育提供依据,从南方野生稻(Oryza meridionalis)中分离纯化内生细菌,通过十二烷基硫酸钠-聚丙烯酰胺凝胶(SDS-PAGE)全细胞蛋白电泳、插入序列指纹图谱(IS-PCR)聚类分析,对分离的各类群代表菌株进行16S rRNA基因系统发育分析和鉴定,并测试代表菌株固氮、溶磷、解钾、分泌生长素和1-氨基环丙烷-1-羟酸(ACC)脱氨酶、产铁载体等促生特性.共分离到58株内生细菌,聚为11个类群.其中菌株JH40、JH50促生能力强:JH40、JH50的固氮酶活性最高,分别为360.61 nmol mL-1 h-1和494.14 nmol mL-1 h-1;JH40、JH50产吲哚乙酸能力分别为27.84 mg/L和29.97 mg/L,ACC脱氨酶活性分别为24.76μmol mg-1 h-1和22.94μmol mg-1h-1,JH40、JH50还具有溶磷和解钾能力.本研究表明南方野生稻内生菌具有丰富的遗传和功能多样性,包含多种优质促生菌,可以作为微生物肥料储备菌种,并有望在绿色农业发展中发挥促进作用.(图2表5参31)

This study was conducted to enrich the microbial fertilizer reserve bank and provide the basis for the selection of bacterial strains using Oryza meridionalis as a separation material. The endophytic bacteria were clustered by SDS-PAGE whole cell protein electrophoresis and IS-PCR fingerprints. Based on the analysis of 16 S rRNA gene sequences, the phylogenetic relationships of representative strains were determined. Experiments testing the activity of nitrogenase, phosphorus and potassium dissolution, IAA secretion, 1-aminocyclopropane-1-carboxylic acid(ACC) deaminase, and siderophore were conducted. A total of 58 endophytic bacteria were isolated. All bacteria were clustered into 11 groups. Strains JH40 and JH50 had strong growth-promoting ability. The nitrogenase activity of JH40 and JH50 were the highest, 360.61 nmol mL-1 h-1 and 494.14 nmol mL-1 h-1, respectively. IAA activity of strains JH40 and JH50 were 27.84 mg/L and 29.97 mg/L;ACC deaminase activities were 24.76 mol mg-1 h-1 and 22.94 mol mg-1 h-1, respectively. In addition, strains JH40 and JH50 could dissolve phosphorus and potassium. There are genetically diverse and functional endophytic bacteria that can be isolated from Oryza meridionalis, including some high-quality growth-promoting bacteria. The endophytic bacteria have a strong potential to promote rice growth, can be used as a microbial fertilizer reserve for bacteria, and are expected to play a catalytic role in the development of green agriculture.