解淀粉芽胞杆菌PHODG36的解磷、促生及防治马铃薯黑痣病的功能分析

Functional analysis of Bacillus amyloliquefaciens PHODG36 on phosphate-solubilizing,growth-promoting activity and control efficacy on potato black scurf

为筛选兼具高效溶磷和抑菌防病作用的多功能细菌,本试验采用溶磷圈法结合钼锑抗法对作物根围土壤中的解磷菌进行筛选和平板对峙法测定解磷菌株对马铃薯主要病原菌的抑制能力;通过盆栽试验评价解磷菌株对马铃薯的促生作用和对马铃薯黑痣病的防治效果以及形态特征、Biolog微生物鉴定系统及多基因序列(16S rDNA以及gyrA、gyrB、rpoB和rpoC)分析对解磷菌株进行分类鉴定。结果表明,PHODG36菌株表现高效解无机磷活性,其溶磷量为79.7 mg/L;该菌株对5种马铃薯病原菌均具有抑制作用,其中对马铃薯黑痣病菌的抑菌率最高,达69.6%;浇施该菌株发酵液(菌含量5×10^(8) CFU/mL)后,对马铃薯幼苗有明显的促生作用,株高、地上鲜重和干重、根鲜重和干重较对照分别增加178.3%、509.8%、396.9%、160.4%和146.4%,同时对马铃薯黑痣病有显著防效,达56.8%;经鉴定PHODG36菌株为解淀粉芽胞杆菌(Bacillus amylolique-faciens)。PHODG36菌株兼具解磷、促生及防病等多种重要作用,可应用于防病增产多功能微生物产品的产业化开发。

In order to screen multifunctional bacteria with efficient phosphate solubilizing and antagonistic activity,phosphorus solubilizing bacteria were screened by the method of halo ring and Mo-Sb colorimetry from rhizosphere soil.The antagonism activity to various potato disease pathogens was determined by plate confrontation method.The growth-promoting effect of excellent bacteria strain on potato and the control efficacy on potato black scurf were evaluated by pot experiment.The strain was identified by morphological characters,Biolog Microbiological Identification System and 16S rDNA sequence,as well as phylogenetic tree constructed with multiple genes of gyrA,gyrB,rpoB and rpoC.We isolated a strain PHODG36 with high P-solubilizing activity whose soluble phosphorus content in the fermentation broth reached 79.7 mg/L.Strain PHODG36 exhibited strong antifungal activities against five kinds of potato disease pathogens,and the antagonism rate against Rhizoctonia solani was 69.6%.Application 8 of the fermentation broth of strain PHODG36(5×10^(8)CFU/mL)promoted the growth of potato seedlings obviously.The plant height,aboveground fresh and dry weight and root fresh and dry weight of potato increased by 178.3%,509.8%,396.9%,160.4%and 146.4%,respectively,compared with that of the control.Meanwhile,the control efficacy on potato black scurf reached to 56.8%.Strain PHODG36 was identified as Bacillus amyloliquefaciens.B.amyloliquefaciens PHODG36 was found to be able to dissolve insoluble phosphate to promote the growth of potato seedlings and control potato black scurf.Therefore,it is recommended for the industrial development of microbial fertilizer and pesticides.