【摘要】 筛选于健康大豆植株根部的4株拮抗菌,室内平板对峙试验表明,其对番茄枯萎病病原菌Fusarium oxysporum f.sp.radicis lycopersic及其他多种病原菌有广谱抑菌能力,最佳抑菌率可达51.00%~86.81%,无菌滤液及挥发性气体亦有广谱抑菌效果。盆栽试验表明,其对番茄枯萎病有良好防控效果,发病程度降低了42.33%~51.33%,而菌株SR10和SR22处理与苯菌灵的防病效果无差异。16S r RNA种属鉴定其为多粘芽孢杆菌(SR10、SR11),油菜假单胞菌(SR21)和解淀粉芽孢杆菌(SR22)。代谢特性检测表明,4株菌均能产生蛋白酶、β-1,3葡萄糖酶、HCN、IAA、SA;不分泌几丁质酶;菌株SR10、SR11和SR22能够固氮;菌株SR21能水解产生磷酸盐;菌株SR21和SR22可以产生铁载体。抗生素合成基因检测显示3株芽孢杆菌属菌株(SR10、SR11、SR22)均具有杆菌溶素基因(bac A)和脂肽基因(srf AA),菌株SR10和SR22具有伊枯草菌素A基因(itu D),菌株SR22具有丰原素基因(fen D)和芽孢菌霉素基因(bmy B);假单胞菌属菌株SR21具有藤黄绿菌素基因(plt D)、硝吡咯菌素基因(prn D)和2,4-二乙酰藤黄酚基因(phl D)。更多还原

【Abstract】 The authors tested the inhibition rates of four antagonistic bacteria isolated from healthy soybean roots against as many as nine fungi by in vitro tests and potting experiments in greenhouse. Results showed that all strains exhibited great inhibitory effects on growth of the fungi, with inhibition rates between 51.00%—86.81%; Similar antagonistic abilities were also detected from the cell-free solutions and volatiles. Application of peat formulation of strains SR10 and SR22 to tomato roots prior to transplanting into potting medium infested with Fusarium oxysporum f. sp. radicis lycopersici provided great protection from wilt disease under greenhouse conditions, and the disease severity were reduced by 42.33%—51.33% and no difference in comparison with the chemical treatment. Analysis of 16 S r RNA indicated that SR10 and SR11 were Paenibacillus polymyxa, SR21 Pseudomonas brassicacearum and SR22 Bacillus amyloliquefaciens. All strains could produce proteases, β-1,3-glucanases, HCN, IAA, SA; SR10, SR11 and SR22 could fix nitrogen; SR21 could solubilize phosphate; SR21 and SR22 could produce siderophores; none of them could produce chitinase. PCR analysis of antibiotic biosynthetic genes confirmed that SR10、SR11 and SR22 owned the bac A and srf AA genes, both of SR10 and SR22 owned the itu D gene, SR22 owned fend and bmy B genes; SR21 owned plt D, prn D and phl D genes.更多还原