论文部分内容阅读
从来自烤烟品种NC297的970株内生细菌中,以烟草黑胫病菌(Phytophthora parasitica var.nicoti-anae)为靶标,共筛选出165株拮抗菌,这些内生细菌对黑胫病菌的抑菌率在9.55%～55.96%之间.内生细菌的生物量在苗期、团棵期、开花期和成熟期中无显著差异,但拮抗菌数量呈上升趋势.对165株拮抗菌的16SrRNA基因序列进行RFLP分析共产生12种带型.根据RFLP带型选取41株进行16S rRNA基因序列测定和系统发育分析.结果表明这165株生防内生细菌归于3大类群:Proteobacteria,Actinobacteria和Firmicutes.Firmi-cutes类群中的芽孢杆菌属(Bacillus)是优势属,共6种RFLP带型,159个菌株,包括Bacillus amyloliquefacienssubsp.plantarum,Bacillus methylotrophicus,Bacillus tequilensis,Bacillus aryabhattai,Bacillus cereus和Bacillus my-coide.Bacillus amyloliquefaciens subsp.plantarum和Bacillus.methylotrophicus是Bacillus中分离频率最高的2种内生拮抗菌,共149株,占该属菌株数的90.30%.其余6个菌株分别属于6个种:Brevibacillus reuszeri,Streptomycesfinlayi,Streptomyces atroolivaceus,Erwinia rhapontici,Enhydrobacter aerosaccus和Stenotrophomonas rhizophila.
Among 970 endophytic bacteria from tobacco cultivar NC297, 165 antagonistic bacteria were screened out against Phytophthora parasitica var. Nicoti-anae. The antibacterial activity of these endophytic bacteria against Phytophthora parasitica Between 9.55% and 55.96% .The biomass of endophytic bacteria showed no significant difference at seedling stage, boll stage, flowering stage and mature stage, but the number of antagonistic bacteria was on the rise.The sequence of 16S rRNA gene of 165 antagonistic bacteria RFLP analysis produced a total of 12 bands.According to the RFLP banding 41 strains were selected for 16S rRNA gene sequence analysis and phylogenetic analysis.The results showed that the 165 strains of endophytic bacteria belong to three groups: Proteobacteria, Actinobacteria and Firmicute.Firmi- Among the cutes, Bacillus is the dominant genus, and there are 6 RFLP bands and 159 strains including Bacillus amyloliquefacienssubsp.plantarum, Bacillus methylotrophicus, Bacillus tequilensis, Bacillus aryabhattai, Bacillus cereus and Bacillus my-coide.Bacillus amyloliquefaciens subsp.plantarum and Bacillus.methylotrophicus are the two endophytic antagonistic bacteria with the highest frequency in Bacillus, accounting for 149 strains, accounting for 9 0.30% .The remaining six strains belong to six species: Brevibacillus reuszeri, Streptomycesfinlayi, Streptomyces atroolivaceus, Erwinia rhapontici, Enhydrobacter aerosaccus and Stenotrophomonas rhizophila.