甲基营养型芽胞杆菌AL7对棉花黄萎病的盆栽防治效果及定殖能力

为了探明甲基营养型芽胞杆菌AL7对棉花黄萎病的防治效果及其定殖能力,本文利用盆栽接种试验研究了菌株AL7对棉花黄萎病的防治效果;将带四环素抗性的pGFP78质粒转入到菌株AL7中,分析了菌株AL7在棉花根围土壤中、根部组织内的定殖情况。结果表明,菌株AL7对棉花黄萎病的盆栽防治效果为77.1%。pGFP78质粒转入后对菌株AL7的生长没有明显影响,仍具有游动性和产生物膜。定殖检测结果表明,菌株AL7能够在棉花根围土壤中及根系组织内长期定殖,接种5 d时定殖数量最高,达6×10~6cfu/g土,接种80 d后根围土壤中的定殖数量仍维持在2×10~6 cfu/g,根系组织内的定殖量为6×10~4 cfu/g。利用激光共聚焦显微镜观察验证,接种7 d后菌株AL7已经进入到棉花根部的中柱鞘细胞,能够在棉花根内大量定殖。

Effect of Bacillus methylotrophicus AL7 against Cotton Verticillium Wilt and Its Colonization in Rhizosphere of Cotton

The control effects of Bacillus methylotrophicus AL7 on cotton Verticillium wilt were investigated by pot experiments and its colonization ability in cotton root and rhizosphere soil was evaluated by transforming tetracycline resistance plasmid pGFP78 into AL7 and then observing by tetracycline resistance plate medium and confocal laser scanning microscope (CLSM).The results indicated that the control efficacy of strain AL7 on cotton verticillium wilt was 77.1％,with motility and the ability to produce biofilm.After transformed into strain AL7,tetracycline resistance plasmid pGFP78 has no significant negative influence on the growth of AL7.The colonization detection results showed that AL7 could colonize in cotton rhizosphere soil.Colonization peak reaches 6 × 106 cfu/g soil at five days after inoculation with AL7,and the colonization quantity reaches 2 × 106 cfu/g soil at eighty days after treatment.Strain AL7 also could colonize in cotton root organization.The colonization quantity reaches 6 × 104 cfu/g root.CLSM observation showed that the strain AL7 could also colonize into cotton root tissue with a large number at seven days after inoculation.