枯草芽孢杆菌262XY2′菌剂对番茄枯萎病的预防效果及其对相关抗性生化指标的影响

Preventive effect of Bacillus subtilis 262XY2′bacterial agenton tomato fusarium wilt and its impact on biochemicalindicators of plant and rhizosphere health

【目的】以番茄为供试作物,研究枯草芽孢杆菌262XY2′菌剂对番茄枯萎病的预防效果及其对番茄植株和根际土壤生化指标的影响,以期为菌剂在农业生产制备和生物安全应用中提供理论依据。【方法】设置不同固态菌剂添加量(分别占育苗基质质量的0.5%、1.0%、2.0%、3.0%和4.0%)的试验处理组与不添加固态菌剂的对照组(CK)进行番茄育苗,番茄四叶一心后移栽至花盆进行盆栽试验,定植6周后按照病情程度分级法测定供试菌剂对盆栽番茄枯萎病的预防效果;并测定番茄植株过氧化氢酶活性、过氧化物酶活性、超氧化物歧化酶活性、几丁质酶活性和总巯基含量以及番茄根际土壤游离氨基酸含量、过氧化氢酶活性、N-乙酰-β-D-葡萄糖苷酶活性和脲酶活性等生化指标。【结果】0.5%菌剂处理的番茄根际土壤中游离氨基酸含量比CK高44.325%,N-乙酰-β-D-葡萄糖苷酶活性比CK高108.848%,过氧化氢酶活性比CK高16.472%,均为最高值;1.0%菌剂处理对番茄枯萎病的预防效果最佳,为73.485%,1.0%菌剂处理的番茄植株过氧化氢酶活性比CK高55.742%,过氧化物酶活性比CK高47.404%,超氧化物歧化酶活性比CK高39.433%,几丁质酶活性比CK高209.989%、番茄根际土壤脲酶活性比CK高12.063%,均为最高值;总巯基含量则以2.0%菌剂处理最高,比CK高191.304%。【结论】总体上,0.5%、1.0%和2.0%菌剂处理均不同程度提高了番茄防御酶活性,改善了番茄根际土壤的生化性质,3.0%和4.0%菌剂处理对番茄及其根际土壤各项生化指标影响效果不明显,甚至产生抑制作用。

【Aim】To provide a theoretical basis for the application of Bacillus subtilis in agricultural production and biosafety,this study used tomato as the experimental crop to explore the preventive effect of Bacillus subtilis 262XY2′on tomato fusarium wilt in potted plants and to evaluate its impact on biochemical indicators of tomato plants and rhizosphere soil health.【Method】Experimental groups treated with different amounts of solid bactericides(0.5%,1.0%,2.0%,3.0%,and 4.0%of seedling substrate quality)and a control check(CK)with no added solid bactericides were established for tomato seedling cultivation and four tomato plant leaves were transplanted into each pot.Six weeks after planting,the preventive effect of the tested bacteriological agent on tomato fusarium wilt was determined using an established disease severity grading method.Biochemical indicators including tomato plant catalase,peroxidase,superoxide dismutase,chitinase,catalase,N-acetyl-β-D-glucosidase,and urease activities as well as total thiol and tomato rhizosphere soil free amino acid contents were quantitated.【Result】In the rhizosphere soil of tomato treated with 0.5%bactericide,the free amino acid content and N-acetyl-β-D-glucosidase and catalase activities were 44.325%,108.848%,and 16.472%higher than those in CK,respectively.The most potent tomato fusarium wilt preventive effect was 73.485%and was achieved with 1.0%bacterial agent application.Catalase activity in tomato plants treated with 1%bacterial agent and peroxidase,superoxide dismutase,and chitinase activities were 55.742%,47.404%,39.433%,and 209.989%higher than those in CK,respectively.Rhizosphere soil urease activity was 12.063%higher than that in CK.All these represent the highest values.Total thiol content was highest with 2.0%bacterial treatment at 191.304%higher than that in CK.【Conclusion】In general,0.5%,1.0%,and 2.0%inocula increased tomato defense enzyme activities and improved biochemical properties of tomato rhizosphere soil to varying degrees.Higher density inocula(3.0%and 4.0%)exerted no notable effects on these biochemical indices of tomato plants and their rhizosphere soil and even had inhibitory effects.