高产β-葡聚糖酶木霉菌诱变育种及对黄瓜枯萎病的生防效果

Mutation breeding of Trichoderma harzianum strain forβ-Glucanase production and biocontrol effect on cucumber Fusarium wilt

为提高木霉菌株的生防潜力,采用紫外线诱变与亚硝基胍处理相结合的方法,对哈茨木霉菌Th-30进行复合诱变育种,测定突变木霉菌株的β-葡聚糖酶活性及生长特性,并评价其β-葡聚糖酶诱导发酵液对盆栽和大田黄瓜枯萎病的防治效果。研究结果显示,6株突变木霉菌株产β-葡聚糖酶能力显著高于亲本菌株,其中突变菌株NU-2产β-葡聚糖酶活性较亲本菌株Th-30显著提高106.36%,且高产酶能力具有遗传稳定性。突变木霉菌株UN-2β-葡聚糖酶诱导发酵液和β-葡聚糖酶粗酶液对黄瓜枯萎病的室内盆栽防治效果分别为65.29%和63.77%,黄瓜幼苗鲜质量的增重率分别为和30.30%和22.73%。2023年UN-2β-葡聚糖酶诱导发酵液对不同生育期黄瓜枯萎病的田间防治效果分别为68.47%、71.63%、70.79%和68.65%。综上所述,与亲本菌株Th-30相比,突变木霉菌株UN-2产β-葡聚糖酶活性显著提高,其β-葡聚糖酶诱导发酵液对黄瓜枯萎病具有良好的生防效果,并对黄瓜幼苗具有明显促生作用。

In order to improve the biocontrol potential of Trichoderma harzianum strain,the combination of ultraviolet mutagenesis and Nitroso guanidine treatment was used to conduct compound mutagenesis breeding of Trichoderma harzianum Th-30.Reducing sugar method was used to determine theβ-glucanase activity of the mutant strains,and plate growth method was used to determine the growth characteristics of mutant strains.Pot experiment and field experiment were used to evaluate the control effect ofβ-glucanase fermentation broth of mutant strain on cucumber Fusarium wilt.The results showed that the ability of six mutants to produceβ-glucanase was significantly improved.The activity ofβ-glucanase induced from mutant strain NU-2 was 106.36%higher than Trichoderma harzianum Th-30,and the ability to produceβ-glucanase was genetically stable.The control effects of mutant strain UN-2β-glucanase fermentation broth and crudeβ-glucanase solution on cucumber Fusarium wilt were 65.29%and 63.77%,respectively.Strain UN-2 has a certain promoting effect on cucumber growth,with an increase rate of 30.30%and 22.73%on the fresh weight of cucumber seedlings,respectively.The field control effects of UN-2β-glucanase fermentation broth on cucumber Fusarium wilt at different growth stages of cucumber were 68.47%,71.36%,70.79%and 68.65%in 2023,respectively.To sum up,the activity ofβ-glucanase of mutant strain UN-2 was significantly improved,and itsβ-glucanase fermentation broth had a good biological control effect on cucumber Fusarium wilt,and had a significant growth promoting effect on cucumber seedlings.