内生球毛壳属真菌CEF-082对棉花黄萎病的控制作用

 内生真菌在生物防治上具有很大的应用潜力,本研究旨在明确棉花内生真菌球毛壳菌(Chaetomium globosum)CEF-082对黄萎病菌(Verticillium dahliae)的拮抗作用及对黄萎病(Verticillium wilt)的防治效果。采用圆盘滤膜法、凹玻片法等测定CEF-082对棉花黄萎病菌的抑制效果;温室采用滤液接种法和基质接种法测定其对棉花黄萎病的防治效果;并采用实时定量PCR检测棉株内防御基因的表达及黄萎病菌的含量。结果表明,CEF-082的非挥发性代谢物对棉花黄萎病菌菌落生长的抑制率为100%,对分生孢子产量的抑制率为70.5%,试验浓度范围内对分生孢子萌发没有明显抑制作用;棉苗预接种CEF-082培养滤液或将CEF-082的玉米沙粒培养物接入基质中再种植棉花,对黄萎病的防治效果分别为62.37%和66.88%;这两种处理对棉花的生长发育没有副作用,且后者对出苗有促进作用;荧光定量PCR结果表明,CEF-082代谢产物显著提高了棉花防御基因苯丙氨酸解氨酶基因(pal)、过氧化物酶基因(pod)和多酚氧化酶基因(ppo)以及β-1,3-glucanase基因的表达量,抑制了黄萎病菌在棉株体内的繁殖。棉花内生真菌CEF-082可以有效地防治棉花黄萎病,其作用机理主要有抗生作用和诱导抗性,在棉花黄萎病防治上具有较好的应用前景。

Control effect of endophytic fungus Chaetomium globosum CEF-082 against Verticillium wilt in Gossypium hirsutum

Endophytic fungi have great potential in biological control, and the objective of this study is to explore antagonistic action of endophytic fungus Chaetomium globosum CEF-082 against Verticillium dahliae and its control effect against Verticillium wilt of cotton. The inhibition rate of CEF-082 aganist V. dahliae was assessed using the exudate filtering method and concave slide method, and the control effect of C. globosum on cotton Verticillium wilt were detected by culture filtrate (CF) inoculation and substrate inoculation methods in greenhouse. In addition, the expression level of defense genes and DNA content of V. dahliae in Gossypium hirsutum were detected by real-time quantitative PCR. The results showed that the inhibition rate of non-volatile metabolites of CEF-082 on the colony growth of V. dahliae was 100%, and on conidial yield was 70.5%. However, obvious inhibitory effect of CEF-082 on conidial germination was not detected. When cotton seedlings were pro-inoculated with CEF-082 CF or substrate containing CEF-082 in greenhouse, the inhibition rates were 62.37% and 66.88%, respectively. These two treatments had no negative effect on the growth of cotton, and the latter treatment promoted seedling emergence. In addition, fluorescence quantitative PCR results showed that CEF-082 metabolic products significantly increased the expression of cotton defense genes including pod, ppo, pal and β-1,3-glucanase, and inhibited the multiplication of V. dahliae in G. hirsutum. Endophytic fungus CEF-082 in G. hirsutum can effectively control Verticillium wilt, and its action mechanisms include antibiotic effect and induced resistance of host plant. Taken together, our findings suggest that endophytic fungus CEF-082 has great potential in controlling cotton Verticillium wilt.