烟草黑胫病拮抗真菌的筛选及活性评价

为获得更多防治烟草黑胫病的拮抗真菌，从烟草黑胫病发病烟株根际土壤分离20株真菌，通过平板对峙法筛选，发现菌株ZP2-1、ZP2-3、ZP2-4、GZ3、GZ7对烟草黑胫病菌具有较好的抑制效果。形态学和分子生物学分析表明，ZP2-1为里氏木霉（Trichoderma reesei）、ZP2-3为拟康宁木霉（Trichoderma koningiopsis）、ZP2-4为黑曲霉（Aspergillus niger）、GZ3为烟曲霉（Aspergillus fumigatus）、GZ7为红棕肉座菌（Hypocre rufa）。ZP2-4具有较强分泌纤维素酶和蛋白酶的能力且固体发酵产孢能力显著（p<0.01）高于其余4株菌。ZP2-1、GZ3、ZP2-4固态发酵产物纤维素酶活性相当且显著（p<0.01）高于ZP2-3和GZ7。田间试验结果显示，ZP2-1、GZ3、ZP2-4对烟草黑胫病田间防治效果分别为59.50%、61.82%、85.00%。

Selection and Field Evaluation of Antagonistic Fungi against Tobacco Black Shank

In order to obtain more antagonistic fungi for prevention and control of tobacco black shank, 20 fungal strains were isolated from tobacco rhizosphere soil, among which ZP2-1, ZP2-3, ZP2-4, GZ3, and GZ7 had antagonistic effects on Phytophthora nicotianae. Molecular and morphological analysis showed that these strains were identified as Trichoderma reesei ZP2-1, Trichoderma koningiopsis ZP2-3, Aspergillus niger ZP2-4, Aspergillus fumigatus GZ3 and Hypocre rufa GZ7. ZP2-4 has a strong ability to secrete cellulase and protease and the ability of sporulation in solid fermentation was higher than that of the other 4 strains (p<0.01). The cellulase activities of the solid fermentation products of ZP2-1, GZ3 and ZP2-4 were fairly high and significantly higher than that of ZP2-3 and GZ7 (p<0.01). ZP2-1, GZ3 and ZP2-4 with high spore producing ability and cellulase activity in solid fermentation were selected for field trial. The results showed that the control efficiency against tobacco black shank of ZP2-1, GZ3 and ZP2-4 were 59.50%, 61.82% and 85.00%, respectively.