2株枯草芽孢杆菌对太子参4种病原真菌的抑菌效果研究

Inhibitory effect of two Bacillus subtilis strains on four kinds of pathogenic fungi in Radix Pseudostellariae

采用枯草芽孢杆菌(Bacillus subtilis)菌株GH18和GH19对贵州省黔东南州太子参(Pseudostellaria heterophylla)的病原真菌互隔交链孢霉菌(Alternaria alternata)、博宁刺盘孢(Colletotrichum boninense)、胶孢炭疽菌(Colletotrichum gloeosporioides)和立枯丝核菌(Rhizoctonia solani)进行了抑菌效果研究。结果表明,菌株GH18和GH19对4种病原真菌都有抑菌效果,菌株GH18无细胞滤液对互隔交链孢菌孢子的抑菌效果优于GH19。菌株GH18高温杀死菌体发酵液在浓度为2.0×10~8 cfu/L和2.0×10~7 cfu/L分别处理,对互隔交链孢霉菌、博宁刺盘孢抑菌率相近。处理3d的抑菌效果优于4 d;其发酵液的抑菌率高于无细胞滤液。菌株GH18高温杀死菌体发酵液在浓度为2.0×10~8cfu/L对互隔交链孢霉菌、博宁刺盘孢抑菌效果较好,胶孢炭疽菌效果次之。因立枯丝核菌气生菌丝生长旺盛,抑菌率较低,故不适合采用生防菌GH18和GH19进行生防。

Anti-bacterial effect of Bacillus su btilis strain GH 18 and GH19 on pathogenic fungi,Alternaria arborescens,Colletotrichum boninense, Colletotrichum gloeosporioides and Rhizoctonia solani in Pseudostellaria heterophylla were studied in Qiandongnan prefecture of Guizhou province. The results showed that antibacterial rate against pathogenic fungi was similar of GH18 bacteria sterilizing solution at a concentration of 2.0 ×10^8 cfu/L and 2.0 ×10^7 cfu/L, the antibacterial effect of 3 d was better than that of 4 d, and the antibacterial effect of GH18 was better than that of GH19. Inhibition rate of fermentation broth by high temperature was higher than that of cell-free filtrate. Inhibitory effect of fermentation liquid of GH18 at high temperature with spore concentration of 2.0 ×10^8cfu/L on A. arborescens, C. boninense was better than that on C. gloeosporioides. While the inhibitory rate of R. solani was low, because of its aerial mycelium growth, which indicated that it was not a suitable bio-control target using GH18 and GH19.