粮食上木霉菌的分离鉴定及其生防效果

【背景】粮食在生长和收储期极易受到病原真菌或产毒真菌的污染，造成严重的损失。众多实践证明木霉属(Trichoderma)可以有效防治植物病原真菌。【目的】鉴定和筛选能有效抑制粮食常见危害真菌的木霉生防菌株，开发生防菌剂，保障粮食生产安全。【方法】从粮食上分离筛选出35株木霉，通过多基因系统发育分析和形态学观察方法进行菌种鉴定，利用平板对峙试验筛选出对粮食常见危害真菌有抑制作用的菌株。【结果】35株木霉分属于8个种，分别为非洲哈茨木霉(Trichodermaafroharzianum)、类棘孢木霉(Trichodermaasperelloides)、 Trichoderma amoenum、近深绿木霉(Trichoderma paratroviride)、Trichoderma obovatum、长枝木霉(Trichoderma longibrachiatum)、东方木霉(Trichodermaorientale)和深绿木霉(Trichodermaatroviride)。对峙试验结果表明，这8种木霉对于粮食上分离到的10种危害真菌均具有较好的抑制效果。非洲哈茨木霉(T.afroharzi...

Isolation, identification, and biocontrol efficacy determination of Trichoderma spp. on grains

Background] Grains are easily contaminated by pathogenic fungi and toxigenic fungi during the growth, harvest, and storage stages, which results in serious losses. Practices and studies have proved that the pathogenic fungi of plants can be controlled effectively by Trichoderma species. Objective] To identify and screen the strains for the biocontrol of Trichoderma on grains and develop biocontrol fungicides for ensuring grain security.Methods] In this study, 35 strains of Trichoderma were isolated from grains. They were identified based on both multi-gene phylogenetic relationship and morphological characteristics. Plate confrontation experiments were conducted to select the strains with antagonistic effects on common deleterious fungi. Results] Eight species of Trichoderma were identified, including Trichoderma afroharzianum, Trichoderma asperelloides, Trichoderma amoenum, Trichoderma paratroviride, Trichoderma obovatum, Trichoderma longibrachiatum, Trichoderma orientale, and Trichoderma atroviride. The antagonistic assay demonstrated that these eight Trichoderma species had antagonism on 10 deleterious fungal species from grains. The antifungal efficacy of T. afroharzianum and T. longibrachiatum was better than that of other species. The a91 strain of T. afroharzianum showed the best antifungal efficacy, with the inhibition rates more than 65% against 9 deleterious fungal species. Conclusion] The Trichoderma strains screened out in this study have great application potential for biocontrol and strong inhibitory effect on common pathogenic fungi and toxigenic fungi isolated from grain crops.