昆虫肠道木霉及其对芒果炭疽病菌拮抗作用

Trichoderma spp.from insect guts and their antagonistic effects against mango anthracnose

为获得优良生防木霉菌株,本研究以昆虫肠道为样本,从中分离鉴定木霉菌株,并以芒果炭疽病菌盘长孢状刺盘孢为靶标菌,通过对峙培养、挥发性物质和非挥发性物质筛选拮抗效果最优的木霉菌株,测定其孢子悬浮液对芒果炭疽病的室内防效研究。结果显示,从105份昆虫肠道中共分离获得10株木霉,通过形态学特征和Tef1-Rpb2双基因联合建树,鉴定出长枝木霉、哈茨木霉和棘孢木霉各3株,加纳木霉1株;通过平板对峙培养显示加纳木霉HNDF-T-6对芒果炭疽病菌抑菌效果最好,其抑菌率为85.64%;其挥发性物质和非挥发性物质对菌丝生长抑制率分别为38.42%和44.01%。通过室内防效测定,经加纳木霉HNDF-T-6孢子悬浮液处理后的叶片病斑直径减少46.04%,表明该菌株对芒果炭疽病具有较好的生防潜能。

Trichoderma strains were isolated and identified from insect guts and Colletotrichum gloeosporioides was used as a target fungus in order to obtain additional biocontrol resources against mango anthracnose.Trichoderma strains with antagonistic effects on C.gloeosporioides were screened by dual confrontation culture and inhibitory effects of the volatile and non-volatile substances against the pathogen.The control effects of conidium suspension of Trichoderma on mango anthracnose was determined under laboratory condition.As a result,10 Trichoderma strains were isolated from 105 samples of insect guts,and they were identified as Trichoderma harzianum(3 strains),Trichoderma longibrachiatum(3 strains),Trichoderma asperellum(3 strains),and Trichoderma ghanense(1 strain),based on morphological characteristics and sequence analysis of Tef1-Rpb2.T.ghanense HNDF-T-6 showed the best antagonistic effects against C.gloeosporioides in dual culture(85.64%)and the inhibitory rate of volatile and non-volatile substances against mycelia growth were 38.42%and 44.01%respectively.The leaf spot diameter was reduced by 46.04%after treating with conidium suspension of T.ghanense HNDF-T-6 under indoor condition.Our results indicated that T.ghanense HNDF-T-6 has biocontrol potential against mango anthracnose.