3株抗水稻和荔枝病原菌的海洋真菌的分离鉴定

本研究采用平板对峙法和菌丝块法测定分离自广西北部湾的3株海洋真菌MF-3、MF-6和MF-13的抗荔枝和水稻病原菌抗菌活性,并通过形态学观察结合分子生物学方法鉴定其分类地位。结果表明,当采用平板对峙法时,3株海洋真菌对荔枝霜疫霉、炭疽病菌、水稻纹枯病菌和水稻稻瘟病菌等4种指示菌的菌丝生长均有强的抑制作用;菌丝块法试验结果发现3株真菌的发酵液均对荔枝霜疫霉菌有很好的抑制效果,菌丝相对生长抑制率分别达到94.29%、98.16%和86.37%,对水稻纹枯病病原菌抑制效果次之,其菌丝相对生长抑制率达到80%左右;其中,MF-3菌株对荔枝霜疫霉、炭疽菌、水稻纹枯病菌和水稻稻瘟病菌都有较好的抑制作用,MF-6对霜疫霉、水稻纹枯病菌和水稻稻瘟病菌也有较好的抑菌效果和广谱性。结合形态学观察和ITS rDNA序列比对分析,初步将MF-3鉴定为布雷正青霉（Eupenicillium brefeldianum）,MF-6为微紫青霉（Penicillium janthinellum）,MF-13为短棒曲霉（Aspergillus clavatonanicus）。耐盐度试验结果表明这3株真菌是适应海洋环境的兼性海洋真菌。该3株海洋真菌表现的抗真菌活性,对应用于荔枝或水稻病害的生物防治和新型农药的研发有潜在的应用价值。

Isolation and Identification of 3 Strains of Marine Fungi with Antagonistic Ability Against Litchi and Rice Pathogenic Fungi

Biocontrol effects against phytopathogens from lichi and rice of 3 strains of marine-derived fungi,MF-3,MF-6 and MF-13 isolated from Beibu Gulf in Guangxi of China,was evaluated by the method of confronting cultures and metabolites plate culture on PDA plates,subsequently,the taxonomic status was probed morphologically and molecularly.Results showed that the 3 strains performed a high level of antagonistic activity toward a broad spectrum to all 4 tested phytopathogens,Peronophythora litchi,Colletotrichum gloeosporioides Penz.,Rhizoctonia solani and Pyricularia oryzae Cav.and the exploration of 3 strains fermentation in Erlenmeyer flask which were used as inhibitors to control the growth of pathogenic fungi also showed that the 3 strains had high activity against the mycelial growth of Peronophythora litchi,with an inhibitory rate of 94.29%,98.16% and 86.37% respectively,followed by inhibitory effect on Pyricularia oryzae Cav.with an inhibitory rate of about 80%,in which MF-3 strain displayed a broad-spectrum inhibitory activity to 4 tested phytopathogens primely,MF-6 rep-resented the same antimicrobial effect except Colletotrichum gloeosporioides Penz..After observation on the morphology and molecular biology appraisal as well as IRS rDNA sequence,MF-3、MF-6 and MF-13 were identified as Eupenicillium brefeldianum,Penicillium janthinellum and Aspergillus clavatonanicus.According to the salinity tolerance test,all of the 3 strains are facultative marine fungi adapted to the harsh marine environment.The antimicrobial activity against fungi of the 3 marine fungi has potential value to the development of agricultural chemicals for controlling lichee or rice diseases.