针对新疆红提葡萄中分离的生防菌株——毕赤酵母G5,以葡萄灰霉菌(Botrytis cinerea)为靶标菌,研究了G5对葡萄灰霉菌孢子及对葡萄果实内5种关键酶活性的影响,初步探讨了G5拮抗葡萄采后灰霉病的机理.采用离体(in vitro)实验与活体(in vivo)实验的方法对毕赤酵母菌G5拮抗葡萄灰霉病的机理进行探究.结果发现,毕赤酵母菌株G5对葡萄灰霉菌孢子的萌发和菌丝生长均有抑制作用,对灰霉菌丝的抑制率最高为80.20%,对灰霉孢子抑制率达86.89%;两者间存在营养竞争关系,有重寄生现象产生,拮抗菌自身并不分泌抗菌物质.此外,该菌株能诱导果实体内过氧化物酶、多酚氧化酶、苯丙氨酸解氨酶、几丁质酶、β-1,3-葡聚糖酶的酶活性,使其酶活性有显著提高,说明毕赤酵母G5可以有效的诱导果实内抗病相关酶的活性,增强对灰霉病的抑制效果.毕赤酵母G5拮抗葡萄灰霉病的机理主要包括营养竞争、诱导抗病性,是否有重寄生作用还需要进一步验证.%Considering the Pichia pastoris G5,a biocontrol strain isolated from red grape in Xinjiang and using Botrytis cinerea as target strain,we studied the effects of G5 on the spore of B. cinerea and the activities of five enzymes in the red grape fruit,and primarily explored the antagonistic mechanisms of G5 against B. cinerea by in vitro and in vivo experiment. Results showed that the G5 obviously inhibited the germination of B. cinerea spores and the growth of mycelium,and the rate of inhibiting mycelium maximally reached 80.20% and the rate of inhibiting spore germination was 86.89%. Nutritional competition existed between the G5 and B. cinerea. In the course of antagonism,the heavy parasitism phenomenon occurred. Experiment sindicated that G5 itself did not secrete antimicrobial substances. In addition,the strain induced and significantly increased the enzymes'activities in fruit,such as peroxidase,polyphenol oxidase,phenylalanine ammonia lyase, chitinase,and β-1,3-glucanase. The inhibition mechanisms of G5 to B. cinerea include nutrition competition and inducible resistance ;whether or not there is heavy parasitism needs to be further validated.
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