杨树溃疡病生防菌株的抑菌机理研究

Antifungal mechanism of two biocontrol strains on poplar canker

黄绿木霉YGF9菌株和木贼镰刀菌LX6F2菌株分别为分离自杨树组织和杨树林土壤中的2株生防菌。为了研究黄绿木霉和木贼镰刀菌对杨树溃疡病菌葡萄座腔菌的生防抑菌机制,从生防菌株对病原菌代谢系统和生理生化的影响2个方面研究了生防菌株的抑菌机制。结果表明,两生防菌株发酵液的正丁醇提取物可降低病原菌菌体的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、多酚氧化酶(PPO)、己糖激酶(HK)、丙酮酸激酶(PK)、乳酸脱氢酶(LDH)、苹果酸脱氢酶(MDH)、琥珀酸脱氢酶(SDH)与辅酶I的活性,使Na^+,K^+-ATP酶、Mg^(2+)-ATP酶和Ca^(2+)-ATP酶的活性急剧下降;两生防菌株可显著提高病原菌菌丝体的电导率和丙二醛(MDA)含量,降低病原菌蛋白质含量。说明两生防菌株可通过影响病原菌的代谢系统和生理过程来发挥其抑菌作用。

Trichoderma aureoviride strain YGF9 and Fusarium equiseti strain LX6F2 were two biocontrol strains which were respectively isolated from poplar tissues and soils.In order to explore the mechanisms of these strains in preventing disease,their biocontrol efficacies to poplar canker caused by Botryosphaeria dothidea,their disturbance to the pathogen＇s metabolic pathways and influence on the pathogen＇s physiological function were investigated.It showed that the N-butanol extract from the fermented liquids of strains YGF9 and LX6F2 could reduce the activities of SOD,CAT,POD,PPO,HK,PK,LDH,MDH,SDH and coenzymeⅠ,and caused the enzyme activities of Na^＋,K^＋-ATP,Mg^2＋-ATP and Ca^2＋-ATP enzyme to decline sharply.The two strains were able to increase the electrical conductivity and MDA content of the pathogen significantly,and reduce the protein content of the pathogen.In addition,it was found that the two biocontrol strains could destroy the metabolic pathways and affect the physiological function of the pathogen,which might be the reasons why the strains YGF9 and LX6F2 could prevent poplar canker.