辣椒疫病生防真菌F_1的生物学特性及生防作用

Study on some characteristics and the bio-control effect of fungi numbered F_1

采用形态鉴定，碳、氮源利用及耐药性试验对生防真菌F1的分类地位和生物学特性进行了研究，并利用盆栽、温室生物实验及离体实验研究了F1对辣椒疫病的防效及防病机理。结果表明：（1）F1为曲霉属[Aspergillus Micheli ex Fr]舒展曲霉（A.effusus Tiraboschi）；（2）F1对辣椒疫病防效明显，在盆栽线椒和温室甜椒生防实验中的相对防效分别为83．3％和94．1％；（3）F1对辣椒疫霉菌丝生长相对抑菌率为57％～100％，对游动孢子萌发相对抑制率为78．9％；（4）F1能在辣椒根内定殖，单独接种F1与F1＋P1混合接种后8，24和42d时,F1的定殖密度分别为4×10^3／g，5×10^3／g,3×10^3／g和13×10^3／g，3．5×10^3／g，2．3×10^3／g；（5）接种F1对辣椒叶片苯丙氨酸解氨酶（PAL）与多酚氧化酶（PPO）活性有影响。接种24d时，单独接种下，处理辣椒叶片PAL与PPO酶活分别较不接菌对照降低47．9oA与26．3％，而F1＋P3混合接种处理辣椒叶片PAL活性较对照提高86．7％，PPO活性较对照降低29．9％。

The classification and some characteristics of fungi numbered F1 were studied by morphological identification ,the experiment of utilizing different carbon and nitrogen source and the tolerance tO different antibiotics;the capsicum was planted in pot and greenhouse and inoculated with F1 to study the biocontrol effect and mechanism. Results showed that： （1） F1 fell into the category of aspergillus Micheli ex Fr,and was initially identified as A. effusus Tiraboschi; （2） F1 had good control effect on capsicum＇s disease caused by Phytophthora capsici in pot planted and greenhouse planted,and the relative control effects were 83.3% and 94. 1% respectively, （3） the fermentation fluid of F1 could obviously inhibit the mycelium growth and the germination of zoospores of Phytophthora capsici. And the percentages of inhibition were 57%-100% and 78.8% respectively; （4） F1 could colonize in the capsicum＇s root. 8 days,24 days and 42 days after inoculation,the colonization densities of the treatment of F1 individual inoculation and the treatment of F1＋P3 were 4,5,3 and 13,3.5,2.3 （ × 10^3/g）respectively ; （5） The PAL and PPO activities in the leaves of the capsicum were affected by F1 inoculation. In the treatment of F1 inoculation,the PAL and PPO activities in the leaves of the capsicum declined by 47.9% and 26.3%. In the treatment of F1＋P3,the PAL activities increased by 86.7% ,but the PPO activities declined by 29.9 %.