摘要： 由大蒜叶枯病菌引起的大蒜叶枯病是徐淮地区大蒜生产中的重要病害之一，拟通过对该病原菌生物学特性研究和室内高效低毒化学药剂筛选，为大蒜安全生长提供理论依据。采用十字交叉法研究该病原菌生物学特性，结果表明：该病原菌生长的最适碳源为D-木糖，氮源为硝酸钾，pH值为5~12时均生长较好，菌落直径7.55~9.15 cm，菌丝对光暗条件不敏感，但在黑暗环境下菌落直径最大，为7.30 cm，菌丝致死温度为57℃、5 min，最适温度为22℃，菌落直径为7.78 cm。采用菌丝生长速率法测定了5种杀菌剂对该病原菌的室内毒力。结果显示，5种杀菌剂对大蒜叶枯病菌的毒力差异显著，其中96%苯醚甲环唑EC₅₀最低，为0.017 4；其次是98%吡唑醚菌酯，其EC₅₀为0.892 7；其他3种药剂EC₅₀较高，分别是98.4%百菌清EC₅₀为9.959 0；98.5%醚菌酯EC₅₀为18.080 4；98%多菌灵EC₅₀为45.387 7。

关键词: 大蒜叶枯病菌, 生物学特性, 毒力测定

Abstract: Garlic tip blight which caused by Pleospora herbarum is one of the important diseases in garlic production in Xuzhou area.In this study,the biological characteristics of Pleospora herbarum and the selection of high efficiency and low toxicity fungicides was studied to provide theoretical basis for safe production of garlic. The biological characteristics of this pathogen was analysed by cross method. The results showed that the best carbon source in this study was D-fructose,and the best nitrogen source in this study was potassium nitrite,and the suitable pH was from 5-12,with colony diameter from 7.55-9.15 cm. Mycelium was not sensitive to the light,but in darkness the colony diameter which was 7.30 cm was the longest;The lethal temperature of the pathogen was 57℃,5 min. The most suitable temperature was 22℃,and the colony diameter was 7.78 cm. The toxicity of five fungicides to Pleospora herbarum was tested by mycelia growth inhibition. The result showed that the toxicity to this pathogen of these 5 fungicides was significantly different.Among the 5 fungicides tested,the highest inhibition effect to mycelia growth of Pleospora herbarum was observed with 96% difenoconazole,the value of EC₅₀ was 0.017 4;The better fungicides followed by was 98% pyraclostrobin,the value of EC₅₀ was 0.892 7;98.4% chlorothalonil,98.5% kresoxim-methyl and 98% carbendazol had the lowest effect and the values of EC₅₀ were 9.959 0,18.080 4 and 45.387 7,respectively.

Key words: Pleospora herbarum, Biological characteristics, Toxicity test

中图分类号: 

• S436.33