杨梅叶提取物对6种常见植物病原菌的抑制活性

采用生长速率法对杨梅Myrica rubra叶丙酮提取物和杨梅素进行了系统的抑菌作用测定。杨梅叶丙酮提取物对水稻纹枯病菌Rhizoctonia solani,油菜菌核病菌Sclerotinia sclerotiorum,番茄灰霉病菌Botrytis cinerea,小麦赤霉病菌Fusaium graminearum,苹果腐烂病菌Valsa mali,棉花枯萎病菌Fusarium oxysporum f.vasinfectum等6种植物病原菌均有较强的抑制活性,其抑制中质量浓度EC50分别为：23.08,19.85,25.86,22.07,23.18和22.86 g·L^-1;杨梅素对以上6种菌的EC50分别是：0.32,0.33,1.09,0.69,0.34和2.09 g·L^-1,其中对水稻纹枯病菌、油菜菌核病菌和苹果腐烂病菌的抑制活性较高。采用番茄果实组织法,测得杨梅叶丙酮提物和杨梅素水乳剂对番茄灰霉病的治疗作用和保护作用。测定结果表明,杨梅叶丙酮提取物10倍稀释液（40 g·L^-1）有较强的效果。

Antifungal activity of extracts from leaves of Myrica rubra

The objective is to test the antifungal activity of extracts from Myrica rubra leaves and myricetin. Based on a preliminary test for inhibition of acetone extracts from leaves of Myrica rubra, the fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Botrytis cinerea, Fusarium graminerum, Valsa mali and Fusarium oxysporum f. vasinfectum were selected and their mycelium growth rate were tested in five concentrations （among 5, 10, 20, 30, 40, 50, and 60 g·L^-1）. Antifungal activity was also tested with pure myricetin acetone solution in five concentrations （among 0.30, 0.40, 0.50, 0.60, 0.70, and 0.80 g·L^-1）. Results showed that when restraining effect were 50%, concentrations of extracts from leaves of M. rubra were （in g·L^-1） R. solani（23.08）, S. sclerotiorum（19.85）, B. cinema （25.86）, E graminerum（22.07）, V. ma/i（23.18）, and F. oxysporum f. vasinfectum （22.86）. Meanwhile, when inhibition was 50%, concentrations with pure myricetin acetone solution for the same fungi were 0.32, 0.33, 1.09, 0.69, 0.34 and 2.09 g·L^-1 respectively. A stronger effect of 10 times the diluent from leaves of M. rubra showed a therapeutic action 42.3% and a protective function 45.6% on tomato. Ch. 3 tab. 11 ref.]