引致桂花叶斑病的葡萄座腔菌生物学特性及药剂毒力测定

Biological Characteristics of the Leaf Spot Lesions of Osmanthus fragrans and Its Resticide Sensitivity

以桂花为试材,利用组织分离法分离桂花叶斑病菌,并对其进行形态特征鉴定和rDNA-ITS序列分析,研究了该病原菌的生物学特性及其对9种杀菌剂的敏感性。结果表明：该病原菌为葡萄座腔菌;光照对病原菌的生长无明显影响;菌丝生长的最适温度20～30℃;最适pH6～9;最适碳源为葡萄糖、蔗糖和麦芽糖;最适氮源为硝酸钾和天冬酰胺。9种杀菌剂对桂花叶斑病菌的生长均表现出抑制作用,其中苯醚甲环唑、戊唑醇和氟硅唑的毒力最强,EC50分别为0.6839、0.8754、1.2236μg/mL;百菌清毒力最弱,EC50为57.0778μg/mL。

Taking sweet osmanthus as material,tissue isolation method was conducted to isolate the pathogen.The pathogen was identified by the morphological characters and its internal transcribed spacer（ITS）sequence of rDNA.Meantime the biological characteristics of the pathogen and its sensitivity to nine fungicides were studied.The results showed that the pathogen was Botryosphaeria dothidea.The influence of illumination on the growth of hyphae was not significant.The optimal temperature for the growth of hyphae was 20-30℃and the optimal pH value was 6-9.The best carbon sources were glucose,sucrose and maltose.The best nitrogen sources were KNO3 and asparagine.All of nine fungicides could inhibit the growth of hyphae,the inhibitory activities of difenoconazole,tebuconazole and flusilazole were the highest with EC50 of 0.6839,0.8754,1.2236μg/mL,and the inhibitory activities of chlorothalonil was the lowest with EC50 of 57.0778μg/mL.