枣果贮藏期红粉病菌鉴定及环境因子对其分生孢子萌发的影响

在山西省临县、太谷县发现枣贮藏期红粉病,发病初期果实表面出现圆形或椭圆形的白色絮状霉点,后期形成较厚粉状霉层。从病样中分离获得2株代表性菌株,通过病原菌分离培养、致病性测定、形态学特征及ITS序列特征分析,确定引起枣贮藏期红粉病的致病菌为粉红单端孢(Trichothecium roseum)。适合该病菌分生孢子萌发的温度为20℃~25℃,相对湿度为大于75%,pH=4~10,致死温度为48℃、处理10 min。适宜芽管生长的温度为20℃~25℃,相对湿度为大于75%,最适pH=6。本研究结果可为枣贮藏期红粉病的诊断和防治措施的制定提供理论依据。

Identification of the pathogen causing pink mold rot in stored jujube fruit and effects of environmental factors on conidial germination

The pink mold rot on traditional fruit tree Ziziphus jujube was observed in plantation of Shanxi pro-vince. At the beginning, pink mold rot appeared as white mold on the fruit surface. As the disease progressed, it changed to thick and larger powdery mildew lesion with variation in the size. The appearances were punctiform, mottling, patching, ellipse and so on. The morphological characteristics, pathogenicity test and molecular identification method were used to confirm the pathogen of pink mold rot. Two representative strains of Trichothecium roseum were identified in this study based on morphological and physiological tests in addition to the ITS sequence comparison. The conidia of T. roseum germinated with optimal conditions at 20℃-25℃, pH 4-10, and over 75% relative humidity. The lethal temperature for conidia of T. roseum was 48℃ for 10 minutes. The germ tube of T. roseum grew with an optimal condition at 20℃-25℃, pH 6, more than 75% relative humidity. The results of this research provide the theoretical basis for disease diagnosis and control measures.