甘肃省白芷斑枯病菌及其生物学特性

Pathogen identification and biological characteristics of spot blight in Angelica dahuricain Gansu Province

【目的】旨在明确甘肃省白芷斑枯病病原及其生物学特性.【方法】试验采用植物病理学、形态学和常规培养的方法对甘肃省白芷斑枯病菌进行了研究.【结果】病原分生孢子器扁球形,高66.2～137.3μm(平均104μm);直径74.3～109.1μm(平均92μm);分生孢子无色,粗线状,弯曲成弓状,1～3个隔膜,大小11.8～25.9μm×1.4～2.1(平均18.0×1.9)μm.依据形态将甘肃省白芷斑枯病菌确定为(Septoria dearnessii Ellis et Ev.).该菌菌丝生长,分生孢子萌发和产孢的温度范围分别为5～35、10～30、5～35℃,最适温度分别为20～25℃、15℃、20～25℃;光照条件对菌丝生长、产孢和孢子萌发无明显影响;菌丝生长、孢子萌发和产孢的pH范围分别为4.0～10.0、4.5～9.2和5.0～10.0,最适pH分别为7.0、7.0和7.5;此菌在相对湿度75%以上均可萌发,以水中萌发最好,72h可达48.3%;白芷叶和根渍液对孢子萌发有较强的促进作用,72h可达73.3%.【结论】白芷壳针孢菌丝生长和孢子萌发的适宜温度偏低,因此在甘肃省该病害在气温偏低及持续阴雨结露条件下发生较重.

【Objective】In order to identify and test the biological characteristics of pathogen of spot blight in Angelica dahurica in Gansu Province.【Method】Morphological and regular cultural methods were combined to identify the pathogen and test the biological characteristics of the pathogen.【Result】The pycnidia of pathogen was spherical or sub-spherical,74.3to 109.1μm(mean=104μm)in diameter,66.2to 137.3μm(mean=92μm)in height,conidia hyaline,arciform,1~3septate,11.8~25.9×1.4~2.1(mean=18.0×1.9)μm.Based on morphological comparison with the recorded data,the pathogen was Septoria dearnessii Ellis et Ev..The adaptation temperature ranges for hypha growth,spore germination and production were 5to 35 ℃,10 to 30 ℃ and 5to 35 ℃ respectively.The optimum temperature were correspondingly 20 to 25℃,15℃and 20 to 25℃.Hypha growth,spore production and germination were not affected by illumination condition.The pH range of the hypha growth,spore germination and production were 4.0to 10.0,4.51 to 9.19 and 5.0to 10.0respectively with the optimum of 7.0,7.0and 7.5.The spore could germinate under 75% or higher relative humidity but best in water(48.3% after 72hours).The extracts from leaf and root could promote the spore germination.【Conclusion】The low temperature adaption of mycelium growth and spore germination of the pathogen indicated that the disease would be serious under low temperature,dewing and continuous rainy weather in Gansu Province.