Biological characteristics of Allantophomoides carotae

Chinese. 胡萝卜类腊肠茎点霉（Allantophomoides carotae）是作者在国内首次报道的新种。该病原引起胡萝卜斑枯病（新病害），生产损失巨大。本研究旨在探索该病原生物学特性。研究温度、酸碱度、光照、碳源、氮源对该病原菌丝生长、分生孢子产生和萌发的影响。该菌菌丝生长的温度范围是5～35℃，最适温度25℃；分生孢子萌发的温度范围是10～30℃，最适温度25℃；分生孢子的致死温度是45℃ 30 min或50℃ 10 min；菌丝的致死温度是65℃ 30 min。该菌在pH 4～12范围内均能生长、产生分生孢子并萌发，菌丝生长的最适pH 8～10，孢子萌发的最适pH 7～9；该菌不能在以尿素和天门冬酰氨为氮源的培养基上生长，但以麦芽糖、葡萄糖、乳糖、淀粉、甘氨酸、组氨酸和蛋白胨为碳源和氮源时，菌丝生长快、产孢量大；光照处理对该菌菌丝生长、产孢和孢子萌发无显著影响。初步掌握了该病原菌的生物学特性，为防治该病害提供了理论依据。

English. Allantophomoides carotae is the firstly-reported new strain by the author in China. It can cause the Carrot Spotted Withering Disease, thus makes great damage in the course of the production process. The effects of temperature, pH, illumination and the sources of nitrogen and carbon on the growth of hypha, the emergence and germination of conidiospore of Allantophomoides carotae were studied. The most suitable range of temperature is 10-30℃ and the optimum temperature is 25℃ for hypha growth, the lethal temperature is 45℃(within 30 min) or 50℃(within 10 min) for conidiospore and 65℃(within 30 min) for hypha. Within the pH range of 4-12, the hypha could grow and produce conidiospore, and the conidiospore could germinate. The optimum pH is 8-10 for hypha growth and 7-9 for conidiospore germination; The hypha could not grow on the culture medium which nitrogen source comes from urea and asparagines, but it could grow fast and produce more conidiospore on the culture medium which carbon source comes from maltose, glucose and lactose, and nitrogen source come from glycine, histidiane and peptone. The effect of illumination on Allantophomoides carotae was insignificance to the growth hypha and the emergence and germination of conidiospore. The study of this article tentatively made a research of the biological characteristics of this pathogenic bacteria. It provides a theoretical basis for the prevention and control of this disease.