不同致病力稻曲病菌的生物学特性研究

Biological Characterization of Ustilaginoidea virens with Different Pathogenicity

为了深入研究稻曲病菌生物学特性，为防治稻曲病提供科学依据。本研究从不同致病力稻曲病菌中，挑选了3个致病力强、3个致病力弱的菌株，从不同温度、pH、碳源、氮源对不同致病力的稻曲病菌进行研究。结果表明，稻曲菌菌丝生长的最适温度均为28℃，在7d内致病力弱的菌株生长速率较快，菌丝生长的最适pH为6—7。致病力弱的菌株的最适氮源为牛肉浸膏，致病力强的菌株的最适氮源为蛋白胨，KN03不为稻曲病菌提供氮源，尿素抑制稻曲病菌的生长。在氮源充足的条件下，稻曲病菌可以利用多种碳源，乳糖不能为稻曲病菌提供碳源，致病力弱的菌株的最适碳源为蔗糖，致病力强的菌株的最适碳源为葡萄糖。

In order to study the biological characterization of the Ustilaginoidea virens and provide the scientific basis for preventing and controlling the false smut of rice, 3 weak pathogenicity and strong pathogenicity strains were selected from previous research in lab, the tem- perature, pH, carbon and nitrogen source for the growth of the different isolates were studied in this paper. The results showed that the opti- mum temperature for hyphae growth was 28 ℃, and the colony of isolates with weak pathogenicity grew faster than that of isolates of strong pathogenicity in 7 d post inoculation, the optimum pH for hyphae growth was 6.0 -7.0. The peptone was the best nitrogen source for the isolates with weak pathogenicity, and the beef extract was the best nitrogen source for the isolates with strong pathogenicity. KNO3 could not provide nitrogen source for the U. virens, and the carbamide restrained the growth of the U. v/tens. Under full nitrogen source, the U. virens could use most carbon source, but lactose not be used, the sucrose was the best carbon source of the weak pathogenicity strains, and the glucose was the best carbon source of the strong pathogenicity strains.