【摘要】 从辽宁省各地分离到 93个玉米纹枯病菌株 ,经菌丝融合测定 ,结合培养性状及酯酶同工酶谱带比较 ,首次明确了辽宁省玉米纹枯病菌的主要菌丝融合群为 Rhizoctonia solani AG1- IA。致病性测定表明 :R.solani AG1- IA是辽宁省玉米纹枯病的主要致病菌 ,其中以丹东 RS- 950 1菌株的致病力最强 ;品种间存在抗性差异 ,沈试 2 8最抗病 ,沈试 2 9最感病。研究发现不同生育期的玉米下位叶鞘对纹枯病菌的抗性存在差异 ,按拔节期 -抽雄期 -吐丝期顺序递减 ,这种趋势在第 7叶位上表现较第 3叶位明显。此外 ,还从碳源、氮源 ,VB1,温度 ,p H值 ,病菌存活力和腐生定殖能力 6方面研究了玉米纹枯病菌的生物学特性更多还原

【Abstract】 Ninty three isolates of Corn Sheath Blight Pathogen from ecologically different regions in Liaoning Province (Shengyang, Dandong, Wafangdian,Changtu and Beining) were identified as Rhizoctonia solani AG1 IA by anastomosis formation with Japanese Standard isolates(AG1 AG6). The comparison of the pathogen esterase isoenzymes further demonstrated the above conclusion. The isolates of AG1 IA from corn sheath blight showed significant pathogenicity to corn and were determined as the virtual pathogen according to Koch’s postulate. The pathogenicity of the 5 tested isolates collected from different regions was varied. Dandong RS 9501 was the most virulent one. Similarly, a significant difference existed among the 11 tested cultivars, of which Shengshi 28 showed highest level of resistance to the disease, while Shenshi 29 were the most susceptible one. The leap sheath (lower) at different growth stages showed different resistance to the disease with a decreasing trend from shooting to tasseling, and silking. This decreasing trend was more conspicuous on the 7th sheath than on the 3th sheath. Moreover, the biological characteristics of this pathogen were investigated in details in the following aspects: nitrogen and carbon requirement,VB1 dependence, temperature range, pH sensitivity, and the survival and saprophic colonizing ability.更多还原