水稻穗腐病病原分离、鉴定及生物学特性

Isolation,Identification and Biological Characters of Pathogens of Rice Spikelet Rot Disease

水稻穗腐病(rice spikelet rot disease,RSRD)是近年上升较快的一种水稻穗部重要病害,影响水稻产量和稻米品质。从稻穗发病谷粒中,共分离到4种真菌,经形态学、生物学及分子生物学鉴定,分别为层出镰刀菌(Fusarium proliferatum)、澳大利亚平脐蠕孢菌(Bipolaris australiensis)、新月弯孢菌(Curvularia lunata)和细交链孢菌(Alternaria tenuis)。4种病原菌均能在温度4℃～40℃、pH 3～12条件下生长,最适的温度范围是25℃～30℃,不同菌最佳产孢的pH值差异较大。4种菌均能在供试的碳、氮源培养基上生长,不同的碳、氮源对各菌的菌丝生长和产孢的影响不同。穗腐病是由多种病原菌引起的水稻后期穗部褐变病害,病原菌具有多样性、复杂性和致病性分化的现象。

In recently years, rice spikelet rot disease （RSRD） is a kind of fast rising main disease in rice panicle, not only causing rice yield loss but also reducing the quality of rice grains. Based on the morphological, biological and molecular characteristics, four fungal pathogens isolated from the infected rice grains were identified as Fusarium proliferatum , Bi polaris australiensis , Curvularia lunata and Alternaria tenuis , respectively. The four pathogens could grow at 4℃~40℃, pH 3-pH 12. The optimal temperature ranged from 25℃ to 30℃, and the best pH value for sporulation of the four pathogens differed. The four isolates could grow on different carbon and nitrogen sources with great difference in mycelial growth and sporulation. The experimental results indicated that RSRD is a kind of rice panicle disease caused by multi-pathogens, and the pathogens showed the characteristics of diversity, complexity and pathogenicity differentiation.