Isolation and Identification of Black Spot Pathogen in Psidium guajava

[Objective]The aim was to isolate and identify the pathogen causing black spot disease in guava（Psidium guajava）,so as to determine its taxonomic status.[Method]The fungus was identified by determining its pathogenicity,observing its morphology characteristics and analyzing its ITS sequence.[Result]The pathogen causing black spot disease in guava was a strain of Guignardia mangiferae.[Conclusion]This study will provide theoretical basis for curing black spot disease of guava.

稻曲病的流行规律和防治研究

稻曲病 Ustllaginoidae virens(Cooke)Tak,又名青粉病、谷球病、黑球病,是危害水稻穗粒的一种真菌性病害。李时珍在《本草纲目》中所记述的“粳谷稻、谷穗煤黑者”是有关此病的最早记载。1987年 Cooke 根据在印度获得的标本,首次对该病作了描述。据浙江、江苏、广东、福建、湖南、天津、沈阳等省市报导,此病从1979年开始回升,1981、1982,1984年病害大发生,它不仅影响水稻产量,而且严重污染稻谷,影响人畜健康。据浙江省农业厅统计,稻曲病轻发年份,1985年早、晚稻发病面积231.40万亩,全面防治后仍然损失稻谷759.47万斤。