红橘褐斑病病原鉴定

 自2007 年起重庆万州的红橘(Citrus reticulata Blanco, CV. Hongjv)上爆发一种未曾见过的病害,损失严重,因病斑褐色,故被称之为褐斑病。褐斑病贯穿柑橘整个生长季节,主要为害叶片和果实,严重时也为害新梢,引起大量落叶和落果,甚至枝梢枯死。为明确其病原,本研究从病区多个果园采集发病的叶片、果实和枝梢,检查和分离培养发现病组织中广泛存在链格孢菌(Alternaria)和炭疽菌(Colletotrichum)。致病性试验证明只有链格孢菌才能引起类似褐斑症状,而炭疽菌和空白对照都不产生任何症状。通过比较研究这些链格孢菌菌株的形态学,培养性状和多聚半乳糖醛酸酶(endoPG)基因的部分序列,可以断定红橘褐斑病的病原为交链格孢菌A. alternate (Fr. ) Keissler]。病原性质的确定将为红橘褐斑病发生规律的研究和控制奠定基础。

Identification of the pathogenic fungus causing brown spot on tangerine( Citrus reticulata CV.Hongjv

An unknown disease has been breaking out and causing a great loss on Hongjv(Citrus reticulata Blanco,CV.Hongjv) since 2007 in Wanzhou,Zhongqing,China.The disease was characterized as the brown spot on affected tissues and named brown spot disease temporarily.The disease occurs around a growing season and the severe affected leaves and fruits drop quickly.To determine the causing agent,the infected leaves,fruits and shoots were collected from different orchards.Typical conidiospores and cultures of Alternari...