蜘蛛兰的一种新病害——褐斑病的鉴定记述

从观赏花卉蜘蛛兰(Hymenocallis littoralis)上发现一种叶部病害,通过组织分离、纯化获得2种真菌,按照柯赫氏证病律方法确定其均为该病害的病原菌.根据2种真菌的菌落、分生孢子盘和分生孢子等的形态特征鉴定,它们分别为刺盘孢(Colletotrichum sp.)和拟盘多毛孢(Pestalotiopsis sp.).病菌主要侵染植株的叶片,接种试验表明它们可以单独侵染,也可以复合侵染,引起相似的症状,但2种病菌混合接种后发病更快更重.室内接种叶片和田间自然发病叶片上的症状相同,初为水渍状灰褐色的小点,扩展后形成典型的圆形或椭圆形病斑,中央灰色至灰褐色,边缘紫褐色至红色,周围有明显的黄色晕圈带,后期病斑互相连接,导致叶片大面积或全部成灼烧状枯死并萎垂.该文描述了2种病原菌的菌落、分生孢子盘和分生孢子等主要结构的形态特征,但它们的种名还需要进一步研究确定.

Record and Description of a New Disease on Spider Lily (Hymenocallis littoralis): Brown Leaf Blotch

A new disease was found on spider lily (Hymenocallis littoralis (Jacq.) Salisb. ) plants and it was diagnosed as a brown leaf blotch caused by the infections of Colletotrichum sp. and Pestalotiopsis sp. The typical symptoms of the disease were characterized the initial small circular purple spots on leaves, which developed to oval spots and may join together to form large irregular spots. The spots are brown at the center, deep purple at the border and surrounded by a yellow halo of newly-infected tissue. Isolation and inocu]ation showed that two fungal species were the pathogens causing the disease: Colletotrichum sp. and Pestalotiopsis sp. They induced blotch symptoms on leaves after separate and combined inoculations. The disease was widely distributed in Chongqing and other provinces of Southwest China and significant damages were frequently observed in some gardens or spider lily plantations. The disease symptoms and the morphology of pathogens are described and further works on epidemiology and control of the disease are discussed in the paper.