兰花炭疽病病原菌及其生物学特性的研究

The Pathogen of Orchid Anthracnose and Its Bionomics

本文报道了作者多年来对兰花发疽病的研究结果。先后在兰花32个种或品种的病叶中分离到炭疽病菌。根据魏景超《真菌鉴定手册》,兰花炭疽病病菌的学名为 Colletotrichum orchidearum Allesch。该病菌主要侵染叶片,病斑圆形、半圆形或不规则形,黑褐色,发病严重时造成全叶枯死。病菌菌丝生长的适宜温度为20～30℃,最适为25℃;适宜pH值为4～9,最适为6～7。分生孢子萌发的最低温度为15℃左右,适宜温度为20～30℃。用分离到的病菌培养产生的分生孢子制成悬浮液,人工接到兰花叶片上,不论有伤或无伤接种均可引起发病,这说明分离到的病菌对兰花叶片有致病性。

Based on the identification of Fungus Handbook by Wei Jingchao, the fungus, which was isolated from diseased leaves of thirty-two species or varieties of orchids, is Colletotrichum orchidearum Allesch. The pathogen can infect the leaves. The spots on the diseased leaves are round, nearly round and irregular, brown-black. The diseased leaves died down under the serious infection. The ranges of suitable temperture and pH value for the growth of mycelia are 20～30℃ and 4～9, and optima 25℃ and 6～7, respectively. The lowest temperature for the germination of conidia is 15℃ while the suitable temperature is 20～30℃. The disease occurs when we inoculate the leaves with conidium suspension, whether wound or no wound inoculation.