臺灣發生由Erwinia herbicola pv. gypsophilae引起之滿天星細菌性腫瘤病

Abstract

在臺灣埔里地區苗圃培育之滿天星抒插苗上，於1991年首先發現其莖基部有產生腫瘤之病害，隨後在其他地區之杆插苗及田間栽植之滿天星植株亦發生相同的病害。被害植株葉片呈現黃化並向內彎曲，最後整個植株萎凋枯死，形成之腫瘤最初為淡黃色或淡褐色，後轉為深褐色，質地軟且易碎，抒插苗上之腫瘤約6 mm，而田間罹病植株之腫瘤可達3cm。顯微鏡觀察，病莖腫瘤內部有許多細菌分佈其中。由腫瘤組織經常分離到一種革蘭氏陰陸，桿狀，形成黃色菌落之細菌。該細菌經生理生化特性測定，Biolog系統測定及細胞脂肪酸組成分析結果，均鑑定為Erwinia herbicola，其特性與Erwinia herbicola Eh112y菌株之特性相同。分離的細菌經接種於滿天星植株莖基部，可引起腫瘤病微，因此確定該病害是由Erwinia herbicola pv. gypsophilae 引起之滿天星細菌性腫瘤病(bacterial gall disease)。測試市售10種殺菌劑包括銅劑、抗生素及混合藥劑在一般使用之濃度對滿天星腫瘤病菌生長之抑制效果，顯示大多數的菌株對氫氧化銅及鹼性氯氧化銅具抗性，而大多數的菌株則可被抗生素如鏈黴素、嘉賜黴素、四環黴素及銅劑與鋅錳乃浦的混合劑等藥劑抑制。. Serious crown and root galls on nursery rooted cuttings of Gypsophyla paniculata were first observed in Puli, Taiwan in 1991. Subsequently, the gall disease was also found in other areas. The infected plants showed leaf yellowing, and eventually wilted and died. The galls were soft, friable, about 6 mm -3 cm in size, and initially light yellow or light brown but gradually turned to dark brown. The microscopic observations revealed that the galled tissues were filled with numerous bacteria. A yellow, gram-negative rod-shaped bacterium was consistently isolated from the galled tissues. Strains of the isolated bacterium induced gall symptoms on inoculated plants of G. paniculata. The bacterium was identified as Erwinia herbicola pv. gypsophilae based on the physiological characteristics, the Biolog GN MicroPlate system, the MIDI system for cellular fatty acid anslysis, and the pathogenicity test. The commercial agrochemicals including copper bactericides, antibiotics and mixed formulations at generally used concentrations were tested for their inhibitory to the growth of E. herbicola pv. gypsophilae. Most strains of the bacterium were resistant to copper hydroxide and copper oxychioride, but were sensitive to streptomycin, kasugamycin, tetracycline and copper oxychloride-mancozeb combination.