四川省烟草青枯病的病原菌及发病规律研究

烟草青枯病是四川烟草上的重要病害,主要分布在川东南海拔1000 m以下的烤烟区,7~8月为发病盛期,高温多雨病害严重,干旱可抑制病害的发生。对四川各地烟草青枯病的19个分离菌进行了形态、染色、培养性状、生理生化等方面的研究,鉴定出两种生化型,即生化型III、IV。生化型III占73.7%。各生化型的分布不受地理条件限制。致病性测定结果表明各地的分离菌均为生理小种1号。烤烟品种云97、云98、RG11和RG17较抗病,红大、云85、云87较感病。

Studies on the strains and epidemiology of bacterial wilt of tobacco

19 isolates of bacterial wilt of tobacco from Sichuan were comparatively studied.These isolates are similar in their main morphological,cultural,and physiological,biochemical characteristics.The results indicated the isolates should be Pseudomonas solanacearum Smith.The strains respectively belong to biotype III,IV,based on Hayward classification schemes.The inoculation test for pathogen city proved that all of the strains can be grouped in the race 1,described by Buddenhagen.The surveys indicated the bacterial wilt was one of the principal diseases of flue-cured tobacco in Sichuan.The disease is widespread at low elevation(below 1000 m) of southeast of Sichuan,such as Yibin and Luzhou.The disease incidence is high up to 33 % in Yibin areas.High temperature and rainy season cause the disease epidemic in July and August.Tobacco cultivars such as Yun97,Yun98,RC11 and RC17 were found to be middle-resistant to bacterial wilt of tobacco in the fields.