烟草赤星病人工接种鉴定新方法研究

A New Artificial Inoculation Identification Method for Tobacco Brown Spot

烟草赤星病发生于烟草生长中后期,是烟草生产上威胁最大的叶部病害之一。人工接种是确定赤星病菌致病性强弱及优势菌群,并进行烟草种质资源与品种抗病性鉴定筛选工作的关键。为了探索出室内人工接种赤星病菌的高效方法,本研究提供了一种离体叶片人工接种鉴定新方法,即孢子悬浮液伤口注射法,同时比较了不同接种方法的接种效果以及接种浓度、病原菌菌龄、叶片部位对孢子悬浮液伤口注射法接种效果的影响。结果表明:孢子悬浮液伤口注射法具有操作简便、接种率高、发病时效期短、发病程度适中、结果准确可靠的优点,接种的最佳条件是烟草赤星病菌菌龄为10 d,孢子悬浮液浓度为1×10^(6)个/mL,叶片部位为下二棚,接种量为10μL。通过该新接种方法,可快速准确地鉴定烟草赤星病或作物叶部病原真菌。

Tobacco brown spot occurs in the middle and late stages of tobacco growth period and is one of the most threatening leaf diseases in tobacco production.Artificial inoculation is the key to determine the pathogenicity and domi-nant pathogen community of Alternaria alternata,and to identify and screen the disease resistance of tobacco germplasm resources and varieties.In order to explore an efficient method for indoor artificial inoculation of A.alternata,this study provided a new method for identification of artificial inoculation of leaves in vitro,namely spore suspension wound injection method,and compared the inoculation effect of different inoculation methods,as well as the influence of inocu-lation concentration,pathogen age and leaf location on the inoculation of spore suspension wound injection method.The results showed that spore suspension wound injection had the advantages of easy operation,high inoculation rate,short onset period,moderate onset degree and accurate and reliable results.The optimal conditions for inoculation of this new method were A.alternata pathogen age of 10 days,a spore suspension concentration of 1×10^(6) cells/mL,leaves in the lower part of the plant,and an inoculation volume of 10μL.The new inoculation method can be used as a rapid and accu-rate inoculation method for the identification of pathogenic fungi of tobacco brown spot or other leaf diseases of crops.