不同接种方式下番茄溃疡病病原菌的致病效果比较

番茄溃疡病(Bacterial canker of tomato)是目前国内外番茄生产上最严重的细菌病害之一。为建立准确有效的人工接种鉴定体系，本研究采用5种不同的人工接种方式(剪顶法、喷雾法、复叶柄注射法、茎顶端注射法和茎基部注射法)对番茄植株进行接种，比较和分析了接种后各群体植株起始发病时间、平均发病率、病情指数和平均死株率等指标。结果表明:剪顶法和茎部注射法接种病原菌致病效果最好，发病率达到100.0%，病情指数>75.0，但是剪顶法接种后植株死亡率很高，接种40 d时死亡率高达96.7%，不利于后续的遗传分析及留种；进一步分析发现茎基部注射接种时病原菌在植株体内传播速度更快；用5份抗感性不同的番茄材料及2个遗传分离群体共计742株番茄进行茎基部注射接种，结果表明该法接种后可以准确区分番茄材料的抗感性。综上所述，本研究结果表明茎基部注射法接种适用于番茄材料抗溃疡病评价及遗传分析，为抗溃疡病番茄材料的筛选及抗性品种的培育提供了有力支撑。

Comparison of the pathogenic effect of bacterial canker pathogen under different inoculation methods in tomato

Bacterial canker, a systematic disease caused by Clavibacter michiganensis (Cm), is one of the most serious bacterial diseases in tomato worldwide. To establish an accurate and effective artificial inoculation and phenotype identification system for the resistance breeding, five artificial inoculation methods, including top-pruning, spraying, complex leafstalk injection, stem top injection and stem base injection, were adopted to inoculate plants of five different tomato lines with the Cm pathogen. The time of disease emergency, average incidence, disease index and average death rate were recorded and compared. The results showed that: Top-pruning and stem injection were the most effective methods to induce disease with 100. 0% incidence and greater than 75. 0 disease index. However, top-pruning caused the 96. 7% death rate of infected plants at 40 days post inoculation, which was not suitable for subsequent genetic analysis and obtaining seeds. Thus, the pathogenic effects of the pathogen introduced by top and base stem injection methods were further compared. The result showed that the pathogen spread faster in plants by stem base injection than by stem top injection. To verify this result, a total of 742 plants from three susceptible tomato lines, two resistant lines and two segregated populations were subjected stem base injection of the pathogen. The data showed that stem base inoculation accurately distinguished the resistance and susceptible phenotypes based on the inducing the distinct average incidence and disease index. In conclusion, this study indicated that the stem base injection method is suitable for evaluation of resistance to bacterial canker and genetic analysis, which provides a tool for screening sources resistant to bacterial canker and resistant cultivar breeding.