烟草抗青枯病突变体的室内接种鉴定

Indoor Inoculation Identification of Tobacco Mutants Resistant to Bacterial Wilt

为探寻更加快速准确的烟草青枯病抗病性室内鉴定方法,为烟草抗青枯病材料的抗病性鉴定、筛选及后续研究提供参考,本研究选用14个经EMS诱变获得的烟草抗青枯病突变体及‘红花大金元’、‘翠碧一号’、‘岩烟97’三个对照品种为研究对象,采用伤根浸泡法接种烟草幼苗,对4种浓度梯度(1×10~6 cfu/m L, 1×10~7cfu/mL, 1×10~8cfu/mL和1×10~9 cfu/mL)的青枯菌菌悬液接种的烟草幼苗的发病情况进行了连续的调查,确定了最适的接种浓度和病情调查时间,并与自然病圃病情调查结果进行相关性分析,系统评价了室内伤根浸泡法在快速评价烟草青枯病抗性中的可行性。结果显示,以浓度为1×10~8 cfu/mL的青枯菌菌悬液进行浸染、接种第12天调查获得的发病情况为主要评价指标,14个供试材料的室内抗病率与田间自然病圃抗病率非常接近,呈极显著正相关,相关系数为0.964。由此可见,室内可控条件下的伤根浸泡法能够真实地反映材料的抗性水平,具有快速、经济、可靠的优点,可以为烟草青枯病抗性鉴定提供科学依据。

In order to search for a more rapid and accurate laboratory identification method for tobacco bacterial wilt resistance, and to provide a reference for the identification, screening and follow-up study of tobacco resistance to bacterial wilt in China, we evaluated the injured root soaking method performed in chamber using 14 mutants generated via treatment of EMS and three control cultivars ＇Honghuadajinyuan＇, ‘Cuibi No. 1＇, and ‘Yanyan 97＇ in this study. Four gradient concentrations of Rastonia solanacearum （1×10^6 cfu/mL, 1×10^7 cfu/mL, 1×10^8 cfu/mL, and 1×10^9 cfu/mL） were applied to inoculate tobacco seedlings by injured root soaking method. Then their incidence was continuously investigated to confirm the most appropriate inoculum concentration and the best time for symptom investigation. Also, the correlation analysis was made with the survey results of natural diseases, and the feasibility of indoor root soaking in rapid evaluation of resistance to tobacco bacterial wilt was systematically evaluated. Therefore we confirmed 1×10^8 cfu/mL as the optimal inoculated concentration and 12 d post inoculation as the optimal time of disease resistance investigation by using different concentrations of Ralstonia solanacearurn suspension to treat tobacco seedlings continuously, in which condition the disease incidences of all the 14 tobacco materials were very close to those in infected field with the correlation coefficient 0.964 （R value）. It could be seen that the root soaking method under controlled indoor conditions could truly reflect the resistance level of the material, which had the advantages of fast, economic and reliable, and might provide scientific basis for the identification of tobacco bacterial wilt resistance.