烟草品种抗青枯病鉴定中相关因素分析

ANALYSIS OF CORRELATED FACTORS ON THE IDENTIFICATION OF TOBACCO BACTERIAL WILT RESISTANCE

用烟草青枯病t1菌株对G3、红花大金元等品种分别作不同接种方法、不同菌量、不同年份和不同生育期接种试验以及与黄瓜花叶病(CMV)交叉接种试验.结果表明,参试品种在烟株旺长初期,用切根灌菌液接种与病区自然鉴定之间对青枯病抗性呈极显著正相关(r=0.9855),接种体浓度以108cfu/ml为宜.不同抗感品种在不同年份重复鉴定中表现出不同程度的抗性波动,用相对抗病指数评价品种抗性,可减少误差.参试18个品种不同生育期与t1菌株的互作反应,分为苗感成株期抗病型和全期感病型两类.烟株生长初期交叉接种黄瓜花叶病毒(CMV)与青枯病菌明显减轻青枯病病情,但干扰了抗病性鉴定.查清了上述影响因素后,可以组装一套规范化的烟草品种抗青枯病筛选鉴定模式.

The resistances of tobacco varieties to Ralstonia solanacearum isolate t1 were evaluated by using different approaches,concentrations,and cross inoculation at different growth stages in different years. Extremely high positive correlation( r = 0.9855) was observed between pouring fermen-tation(108cfu/ml the best) into injured root and growing in disease field. The resistance fluctuated among different years. By using relative resistance index to evaluate the resistance, the error could be decreased. According to the interaction between growth period and t1 isolate, 18 varieties could be divided into 2 groups. One was susceptible at seedling stage but resistant at adult and the other susceptible during the whole growth period. Cross infecting CMV and bacterial could obviously decrease tobacco wilt disease at early growth stage but this disturbed the resistance identification. A model for resistance identification was built.