一种苗期鉴定烟草赤星病抗性的新方法

摘要

High-throughput resistance evaluation in vitro is important for the screening and breeding of tobacco varieties resistant to tobacco brown spot disease. In this study, detached leaves at the seedling stage of 15 tobacco germplasm materials with different resistance to tobacco brown spot disease were inoculated with plugs of Alternaria alternata. The lesion area was used to evaluate the disease resistance of the 15 tobacco germplasm materials after inoculation, and the tobacco resistance identified at the seedling stage was compared with that at the adult stage in the field. The results showed that the lesion areas of 15 tobacco varieties were significantly different after inoculation, and the lesion areas of the susceptible varieties was obviously larger than that of the resistant varieties. The resistance identified at the seedling stage and at the adult stage was similar. At the same location with three years’ field experiments, the correlation coefficients between lesion areas and disease indexes were 0.78, 0.74 and 0.66, all at a significant level. In conclusion, this method of inoculation of fungal plugs on detached seedling leaves can be used to effectively evaluate the resistance of tobacco varieties to brown spot disease at early stages, and lesion area can be taken as an index to accurately indicate the resistance of different tobacco varieties to brown spot disease.%烟草赤星病抗性的高通量鉴定是快速筛选和培育烟草抗赤星病品种的前提条件。以15份对赤星病表现不同抗性水平的烟草种质为材料，采用链格孢菌菌饼接种苗期离体叶片，以发病叶片病斑面积作为抗性评价指标，对15份烟草种质的抗性进行评价，并与其田间成株期赤星病抗性进行比较分析。结果表明，采用苗期菌饼接种，供试15份烟草种质的病斑面积差异显著，感病品种病斑平均面积明显大于抗病品种；各品种苗期赤星病鉴定结果与成株期抗性鉴定结果基本一致，且苗期病斑面积大小与3个不同年份、同一地点的成株期平均病级指数间相关性均达到显著水平，分别为0.78、0.74和0.66。表明本研究探讨的苗期离体叶片菌饼鉴定法可以用于烟草赤星病早期鉴定，病斑面积可以作为评价指标准确反映不同烟草品种间赤星病的抗性差异。