Zhejiang Academy of Agricultural Sciences
National Natural Science Foundation of China (31901585)，Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding( 2021C02064-1)，Zhejiang Species Resources Protection Fee Project (111721301354052231-1-4)
甘薯基腐病是在浙江省东南沿海地区新发生的、由间座壳属病原菌侵染引起的真菌病害。为了筛选抗病种质资源和探索病害田间自然诱导抗性鉴定方法，对126份甘薯种质资源进行了田间抗性鉴定，并分析了甘薯生长后期的病情变化以及种质抗性对鲜薯产量损失率的影响。结果表明，对照品种浙薯255属于高抗，浙薯38属于抗，浙薯13属于高感。在89份品种资源中不存在高抗种质，仅3份种质属于抗，65%以上品种属于高感。在抗病品种浙薯255的34份杂交后代中筛选出13份抗病种质，其中高抗6份，抗2份。甘薯生长后期病情发生显著变化，尤其是中抗、感种质从120 d至135 d时病情指数跃升幅度大。135 d时整体发病植株的4级病级比例达93.8%，绝大多数发病植株最终基部完全腐烂或枯死。甘薯鲜薯产量与抗性水平呈线性相关，抗性好（高抗或抗）的品种鲜薯产量损失率可以控制在15%以下，而感病品种的鲜薯产量损失率会超过65%，甚至绝收。总之，甘薯基腐病抗病品种资源稀少，通过抗病亲本的常规杂交可以获得抗性好的育种材料，发病率和病情指数均可以作为甘薯基腐病田间自然诱导抗性鉴定指标。
Foot rot of sweetpotato caused by Diaporthe destruens is a new disease in the southeast coast of Zhejiang Province. In order to identify resistant germplasm resources and explore the method of resistance identification in natural induced field, 126 sweetpotato germplasm resources were identified, the changes of disease symptom in late growth period of sweetpotato and effects of resistance on yield loss rate of fresh storage root were analyzed. The results showed that the control variety Zheshu255 was high resistant, Zheshu 38 was resistant and Zheshu 13 was high susceptible. Among the 89 varieties, there was no high resistance germplasm, only 3 germplasms were resistant, and over 65% of germplasms were high susceptible. 13 resistant germplasms were identified from 34 hybrid progenies of resistant variety Zheshu255, including 6 high resistant germplasms and 2 resistant germplasms. There were significant changes of disease symptom in the late growth period of sweet potato, especially the disease index of moderate resistant and susceptible germplasm sharply increased from the growth period of 120 d to 135 d. The disease grade of 93.8% of the total susceptible plants was 4 at the growth period of 135 d. Most of the susceptible plants finally rotted or died at the stem. The yield loss rate of sweet potato with good resistance (high resistance or resistance) could be controlled below 15% , while the yield loss rate of susceptible varieties was over 65% , even no harvest. In a word, the resistant germplasm resources of foot rot disease of sweetpotato were scarce, the good resistant breeding materials could be obtained through the routine hybridization of the resistant parents, and the incidence and disease index might be used as the identification index of resistance to foot rot of sweetpotato in natural induced field.