甘薯种质基腐病抗性鉴定和分析

Identification and Analysis of Resistance to Foot Rot of Sweetpotato Germplasm

摘要:

为探索甘薯基腐病田间抗性鉴定方法和筛选抗病种质，该研究对经过1~3 a试验筛选的81份甘薯(Ipomoea batatas)抗性或其他性状优良的种质进行田间抗病性鉴定，并分析甘薯不同生育时期的病情变化，以及不同抗性等级对鲜薯产量损失率的影响。结果表明，在81份种质中，表现为高抗和抗的种质分别有24和11份。生长期从90到120 d的病情变化明显，尤其是感病种质的4级病级比例迅速提高。鲜薯产量与病情指数呈极显著的负相关(r=-0.978 1^**)，每下降1个抗性等级，鲜薯平均产量损失率将增加19.35%。生长期120 d时发病率与病情指数之间呈极显著正相关(r=0.992 5^**)，除病情指数外，发病率也可作为甘薯基腐病抗性鉴定指标。

Abstract:

In order to explore the field resistance identification method of sweet potato (Ipomoea batatas) foot rot and to screen resistant germplasm, a total of 81 germplasms with resistance or other traits were identified after 1-3 years experiment, and the disease changes in different growth stages of sweet potato and the effects of different resistance grades on the yield loss rate of fresh sweet potato were analyzed. The results showed that among the 81 germplasms, 24 and 11 were highly resistant and resistant, respectively. From 90 to 120 d of growth stage, the disease changed obviously, especially the proportion of grade 4 disease of the susceptible species increased rapidly. There was a significant negative correlation between fresh potato yield and disease index (r= -0.978 1^**), and the average yield loss rate of fresh potato increased by 19.35% for each resistance grade decrease. At 120 d of growth stage, there was a significant positive correlation between incidence and disease index (r= 0.992 5^**). Therefore, in addition to disease index, incidence could also be used as an index to identify resistance to foot rot of sweet potato.