马铃薯抗褐变品种的鉴定与筛选

Identification and Screening of Brown-resistant Varieties in Potatoes

褐变是马铃薯贮藏和加工过程中常见现象,影响其营养、感官和食味品质,降低其商品价值。以24个马铃薯品种为试验材料,通过测定多酚氧化酶(Polyphenol oxidase,PPO)活性、褐变强度、维生素C含量和褐化指数4个相关指标,对不同马铃薯品种抗褐变能力进行综合鉴定和评价。不同马铃薯品种PPO活性、褐变强度、维生素C含量、褐化指数均存在明显差异。选择PPO活性在15 U以内的11个品种为预选褐变材料;选择维生素C含量在8 mg/100 g以上的7个品种为预选褐变材料;选择初始褐变强度小于0.2,变化值在0.5以内的7个品种为预选褐变材料;选择24 h总褐化指数在Ⅱ级以内,且开始发生褐变时间大于1 h的11个品种为预选褐变材料。对4个褐变相关指标进行相关性和聚类分析,将测试的24个马铃薯品种聚为3类。类型Ⅰ为易褐变类型,类型Ⅱ是中间水平类型,类型Ⅲ是抗褐变类型。筛选出6个抗褐变马铃薯品种,即‘东农314’‘东农324’‘东农325’‘东农328’‘延薯13号’和‘中薯5号’。研究可为马铃薯种质资源创新和抗褐变育种提供基础材料。

Browning is a common phenomenon in the storage and processing of potatoes,which can affect their nutritional,sensory and taste qualities,and reduce their commodity value.In this study,24 potato varieties were used as experimental materials to comprehensively evaluate and identify the browning resistance of 24 potato varieties based ontheir polyphenol oxidase(PPO)activity,browning intensity,vitamin C content and browning index.There were obvious differences in PPO activity,browning intensity,vitamin C content and browning index in different potato varieties.Preliminary browning resistant materials were identified,including eleven varieties with PPO activity less than 15 U,seven varieties with vitamin C content more than 8 mg/100 g,seven varieties with initial browning intensity less than 0.2 and change value within 0.5,and 11 varieties with the total browning index in 24 h less than typeⅡand the initial browning time more than 1 h.Four browning-related indexes were used for correlation analysis and cluster analysis,and the 24 potato varieties tested were clustered into three categories.TypeⅠ,ⅡandⅢwere browning prone type,medium type and browning resistant type,respectively.Finally,six browning-resistant potato varieties were identified,i.e.'Dongnong 314','Dongnong 324','Dongnong 325','Dongnong 328','Yanshu 13'and'Zhongshu 5'.This research would provide basic materials for germplasm resource innovation and browning resistant breeding of potatoes.