广西冬种马铃薯不同品种耐寒性比较

探究低温胁迫下不同品种马铃薯苗期叶片生理生化特性,比较广西冬种不同马铃薯品种的耐寒性,为广西冬种马铃薯品种选育提供参考。以费乌瑞它、兴佳2号、丽薯6号3个马铃薯品种为试验材料,4℃低温下进行0、3、6、12、24、48h胁迫,测定叶绿素、相对含水量、可溶性蛋白含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性。结果表明,随低温胁迫时间的延长,3个不同马铃薯品种的相对含水量、叶绿素含量持续下降,在48h时,费乌瑞它显著低于丽薯6号、兴佳2号。3个品种的可溶性蛋白含量、SOD、CAT活性呈先下降后上升变化趋势,而POD活性呈先上升后下降的变化趋势,在低温胁迫48h时,丽薯6号、兴佳2号的可溶性蛋白含量、SOD活性、POD活性均显著高于费乌瑞它。各品种的MDA含量在低温胁迫48h内呈上升变化趋势,在低温胁迫48h时,费乌瑞它MDA含量显著高于其他品种。3个马铃薯品种的抗寒性由强到弱排列为丽薯6号兴佳2号费乌瑞它,与广西主栽品种费乌瑞它相比,丽薯6号和兴佳2号2个新品种具有较强的抗寒性,可在南方冬作区种植与推广应用。

Cold Resistance of Potato Varieties for Winter-planting in Guangxi

Effects of low temperature on the physiology and cold stress resistance of potato plants were studied for breeding and cultivation of winter-planting varieties in Guangxi.The physiological and biochemical characteristics of the leaves on 3 selected cultivars in response to low-temperature stress during seedling stage were monitored.Favorita, Xingjia No.2, and Lishu No.6 were selected for the study, and the contents of chlorophyll, moisture, soluble protein, and malondialdehyde (MDA), as well as the activities of superoxidedismutase (SOD), catalase (CAT), and peroxidase (POD) in the 5th leaf on a plant were determined after the plant was grown at 4℃ for 0, 3, 6, 12, 24 or 48 h.The results showed that, the leaf relative water and chlorophyll contents of the 3 varieties declined continuously under the stress;and, at 48 h, those of Favorita became significantly lower than those of Xingjia No.2 or Lishu No.6.The soluble protein content and the activities of SOD and CAT in the leaves of the 3 varieties decreased initially but increased afterward.In contrast, POD activity rose at first and followed with a downward trend.Under the stress for 48 h, the soluble protein content and activities of SOD and POD in the leaves of Xingjia No.2 and Lishu No.6 were significantly higher than those of Favorita, while MDA increased constantly during this period.MDA in Favorita was significantly higher than the other varieties.The cold resistance of the cultivars ranked in the order of Lishu No.6, Xingjia No.2, and Favorita.Compared to Favorita, which is the major potato variety cultivated in Guangxi, Lishu No.6 and Xingjia No.2 appeared to be more suitable for winter-planting to extended the growing season in the region.