隶属函数法对5种菜用甘薯耐寒性的评价

Evaluation of Cold Tolerance of Five Sweet Potato Varieties by Membership Function Method

为探讨菜用甘薯低温伤害机理并评价菜用甘薯品种耐寒性,以5种菜用甘薯苗为材料,通过人工气候箱模拟低温实验,以25℃为对照,研究在15℃,5℃低温胁迫下其叶片中生理生化的变化,然后利用隶属函数法对其品种间耐寒性进行评价。结果表明:低温胁迫下5种菜用甘薯叶片中相对电导率和丙二醛(MDA)细胞伤害指标升高;过氧化氢酶(CAT)、过氧化物酶(POD)活性、脯氨酸(Pro)、蛋白质、可溶性糖含量均随着胁迫温度的降低而升高。不同品种间各指标大小及变化差异较大。由隶属函数综合评价得出5种菜用甘薯耐寒性强弱顺序为:15℃低温胁迫下,莆薯53>海南本地品种>徐菜薯1号>徐紫菜薯8号>广薯菜2号;5℃低温胁迫下,莆薯53>海南本地品种>徐紫菜薯8号>徐菜薯1号>广薯菜2号。

Low temperature is a major factor restricting cultivation of vegetable sweet potato in winter and spring,in Hainan,China. In order to explore the mechanism of cold injury and evaluate the cold tolerance of vegetable sweet potato varieties,five vegetable sweet potato varieties were chosen as material to determine their physiological and biochemical parameters under the temperatures of 25,15,5 ℃ in the artificial climate chamber,and the resultant data were analyzed by using the membership function method to evaluate the cold tolerance of the varieties. The result showed that five vegetable sweet potato leaves treated at a lower temperature increased their relative electrical conductivity,malondialdehyde（ MDA） cell damage index,and that catalase（ CAT）,peroxidase（ POD） activity,and the contents of proline（ Pro）,soluble sugar and protein increased as the treatment temperature decreased. The parameters and their changes of the varieties were different. The membership function based comprehensive evaluation showed that the five vegetable sweet potato varieties had a cold tolerance in the order of Pushu53 〉Hainan local varieties 〉Xucaishu 1〉 Xuzi caishu 8 〉Guangshucai 2 at the temperature of 15 ℃;Pushu53〉 Hainan local varieties〉 Xuzicai 8〉 Xucaishu 1〉 Guangshucai 2 at the temperature of 5 ℃.