田间越冬期不同根型苜蓿根系的生理生化特性

PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERISTICS OF ROOT IN DIFFERENT ROOT TYPE ALFALFA CULTIVARS IN FIELD DURING OVERWINTERING PERIOD

以根茎型清水苜蓿、直根型陇东苜蓿、根蘖型甘农2号杂花苜蓿和野生黄花苜蓿为试验材料,在田间条件下,测定3类根型的4个苜蓿品种(材料)在秋末至翌年初春根系脯氨酸、丙二醛、可溶性糖及可溶性蛋白质含量、过氧化氢酶和超氧化物歧化酶活性6项指标的变化,以研究不同根型苜蓿品种(材料)对低温的适应性。结果表明,4个苜蓿品种(材料)其脯氨酸、可溶性糖、可溶性蛋白质和过氧化氢酶均随着气温下降而增加、随着气温升高而减少;而SOD活性和MDA含量,在不同品种(材料)之间随气温的变化规律不同。运用隶属函数法进行抗寒性综合评判4,个品种强弱顺序为:根蘖型野生黄花苜蓿材料>根茎型清水苜蓿>根蘖型甘农2号杂花苜蓿>直根型陇东苜蓿。

In this paper,4 alfalfa cultivars or materials with three root types（rhizomatous rooted Medicago sativa L.cv.Qingshui,tap rooted Medicago sativa L.cv.Longdong,creeping rooted Medicago varia Martin.cv.Gannong No.2,creeping rooted native Medicago falcata materials） were used to study the adaptability on different alfalfa materials to low temperature and observe the cold resistance.The physiological and biochemical indexes,including free proline,soluble sugar,soluble protein,malondialdehyde,catalase activity and superoxide dismutase activity in root were trace-determined in the field during periods of late fall,winter and spring of next year.Results showed that the content of free proline,soluble sugar,soluble protein and catalase activity in root increased with air temperature fall,and decreased with air temperature rise;the trends of variety superoxide dismutase activity and MDA showed different variations with air temperature drop and rise.Meanwhile,the cold resistance ability of alfalfa varieties were evaluated by using fuzzy mathematics method,the orders of cold resistance as follows： creeping rooted native Medicago falcata material rhizomatous rooted Medicago sativa L.cv.Qingshui creeping rooted Medicago varia Martin.cv.Gannong No.2 tap rooted Medicago sativa L.cv.Longdong.