低温胁迫下3个甜角品种幼苗的抗寒性研究

以甜角品种PRAKAYTONG(闪金)、SRITONG(金色)、SRITONGBAO(轻金色)的1年生嫁接苗为材料,采用人工气候箱连续15 d分别进行5、10、15、20、25、30℃的温度处理,测定分析了低温胁迫下甜角幼苗叶片与抗寒性相关的生理生化指标。结果表明:20 30℃是甜角生长发育的最适温度范围,当温度下降到15℃时,随着温度的降低,甜角幼苗叶片的相对电导率、丙二醛(MDA)含量、脯氨酸含量、可溶性糖含量呈上升趋势,过氧化物酶(POD)活性表现出先升后降趋势,叶片含水量呈现下降趋势;温度降到10℃时,幼苗叶片上述指标变化加剧,幼苗生长发育受到抑制。在相同的低温条件下,随着处理时间的延长,幼苗叶片的上述6个指标呈现相似的变化趋势,温度越低,变化越剧烈。根据隶属函数法,综合判定3个甜角品种的抗寒性强弱的顺序为:SRITONG>SRITONGBAO>PRAKAYTONG。

Studies on the Cold Resistance of Three Sweet Tamarind Varieties under Low Temperature Stress in Seedling Stage

The cold resistance of 1-year-old grafted seedling of Sweet Tamarind(Tamarindus indica L.)including three varieties of PRAKAYTONG,SRITONG and SRITONGBAO introduced from Thailand were tested for 15 days to measure and analyze the physiological and biochemical indexes of leaf related to cold resistance under treatment temperatures of 5,10,15,20,25,and 30 ℃ separately.The results showed that the optimum temperature range for the growth of Sweet Tamarind was 2030 ℃.When the temperature dropped to 15 ℃,the electrical conductivity,MDA,proline and soluble sucrose contents increased,the activities of POD increased at first and then decreased,while the leaf water content decreased with the decrease of temperatures.When the temperature dropped to 10 ℃,the changes of these indexes were more drastically and the seedling growth was inhibited.The six indexes showed similar changes with the prolonging treatment times of low temperature below 15 ℃ and the lower temperature,the more intense the changes.The integrated assess to the cold resistance magnitude of the three varieties of Sweet Tamarinds is as follows: SRITONG>SRITONGBAO>PRAKAYTONG,based on membership function method.