外源蔗糖对马铃薯高温与低温胁迫耐受性的影响

发布时间：2018-04-10 23:41

  本文选题：蔗糖 + 高温　； 参考：《兰州理工大学》2017年硕士论文

【摘要】：近年来,随着全球变暖的加剧,低温和高温等极端天气的发生愈加频繁。温度的异常变化严重影响农业生产和发展。马铃薯是我国四大主粮之一,高温和低温逆境是影响马铃薯生长发育的主要因素。蔗糖是光合作用的主要产物,在植物的生长发育中具有重要的作用。胁迫条件下,较高浓度的蔗糖可以直接作为保护物质,低浓度的蔗糖可以作为代谢底物或信号起作用。为了研究蔗糖对马铃薯低温和高温逆境的缓解作用,本实验以马铃薯幼苗为材料,经外源蔗糖预处理1天之后分别用于低温和高温胁迫处理,测定相关生理生化指标,分析蔗糖提高马铃薯低温和高温耐受性的机制。主要结果如下:(1)经42℃高温胁迫11个小时后,蒸馏水处理的对照组和山梨醇处理组出现叶片萎蔫,茎杆失水倒伏,而蔗糖处理的幼苗依然茎杆挺直,叶片也未出现失水的现象;(2)经4个小时-2℃低温处理后,山梨醇处理组和对照组出现严重冻伤,茎杆呈水渍状,叶片颜色加深,蔗糖处理过的幼苗依然保持叶片鲜绿,柔软有弹性;(3)在高温和低温胁迫下,蔗糖预处理能降低叶片丙二醛含量和相对电导率从而降低膜的损伤;(4)蔗糖预处理能够降低高温和低温胁迫下马铃薯叶片H_2O_2的含量,降低马铃薯叶片O_2~(.-)的产生速率,从而减轻了叶片的氧化损伤;蔗糖预处理增加了高温和低温下马铃薯叶片SOD、POD、CAT和APX酶的活性,缓解了温度胁迫造成的氧化损伤;(5)蔗糖预处理增加了高温和低温胁迫下叶片蔗糖含量和总糖含量;蔗糖预处理增加了高温胁迫下叶片脯氨酸和可溶性蛋白的含量;综上所述,蔗糖预处理马铃薯幼苗可降低其体内ROS和MDA的水平,提高抗氧化酶活性,并能增加脯氨酸、可溶性糖以及可溶性蛋白的含量,从而提高了马铃薯幼苗对低温和高温的耐受性。
[Abstract]:In recent years, as global warming intensifies, extreme weather such as low temperature and high temperature occur more and more frequently.Abnormal temperature changes seriously affect agricultural production and development.Potato is one of the four main grains in China. High temperature and low temperature stress are the main factors affecting the growth and development of potato.Sucrose is the main product of photosynthesis and plays an important role in plant growth and development.Under stress, sucrose at higher concentration can be used as protective substance directly, and sucrose at low concentration can act as metabolic substrate or signal.In order to study the mitigation effect of sucrose on potato seedlings under low temperature and high temperature stress, potato seedlings were pretreated with exogenous sucrose for 1 day, respectively, and the physiological and biochemical indexes were measured.The mechanism of sucrose increasing tolerance to low temperature and high temperature in potato was analyzed.The main results were as follows: (1) after high temperature stress at 42 鈩，

本文编号：1733490