【作者】 胡慧芳；

【导师】 马有会；

【作者基本信息】 辽宁师范大学 ， 植物学， 2008， 硕士

【摘要】 本论文以黄瓜幼苗作为实验材料,测试黄瓜在干旱、盐碱和低温环境胁迫条件下的若干生理指标,比较不同浓度海藻糖处理后对提高黄瓜幼苗抗逆性的作用效果。研究结果表明:1.用PEG6000模拟干旱条件,海藻糖处理后可提高干旱胁迫下黄瓜幼苗叶片的相对含水量和叶绿素的含量,降低电导率和MDA的含量,提高POD、CAT和SOD酶的活性。说明海藻糖可缓解干旱对黄瓜幼苗生长的胁迫。差异显著性测定后比较海藻糖各处理的效果,浓度为10mmol·L^-1的处理效果好于低浓度的处理。2.在180 mmol·L^-1的NaCI胁迫下,分别添加5、10、20 mmol·L^-1海藻糖的处理都可提高黄瓜幼苗的叶片相对含水量和叶片叶绿素含量,降低细胞质膜通透性和MDA含量,提高POD和CAT酶的活性。这些数据说明添加海藻糖可减轻盐分胁迫对黄瓜的伤害。差异显著性测定表明,在5、10、20 mmol·L^-1的海藻糖处理浓度中,10 mmol·L^-1的处理效果最好。3.在4℃低温胁迫条件下,海藻糖处理后测定黄瓜芽苗根和三叶期幼苗叶片的有关生理指标,结果表明海藻糖处理可降低两种材料的细胞质膜通透性和MDA含量,提高POD和CAT酶的活性,提高幼苗叶片的叶绿素含量。说明用外源海藻糖处理黄瓜幼苗可减轻低温胁迫对幼苗的伤害,而且在黄瓜幼苗的两个不同生长时期得到了一致的结果。差异显著性测定表明,与对照相比,10 mmol·L^-1海藻糖处理对于黄瓜冷害胁迫的抗性具有显著效果。本研究测定结果表明了一定浓度的海藻糖溶液预处理黄瓜幼苗可提高其在低温、高盐以及干旱胁迫下的抗逆性。关于提高黄瓜幼苗对于抗旱性以及耐冷性的海藻糖最适浓度,我们正在设计实验,旨在通过进一步的研究得出较为明确的结论。关于海藻糖提高黄瓜抗逆性的生理机制以及生产应用技术将成为今后研究的重要课题。更多还原

【Abstract】 The paper tested several main physiological indexes of cumuber under separately abiotic stress including drought injury, salt injury, and chilling injury, to study that trehalose solution of adapive concentration had the ability of improving the stress resistance of cumuber. The results are followed.The firstly, under drought injury with PEG6000, trehalose solution of adapive concentration improved relative water content and chlorophyll content of cucumber leaves, and increased the activitives of peroxidase （POD） and superoxide dismutase （SOD） and catalase （CAT） of cucumber leaves and reduced cell membrane relative permeability and MDA content. These showed that the trehalose solution of adapive concentration had the ability of reducing the drought injury of cumuber. Among several different treatments, the effect of 10mmol.L^-1 treholase solution was better.The secondly, under salt injury of 180 mmol.L^-1 NaCI, these treatments including 5, 10, 20mmol.L^-1 trehalose solutions improved relative water content and chlorophyll content of cucumber leaves, and increased the activitives of peroxidase （POD） and catalase （CAT） of cucumber leaves and reduced cell membrane relative permeability and MDA content. These dataes showed that trehalose solution of adapive concentration reduced salt injury. Distinct tests showed that among the three solutions, 10 mmol.L^-1 was the best.The last, under chilling injury of 4℃, the treatment of 10 mmol.L^-1 improved relative water content and chlorophyll content, and increased the activitives of peroxidase （POD） and catalase （CAT） and reduced cell membrane relative permeability and MDA content. Further more, the result of cumuber seedlings was the same as that of cumuber gemma. These showed that the trehalose solution of 10 mmol.L^-1 improved the chilling resistance of cumuber.These studies showed that the trehalose solution of adapive concentration improved the chilling resistance,drought resistance and salt resistance of cumuber. The next experiments will be done about the most adapive solution that trehalose solution improve stress resistance of cumuber, and the physiological mechanism of stress resistance.更多还原