干旱胁迫对小麦非结构性碳水化合物代谢的影响及其与抗旱性的关系

摘要

为了研究干旱胁迫下，小麦非结构性碳水化合物的改变率与干旱敏感系数的相关性。利用室内水培的方法，以6个抗旱性不同的小麦品种为试验材料，设置15% PEG和20% PEG 2个胁迫水平，以不添加 PEG 的正常营养液为对照，系统研究了不同干旱胁迫条件下小麦叶片和根系中主要非结构性碳水化合物含量的变化规律。结果表明，干旱胁迫明显降低了各小麦品种干物质量，6个小麦品种在不同干旱水平下的抗旱性均表现为晋麦47>矮抗58>周麦22>洛旱6号>郑麦9023>西农979；干旱胁迫下6个小麦品种叶片和根系中可溶性总糖、蔗糖、果糖、葡萄糖含量均随着干旱时间的增加呈先增加后降低的趋势，而淀粉和果聚糖含量则呈降低的趋势，复水后各非结构性碳水化合物含量逐渐恢复到对照水平；6个小麦品种中，干旱敏感性越高的品种，在干旱胁迫下其组织中各非结构性碳水化合物含量的改变率越小；干旱敏感系数与干旱胁迫下各非结构性碳水化合物含量的改变率均呈负相关性，其中可溶性总糖、果糖、淀粉、果聚糖含量在干旱胁迫下的改变率与干旱敏感系数的相关性达到显著水平。在干旱胁迫下，淀粉与果聚糖的水解对提高小麦抗旱性有重要作用。%In order to study the relationship between non-structure carbohydrate and drought sensitive coeffi-cient under drought stress. The variation of non-structure carbohydrate contents in leaves and roots of six wheat vari-eties were studied under two dought stress treatments(15% PEG and 20% PEG),taking the normal solution man-agement as control( CK ). The results displayed that the dry matter weight decreased under drought stress. The drought sensitivity of six wheat varieties was Jinmai 47(JM47)>Aikang 58(AK58)>Zhoumai 22(ZM22)>Luohan No. 6(LH6)>Zhengmai 9023(ZM9023)>Xinong 979(XN979)for both 15% PEG and 20% PEG treatments. The contents of total soluble sugar,glucose,fructose and sucrose increased first and then decreased with the extension of drought stress time,while the contents of starch and fructan decreased all the way. The non-structure carbohydrate contents in leaves and roots approximated the level of CK after rewatering. The varieties with higher drought sensitiv-ity had less change rate of non-structure carbohydrate contents. The drought sensitive coefficient had negative corre-lation with the change rate of non-structure carbohydrate contents. The correlations of drought sensitive coefficient with the change rate of soluble total sugar,fructose,starch and fructan was significant. The degradation of starch and fructan under drought stress played an important role in improving the drought resistance of wheat.