非结构性碳水化合物积累与小麦植株抗旱性及产量的关系
Relationship Between Non-structural Carbohydrate Accumulation and Drought Resistance and Grain Yield of Wheat

为明确叶片和茎鞘中非结构性碳水化合物（NSC）与小麦植株抗旱性和产量的关系，选用3个抗旱等级不同的小麦品种（‘洛旱7号’‘周麦18’‘西农979’），分别设置干旱和对照处理，研究不同品种叶片和茎鞘非结构性碳水化合物在干旱胁迫下的积累差异及其与产量的关系。结果表明，叶片和茎鞘中可溶性糖质量分数随着花后时间的增加均呈先增加后下降趋势，且均在花后20 d质量分数最高。干旱胁迫下，3个品种叶片和茎鞘中可溶性糖、蔗糖、淀粉及NSC总量均较对照显著增加。不同品种之间表现为，‘洛旱7号’叶片和茎鞘中可溶性糖、蔗糖、淀粉及非结构性碳水化合物质量分数高于其他2个品种；其中在10DAA时，‘洛旱7号’叶片和茎鞘蔗糖质量分数平均较‘周麦18’高8.54%和6.77%，较‘西农979’高0.31%和12.40%。其中干旱胁迫下‘洛旱7号’产量较对照降低13.3%，‘周麦18’和‘西农979’则分别降低39.0%和41.5%。NSC与穗粒质量及产量相关分析表明，开花期茎鞘中蔗糖和淀粉质量分数与穗粒质量、产量显著正相关。说明，提高小麦植株的NSC质量分数特别是茎鞘中质量分数可能有助于缓解小麦干旱，提高干旱胁迫下小麦产量。
In order to understand the relationship between non-structural carbohydrates (NSC) accumulation in leaves,stems and sheaths,and the drought resistance of wheat plants,three wheat cultivars ‘Luohan 7’ (high resistance), ‘Zhoumai 18’ (moderate resistance),and ‘Xinong 979’ (low resistance) were used to investigate the accumulation pattern of NSC in wheat leaves,and stems and sheaths of plant under drought stress and control treatments. The results showed that soluble sugar mass fraction in leaves,stems and sheaths showed a single-peak curve during grain filling stage,and the highest value was observed at 20 days after anthesis (DAS). The soluble sugar,sucrose,starch and total NSC mass fraction in leaves,stems and sheaths were enhanced under drought stress,and cultivar ‘Luohan 7’ got a relative higher accumulation. The average sucrose mass fraction in leaves,stems and sheaths of ‘Luohan 7’ under drought treatment increased by 8.54% and 6.77%,0.31% and 12.40%,compared with corresponding value of ‘Zhoumai 18’ and ‘Xinong 979’ respectively. Compared with corresponding control treatment,drought treatment decreased grain yield by 13.3%,39.0% and 41.5% for ‘Luohan 7’ ‘Zhoumai 18’ and ‘Xinong 979’,respectively. The correlation analysis showed that sucrose mass fraction ,and starch mass fraction in stems and sheaths were positively correlated with spike grain mass and grain yield. The results suggested that increasing NSC accumulation in wheat plants,especially in the stem and sheath,would help to improve plant drought resistance and to increase grain yield under drought stress.