双重化控对春玉米灌浆期穗位叶和籽粒蔗糖代谢关键酶活性的影响

以中单909和吉单35为材料，设置乙矮合剂和聚糠萘合剂双重化控处理，研究玉米穗位叶和籽粒中蔗糖代谢相关酶活性的动态变化，探讨双重化控调控玉米碳代谢的生理机制，为建立玉米高产稳产的化学调控技术提供理论基础。结果表明，双重化控提高了灌浆期穗位叶蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性，尤其显著提高灌浆后期(花后50 d)蔗糖合成能力，提高灌浆前期(花后10~20 d)穗位叶蔗糖含量，降低后期(花后30~50 d)蔗糖含量。双重化控处理对玉米籽粒蔗糖合成酶(合成方向)和蔗糖磷酸合成酶活性的影响较小，蔗糖合成酶分解方向活性呈升高趋势；中单909籽粒蔗糖含量灌浆前期(花后10 d)升高，灌浆后期(花后50 d)降低，花后20~40 d影响不显著，吉单35籽粒蔗糖含量花后10~20 d降低，30~40 d升高，50 d没有显著差异。双重化控处理提高了中单909和吉单35灌浆中期和灌浆中后期灌浆速率，使两品种粒重和产量均显著提高，分别比对照增产4.61%和7.78%。本研究说明，乙矮合剂和聚糠萘合剂双重化控处理可通过调控源库蔗糖代谢关键酶的活性，促进蔗糖在源端的合成和在库端的降解，从而促进碳同化物向籽粒的转运，达到高产。

Effect of Plant Growth Regulators on Key Enzymes in Sucrose Metabolism of Ear Leaf and Grain at Filling Stage of Spring Maize

In order to explore the new cultivation techniques, chemical control was established inthis study.We conducted a field experiment using two varieties of Zhongdan 909 and Jidan 35with treatments of leaf-sprayingethylene-chlormequat-potassium (ECK) in V6, andPASP-KT-NAA (PKN) in V9. The results showed that ECK & PKN increased the activities of sucrose synthetase(SS)and sucrose phosphate synthetase (SPS) and sucrose content during early grain filling stage (10-20 d after anthesis)in ear leaf, and decreased sucrose content in ear leaf during late grain filling stages (30-50 d after anthesis),especiallyit improved the ability of sucrose synthesis at the late filling stage (50 d after anthesis). ECK & PKN also decreased SS (synthesis) activity in grain during middle and late grain filling stages and increased SS (resolving) activity, promoting sucrose decomposition ability, withless effect on SS(synthesis) and SPS activitiesin grain. The yields of Zhongdan 909 and Jidan 35 compared with their own control were respectively increased by 4.61% and 7.78%.The studyindicated that ECK & PKN enhance sucrose synthesis in leaf and decompositionability in grain, andpromote the translocation of carbon assimilation to grain, resulting in highgrain-filling rate,high grain weight, and high yield.