氮肥运筹对寒地粳稻淀粉合成关键酶活性及淀粉积累的影响

选用寒地粳稻松粳9号和松粳6号，在一定的施肥量下采用不同氮肥运筹处理，对水稻开花后淀粉积累、淀粉合成关键酶活性及其之间的关系进行研究。结果表明，合理减少基肥施氮比例、增加穗粒肥施氮比例可以促进籽粒灌浆、增加总淀粉含量，同时还可适当提高稻米支链淀粉含量。适当减小基肥施氮比例、增加穗粒肥施氮比例有利于提高灌浆后期籽粒中ADPG焦磷酸化酶和淀粉分支酶(Q酶)的活性，而在灌浆前期淀粉合酶(SSS)活性随着基蘖肥比例的减小而降低。通过相关分析可知，ADPG焦磷酸化酶、Q酶和SSS与淀粉及其淀粉组分密切的相关，对淀粉及淀粉组分含量变化均有同等重要的作用。因此: 合理的基肥、蘖肥、穗肥、粒肥配比(5∶3∶1∶1)能够调控灌浆过程中淀粉合成关键酶活性，从而增加淀粉及淀粉组分含量。

Changes in Starch Accumulation and Activity of Enzymes Associated with Starch Synthesis under different Nitrogen Applications in Japonica Rice in Cold Region

The effect of different nitrogen application regimes on rice starch accumulation, starch biosynthetic enzyme activity and the relationship between them after flowering was studied under same N amount with different application periods time, and Songjing 6 and Songjing 9. The results showed that reducing the proportion of base nitrogen fertilizer and increasing the nitrogen fertilizer proportion in grain killing period could promote grain filling, increase total starch content, and appropriately increase amylopectin content. Under different nitrogen applications, the trends and the peak activities of changed of key enzymes associated with starch synthesis were different. In grain filling stage, the activities of ADPG pyrophosphorylase and Q enzyme could be improved significantly by reducing base N and increasing ear-N. In the early grain filling stage, the SSS activity was decreased with decreasing the ratio face fertilizer to tillering fertilizer. the activities of ADPG pyrophosphorylase, Q enzyme, and SSS were significantly correlated the content of starch. Fertilizer application ratio influenced both the content and the composition of starch. Reasonable fertilizer application ratio (5:3:1:1, at processing stage, tillering stage, panicle stage and grain filling stage) could regulate the activities of key enzymes for starch synthesis in different stages and increase contents of starch and starch components.