Analysis on the function of alleles of good grain filling contributing to the improvement of grain filling ability of rice extra-heavy panicle types

探索了改善超重穗型水稻灌浆不良的灌浆良好等位基因。结果，在adp葡萄糖焦磷酸化酶（AGPase）小亚基2 （OsAGPS2）、大亚基2 （OsAGPL2）和蔗糖转运蛋白1 （OsSUT1）位点分别检测到APS2-2、APL2-2和SUT1-1作为候选等位基因。具有这三个等位基因的品种在胚乳发育中表现出较高的AGPase活性，成熟后籽粒灌浆程度较高。在这3个等位基因中，APL2-2对籽粒灌浆的影响可能最大。这三个等位基因在籼稻品种中倾向于同时包含。因此，应在籼稻品种中寻找灌浆良好的等位基因，以解决灌浆不良的问题。但这些等位基因不能直接促进产量的提高。

Alleles for good grain filling contributing to the improvement of poor grain filling in extra-heavy panicle types of rice were explored. As a result, APS2-2, APL2-2 and SUT1-1 at the locus for ADPglucose pyrophosphorylase (AGPase) small subunit 2 (OsAGPS2), large subunit 2 (OsAGPL2) and sucrose transporter 1 (OsSUT1), respectively, were detected as candidate alleles. The cultivars with all of these three alleles showed higher AGPase activity in developing endosperm, and higher degree of grain filling at maturity. Among these three alleles, APL2-2 might display the highest effect on grain filling. These three alleles tended to be included together in indica cultivars. Therefore, alleles for good grain filling should be searched among indica rice cultivars to serve the poor grain filling problems. However, these alleles could not contribute directly to higher yield.