Rice (Oryza sativa) plants acquired excess photosynthates in the form of nonstructural carbohydrates (NSCs) in their stems and grain. Despite keen interest in rice NSC, the dynamics of NSC accumulation, translocation and re-accumulation have not yet been well investigated. AG1 and AG2 QTLs associated with flooding tolerance through catalyzing starch into soluble sugar in germinating seeds. Here we conducted three experiments, greenhouse and field to lay the groundwork for large-scale diversity studies on grain NSC and some agronomic traits under direct-seeded rice (DSR) system, using elite lines incorporating AG1, AG2 and AG1-AG2 QTLs into the popular varieties PSB Rc82 and Ciherang-Sub1 along with the donors Kho Hlan On (AG1) and Ma-Zhan Red (AG2). In germinating seedlings, soluble sugars increased, while starch concentration decreased gradually especially in the tolerant checks and AG1-AG2 introgression lines under flooded soil. Soluble sugar accumulation in stem started to increase from the vegetative stage and peaked at the panicle initiation stage then gradually decreased towards the maturity stage. But Sub1-AG lines had higher sugar and starch concentrations at different growth stages than other genotypes in wet season 2016 and dry season 2017. Plant survival rate was positively correlated with the stem NSC at the early vegetative stage (21 days after sowing), and stem NSC was positively associated with plant height at different growth stages. Among the tested seeding rate, the most suitable seeding rate, 4 g/m² with shallow burial depth (0.5 cm), resulted in better seedling establishment, relatively higher seedling vigor index and higher leaf area index under flooding in DSR system. Introgression of AG1-AG2 QTLs had no any negative impact on nonstructural carbohydrate, germination rate, and growth and biomass production.

水稻（Oryza sativa）植物的茎和谷粒中以非结构性碳水化合物（NSC）的形式获得了过量的光合产物。尽管人们对水稻的NSC表现出了浓厚的兴趣，但尚未对NSC积累，转运和重新积累的动力学进行深入研究。AG1和AG2 QTL通过在发芽种子中催化淀粉转化为可溶性糖来实现耐洪性。在这里，我们进行了三个实验，包括温室和田间试验，这是利用结合了AG1，AG2和AG1-AG2的优良品系为直接播种水稻（DSR）系统下的谷物NSC和一些农艺性状进行大规模多样性研究的基础。将QTL与受欢迎的Kho Hlan On（AG1）和Ma-Zhan Red（AG2）一起纳入流行的PSB Rc82和Ciherang-Sub1 。在发芽幼苗中，可溶性糖增加，而淀粉浓度逐渐下降，尤其是在耐性检查和AG1-AG2中淹没土壤下的渗入线。茎中可溶性糖的积累从营养阶段开始增加，并在穗开始阶段达到顶峰，然后在成熟阶段逐渐减少。但是Sub1-AG品系在不同生长阶段的糖和淀粉浓度在2016年雨季和2017年旱季比其他基因型更高。在植物生长早期（播种后21天），植物存活率与茎NSC呈正相关，并且茎NSC在不同生长阶段与株高呈正相关。在测试的播种量中，最合适的播种量为4 g / m ²埋深较浅（0.5厘米），在DSR系统中，淹水后秧苗更好地建立，秧苗活力指数相对较高，叶面积指数较高。AG1-AG2 QTL的渗入对非结构性碳水化合物，发芽率，生长和生物量生产没有任何负面影响。