Effects of combined stress of high temperature and drought at early filling stage on characteristics of yield and after-heading dry matter production of high-quality japonica rice

【Objective】 To study effects of combined stress of high temperature and drought at early filling stage on characteristics of yield and after-heading dry matter production of high-quality japonica rice, to provide theoretical reference for integrated innovation of cultivation technology of high-quality, high-yielding and stress-resistant rice.【Method】 High-quality japonica rice Nanjing 9108 and Fengjing 1606 were chosen as materials, four treatments including high temperature and drought(HD), high temperature with conventional water management(HC), conventional temperature with drought(CD) and conventional temperature with conventional water management(CK) were set during 1-20 d after heading to study the effects of combined stress of high temperature and drought on rice yield and panicle traits, and after-heading dry matter accumulation and transport at early filling stage.【Result】 Grains density, 1000-grain weight, seed setting rate, actual yield and harvest index among different treatments was in the order of HDP<0.01, the same below) in seed setting rate and yield among the treatments. Compared with CD and CK, other indexes were not significantly different(P>0.05, the same below) under HD and HC, which were all significantly different(P<0.05, the same below) or extremely significantly from CD and CK. Except seed setting rate and 1000-grain weight, the difference between CD and CK was not significant. The number of filled grains, filled grains weight, 1000-grain weight and seed setting rate on primary and secondary branches were in the order of HD