Exogenous application of methyl jasmonate (MeJA) improves rice drought tolerance, but its effects on rice yield and quality under drought stress during the reproductive phase remain unclear. A pot experiment was conducted to measure rice yield, grain quality, and starch physicochemical properties under three treatments: continuous flooding irrigation throughout the whole growth season (CF), ten days of −40 kPa drought stress at the heading stage (DS), and foliar spraying 100 μmol L⁻¹ MeJA on the first three days of the ten-day −40 kPa heading stage drought stress (DM). An inbred japonica rice variety, Huaidao 5, was the experimental material, and each treatment had 11 replicates for sampling. The results indicated that DS significantly reduced rice yield and quality compared to CF. With increases in superoxide dismutase (+22.2%), peroxidase activities (+10.5%), catalase (+5.0%), and proline content (+5.7%), DM significantly increased 1000-grain weight (+8.6%), filled grain percentage (+3.6%), and yield (+11.1%) compared with DS. Regarding grain quality, DM significantly decreased the chalkiness degree (−12.3%) and protein content (−3.9%) but increased the amylose content (+17.2%) and taste value (+7.3%) relative to DS. In addition, DM improved breakdown viscosity (+17.8%), gelatinization enthalpy (+17.2%), retrogradation enthalpy (+28.0%), 1045/1022 cm⁻¹ ratio (+3.0%), and starch granule morphology compared to DS. In conclusion, exogenous application of 100 μmol L⁻¹ MeJA enhanced the antioxidant capacity of rice leaves, and thus improved starch physicochemical properties to increase grain yield and quality under terminal drought stress.

Potted-seedling machine transplantation (PSMT) is an innovative method of mechanical rice transplanting to improve seedling quality and reduce mechanical injury relative to blanket-seedling machine transplantation (BSMT). However, the responses of yield, grain quality, and risk of lodging in rice to PSMT have not yet been comprehensively defined. Here, we present a meta-analysis of 67 peer-reviewed studies with 382 field observations to investigate the impacts of PSMT on rice yield, grain quality, and lodging resistance in mainland China. The results indicated that compared to BSMT, PSMT increased grain yield, aboveground biomass, and nitrogen uptake by an average of 8.4%, 6.2%, and 7.2%, respectively. PSMT boosted grain yield with hybrid rice (+10.2%) more strongly than with inbred rice (+6.9%). PSMT improved the brown rice rate (+0.74%), milled rice rate (+1.1%), head rice rate (+2.3%), and gel consistency (+4.4%) while reducing the amylose content by 3.7% with no significant effects on the chalky grain rate, chalkiness, length/width ratio, or protein content. The increase in the milled rice rate under PSMT was greater with hybrid rice than with inbred rice. PSMT reduced the lodging index at the first (−5.1%), second (−9.4%), and third (−8.0%) internodes. In conclusion, PSMT is a promising practice for simultaneously improving rice yield, milling quality, cooking and eating quality, and lodging resistance in paddies. In addition, the grain yield and milling quality of hybrid rice under PSMT are higher than those of inbred rice.