四川盆地东南部再生稻开花期受低温冷害的风险预测

为准确预测不同区域再生稻开花期受自然低温冷害的风险程度,并为开花期耐低温冷害品种的合理布局与制定相应的避（缓）高产稳产技术提供科学依据,于2018年和2019年,以近几年四川省推广的22个杂交中稻品种为材料,分别在四川盆地东南部不同生态点开展试验,研究了基于经度、纬度和海拔高度的再生稻开花期受自然低温冷害风险的预测方法。结果表明,再生稻齐穗后第5日日序与经度呈显著负相关,与海拔呈极显著正相关;建立了基于经度和海拔高度预测再生稻齐穗后第5日日序的回归模型,F检验值为22.88**～65.11**,决定系数高达0.9196～0.9702。该模型经多个品种连续两年在6个生态点验证,实测值与预测值1∶1回归模型的决定系数高达0.8391～0.8638,实测值与预测值之间的均方根差（RMSE）值为0.93%～1.21%,预测值与实测值之间具有较好的一致性。将本研究建立的再生稻齐穗期与地理位置关系模型与作者等先期建立的基于地理位置（纬度、海拔）预测≤22℃最早发生期预测模型相结合,探明了不同地理位置再生稻开花期受低温冷害的机率。利用地理位置信息可准确预测再生稻开花期受低温冷害的风险程度,具有较强的...

Risk Prediction of the Damage of Low Temperature Injury Flowering Period of Ratooning Rice in Southeastern of Sichuan Basin

Accurately predict the risk degree of the injury of low temperature in flowering stage on ratooning rice in different regions is beneficial to properly distributing low-temperature resistant varieties in the flowering stage according to local conditions and establishing high and stable yield technique to avoid or relieve low temperature. In 2018 and 2019, 22 new mid-season hybrid rice varieties introduced in recent years in Sichuan Province were used as materials and a unified test scheme at different ecological sites in southeastern Sichuan Basin were adopted to develop a method for predicting the risk of injury by low temperature in the flowering stage of ratooning rice based on longitude, latitude and altitude. The result showed that, the sequence of the 5th day after full heading of rationing rice was negatively correlated with longitude while positively correlated with altitude. A regression model based on longitude and altitude was established to predict the sequence of rice on the 5th day after full heading of rationing rice, in which the F value was 22.88^**~65.11^**, and the coefficient of determination was 0.9196~0.9702. The model was validated on several varieties at 6 ecological sites for two consecutive years. The determination coefficient of 1:1 regression model between measured value and predicted value was 0.8391~0.8638, and the RMSE between the measured value and the predicted value was 0.93%~1.21%. There was a good performance in consistency between the predicted value and the measured value. Combining the relationship model between the full head stage and geographical location of ratoon rice established in this study and the earlier prediction model based on geographic location （latitude, altitude） established by the authors to predict the earliest occurrence period of ≤22 ℃, and clarified the rate of injury by low temperature in flowering stage of ratooning rice in different geographical locations. Information of geographical location is useful to achieve accurate prediction of the risk of low temperature injury in flowering stage of ratooning rice, which has high applicability in production.