Abstract: Based on the interval sowing trial for high quality rice variety Yixiang 9303 in Chongqing,the regression model for yield and yield components and climatic-ecological model for the yiela components were established by the multivariable step-wise and multi-correlation analysis.The results indicated that the grain per spike,seed setting rate,spikes per unit area and thousand grain weight had great contribution to the yield,especially grain per spike and seed setting rate.There was a significant negative correlation between grain per spike and average temperature in the jointing-booting stage,while the grain per spike had a quadratic regression with the average temperature in the booting-heading stage.The seed setting rate had quadratic regression with the average temperature in the booting-heading and heading-milk stages.The optimum average temperature for the booting-heading and heading-milk stages was 27.2℃ and 26.7℃respectively.The main meteorological factors which influenced the spikes per unit area were the average precipitation and the daily average sunshine hours in the emergence-reviving stage,and the average temperature and the daily average sunshine hours in the reviving-jointing stage.The average maximum temperature in the booting-heading and milk-maturation stages,and the daily temperature range in the heading-milk and milk-maturation stages were the key factors determining the thousand grain weight of the high quality rice.

Key words: High quality rice, High quality rice, Yield formation, Climatic-ecological, Chongqing City