Studies On The Factors Of Influencing Rice Quality Of Early Ripen Japonica Rice In Cold Region

The cold region is a concentrate area for planting japonica rice in China. The rice varieties (lines) which planted in Heilongjiang province in recent years were used and the method of correlation analysis of blast- resistance and rice quality and contrast experiment were adopted in this project. The influence of variety, rice blast and nitrogen element on the quality of early Japonica rice was studied . The purpose was to provide theoritical basis and technical support for high quality rice varieties breeding and cultivation techniques in cold region. The main results are as follows:1. The influence of variety, rice blast and nitrogen element on the quality of early JaponicaRice, rice varieties on rice quality of early ripen japonica rice in cold region is the biggestnext is rice blast and nitrogen element.2. The variability coefficients of chalkiness has great difference among early-ripening and later-ripening varieties, except for mid-ripening varieties. The amplitude of amylose content is normal distribution, its major peak position is at 18.0% to 18.9%. The higher the protein content is, the worst of the taste quality is. It is positive correlation between gel consistency and taste quality.3. The varieties have strong disease-resistant and superior quality when the ratio of grain length to broad is over 1.8. The lower the protein content is, the stronger the rice blast resistance is. The protein content is positively correlated to leaf blast. The correlation coefficient is 0.284. In order to breed varieties with superior taste quality and strong disease-resistance, the comprehensive technology must be used to break the gene linkage between the rice blast and taste quality. The varieties Songjing6, Songjing9, Wuyoudao3, Longdao3, Kendao10, Longjing12 and Longjingl4 are major cultivars and good germplasm resources in Heilongjiang Province.4. The regulative function of nitrogen element nutrition must be taken into account in production and varieties improvement. Protein is greatly effected by nitrogen element nutrition, next is gel consistency.The results would have some remarkable effects on breeding new rice variety with high quality, studying the suitable cultivation techniques,improving the milling rice quality.promoting sale of rice and increasing the economic benefit in the cold region of China.