Analysis of Yield and Quality Traits and Their Relationship in Japonica Rice in Northern China
WANG Yan-Zheng;WANG Xiao-Jing;LI Yuan;XU Hai;WANG Jia-Yu;ZHAO Ming-Hui;TANG Liang;MA Dian-Rong;XU Zheng-Jin;CHEN Wen-Fu;Rice Research Institute, Shenyang Agricultural University/Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province/Key Laboratory of Northeast Rice Biology, Genetics and Breeding, Ministry of Agriculture;
As the scientific rice research develops and the standard of living improves, the demand for japonica rice has been consistently increasing and the planting area of japonica rice has been enlarged over times. Hence, a further investigation on the differences of yield and quality traits among different planting area and the relationships between yield and quality of japonica rice varieties can provide valuable guidance for rice breeding in northern China. In this study, we analyze the data collected from the regional rice tests of northern China in 2011 and 2012. Based on the feature of the regional climates and the characteristics of the lines/varieties tested, we divided the lines/varieties tested we divided into five groups, including Huang-Huai japonica group, Beijing-Tianjin-Hebei japonica group, late-maturity mid-early japonica group, medium maturity mid-early japonica group, and early-maturity mid-early japonica group. Then, we analyzed the differences of the yield, yield components, quality traits and their relationships among the five groups. The yield of the mid-early japonica group with medium maturity was the highest; while the yield of the mid-early japonica rice with late-maturity was the lowest in the five groups. The mean rate of brown rice and the mean rate of head rice of the five groups were 83.66% and 66.95%, respectively. The rate of chalky rice and chalkiness degree were 30.26% and 3.08%, respectively. The yield significantly and positively correlated to the rate of brown rice, the rate of milled rice and the rate of head rice. The percentage of seed setting exhibited a significantly positive correlation to the ratio of brown rice, the ratio of milled rice, and the ratio of head rice, but a significantly negative correlation to the rate of chalky rice. Although the ratio of grain aspect showed a negative correlation to the ratio of brown rice and the ratio of head rice, the ratio of grain aspect was not closely related to yield. The density of seed setting had a significant and negative correlation to the number of panicle, but a significant and positive correlation to the number of grains per panicle, so that the density of seed setting was not closely related to yield. There were no significant correlations between the density of seed setting and the rate of seed setting, thousand grain weight, and chalkiness related traits. The results indicated that the yield can be increased at least to 9 t ha–1 without sacrificing the grain quality in northern China. It is feasible to improve quality based on maintaining high yield, or increase the yield based on maintaining high quality of rice, thus achieving a balance between the yield and quality at a higher level.