Correlation between length and quality of grain in Indica rice and its application in breeding

Grain length is closely related to grain qualities in Indica rice，including appearance，cooking， nutrition and milling，and positively correlated with appearance and cooking quality，along with a negative correlation with milling quality. The grain length influences nutrition quality to some extent by lowering its content of proteins and amino acids，and it is an important characteristic that determines its class as well as commodity price，with longer length being accompanied by higher quality. Grain length is investigated as a quantitative trait and may also be affected by environmental factors，but its key determinant is the genotype of itself，suggesting that it is feasible to breed up a quality rice variety by genetically improving the trait of grain length. The paper reviewed the correlation between grain length and grain qualities，genetic study on grain length trait，and their applications in quality rice breeding.