Grain Quality of Primal Parental Lines in Hybrid Rice Breeding

Grain quality of primal parental rice lines is a key element for evaluation in breeding new varieties. This article presents the results of a population structure-based analysis on the quality of 274 primal parental lines of hybrid rice used in China and abroad. It was found that, in general, the average brown rice yield and the transparency, gel consistency and amylose content (AC) of the grains of indica rice exceeded the grading criteria for the 3^rdquality tier. For japonica rice, the brown rice yield, head milled rice rate, and the transparency, gel consistency and AC of the grains met the high quality criteria.The percentages of indica that showed superior quality indices varied between 27.7% to 97.7% among all; while japonica, 16.7% to 100%. Grain chalkiness were low for all indica and japonica. Among indica, chalkiness and AC needed the greatest attention for improvements onthe restorer as well as the maintainer lines; AC was good on the conventional rice; and, the overall quality of IR43 and GIZA 178 tropical indica was considered excellent for breeding purposes. In all, 23 primal parental lines were found to have all 10 quality traits graded as high, or higher than, the 3^rd tier. Hence, they could be potential candidates for breeding new rice varieties. As for the deficiency on grain chalkiness, it was recommended that specific germplasms with the desirable trait be introduced for breeding to mitigate the shortcoming in the future.