Identification and Sequencing of Gene Related to Length of Rice Grain

Objective The gene that regulates the length of a rice grain, which directly relates to crop yield, was identified and sequenced for breed improvement.

Method  Through map-based cloning, 499 recombinant inbred lines derived from the interspecific cross between Jiafuzhan (indica) and Nipponokin (japonica) were employed to identify the quantitative trait loci associated with the phenotypic trait.

Result A major plasmid length of GS3 was 1851 kb, detected in the recombinant inbred line population located approximately within the physical distance 16310–18161 kb. Since only the 48^th base of the second exon was mutated from C to A between the genes of Jiafuzhan and Nipponbare, protein translation was no longer necessary. Further analysis on Jiazao No. 1 and Jiafuxiangzhan bred using the GS3 showed no significant difference than the wild type Jiafuzhan in grain length, width, or length-width ratio.

Conclusion  The long-grain gene GS3 could be detected in the recombinant inbred lines of Jiafuzhan × Nipponbare, and could be stably inherited and applied. The information on GS3 obtained in this study was of value for future studies to genetically improve rice production.