Detection of a New Genetic Locus of Rice Floury Mutant Using Whole Genome Re-Sequencing

Producing rice flour of good quality by dry milling is necessary to reduce milling costs and promote the processed rice food industry. This study was conducted to evaluate the dry milling properties of a floury endosperm mutant and identify the chromosomal region responsible for the floury endosperm characteristics. Compared with the wild type, after dry milling process, the grain hardness of the mutant was significantly lower because of its round and loosely packed starch granules. Also, the flour of the mutant had significantly smaller particles and less damaged starch than original variety and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar.

In previous study, the floury endosperm of the mutant was directed by a major recessive locus located in the 19.33–19.86 Mbp region of chromosome 5. By whole genome re-sequencing, we detected SNPs between original variety and mutant and developed CAPs marker for those SNPs. Now we validate the SNP tagged the new rice floury locus and design CAPs marker. Further analysis with modifying allele type among rice germplasm, we confirm molecular marker for the floury locus. Further physical mapping of the floury endosperm locus of the mutant, would facilitate efficient breeding of rice cultivars with proper dry milling adaptability that can be used in the processed rice food industry.