Marker Associations with Starch Paste Viscosity Profiles in Rice Independent of Apparent Amylose Content.

Apparent amylose is considered the most important factor in determining rice cooking quality. However, certain varieties with similar apparent amylose contents have different cooking quality responses. A mapping population was developed from a cross of Cocodrie (CCDR) and Dixiebelle (DXBL) which have a similar apparent amylose content of 26% but present different starch viscosity pasting profiles as measured by RVA. Studies were conducted to elucidate the differences between CCDR and DXBL regarding the RVA parameters and associations with microsatellite markers at the the Waxy gene (RM190) and a SNP in exon 10 of the Waxy gene and at the starch soluble synthase gene (AB26295). Brown rice was used for DNA extraction using Qiagen Kit. PCR was used for amplification followed by evaluation for polymorphisms using ABI sequencer.  Marker association studies revealed that the Waxy microsatellite and the Waxy exon 10 SNP markers were associated with soluble amylose and RVA characteristics. These markers will speed up the selection of rice with desirable cooking quality characteristics.