Rice Varietal Purity Test by Using Molecular Marker

Abstract

The purity test of rice variety by using molecular marker or DNA fingerprinting is the most accurate method. Molecular marker technology could detect polymorphism between rice varieties. After milling the DNA extraction from rice leaves is not possible because milled rice seeds are not able to germinate due to loss of the embryo during milling process. Therefore, the varietal purity test requires extraction of DNA directly from a single milled rice seed. This method is difficult because the major composition of milled rice seeds is starch with low DNA content. In this study, we developed a very simple, rapid, convenient and economic feasible DNA extraction method from a single milled rice seed, which includes Proteinase K in SAD extraction buffer and 2x CTAB. Yield and quality of DNA extracted from a single milled rice seed was not different from those of leaf samples and also sufficient for DNA fingerprinting. In addition, we had surveyed and analyzed some SSRs markers for rice varietal purity test. Three SSRs markers for varietal purity test are 1) BO3, which completely co-segregate with the rice grain aroma QTL, 2) RM190, which is closely linked to waxy gene and 3) Glu23, which is Wx allele-specific marker.