Contribution of RAPD Markers for the Accumulation of Total Silicon in Various Plant Parts of Aerobic Rice (Oryza sativa L.)

Silicon is a major constituent of plant tissues, although not considered to be an essential nutrient, present in consistently high amounts in the terrestrial plants. Silicon has been found to be associated with various abiotic and biotic stress resistance mechanisms especially drought and blast disease in rice. A significant amount of variation was observed in the accumulation of silicon among 85 diverse rice genotypes under study in leaves at flowering and maturity stage as well as in rice grains. A set of 74 RAPD markers that were polymorphic across the 85 diverse genotypes were scored. Single marker analysis (SMA) and stepwise multiple regression analysis (SMRA) was used to determine the extent of markers associated with silicon accumulation in rice. Among the various RAPD markers, SMA established association of four RAPD markers among which OPC14₁₉₀₀ alone contributes to 3.89% while in SMRA, OPD8₁₀₀₀ and OPC14₁₉₀₀ showed more than 11% contribution for silicon accumulation in leaves at flowering stage. For the accumulation of silicon in leaves at maturity stage, SMA established association of five RAPD among which OPD9₁₄₀₀ contributing 5.71% and SMRA revealed OPD9₁₄₀₀ contributing 6.74%. In SMA, OPE7₁₉₀₀, OPE1₇₀₀ and OPB8₁₂₅₀ contributed more than 18% towards silicon accumulation in rice grains. Taken together, our result suggests the existence of genotypic variation in silicon accumulation in rice genotypes and is also developmentally regulated and the markers identified here could be validated and used to determine their linkages with these traits on a segregating populations.