Abstract
Rice accumulates very high amounts of Si in shoots. Si may reach levels of up to 10% of shoot dry weight, however, mechanism involved in Si uptake are not well understood. The shoot Si content was similar between two rice cultivars, Nipponbare and Kasalath, but the Si uptake ability was lower in Kasalath. Kinetics study showed that Nipponbare and Kasalath had a similar Km value, whereas the Vmax was higher in Nipponbare. These results suggest that the same transporter for Si is present in Nipponbare and Kasalath, but that this transporter is more abundant in Nipponbare. A QTL analysis for Si uptake was performed in rice using 98 BILs derived from parents Nipponbare and Kasalath. Three QTL for Si uptake were detected on chromosomes 3, 5 and 9. These QTLs explained 47.1% of phenotypic variations in Si uptake. The confirmations of these QTLs are being undertaken by using substitution lines.
