Mapping the Gene for Aroma in Rice (Oryza sativa L.) by Bulk Segregant Analysis via RAPD Markers

The sensory qualities of food such as aroma, taste, and texture are the most important criteria for distinguishing Basmati type rices from non-Basmati types. To map the gene(s) controlling aroma, bulked segregant analysis (BSA) using Random Amplified Polymorphic DNA (RAPD) markers was applied in an F2/F3 population of Basmati 370 (aromatic) and IR36 (non-aromatic). DNA samples from homozygous aromatic and homozygous non-aromatic plants identified on the basis of progeny tests were bulked and used for BSA. A total of 550 random primers were used and the primers, AG8 and AN1, produced polymorphism between aromatic and non-aromatic types. Association of AG8- AR, AN1-AR1, and AN1-AR2 with a gene for aroma was determined by surveying F2 individuals. The three RAPD markers AG8-AR, AN1-AR1, and AN1-AR2 were found to be linked to the gene for aroma with a distance of 6.9, 8.9 and 16.4 cM, respectively. Southern analysis with AG8-AR as a probe with 125 F2 individuals confirmed linkage between AG8-AR and the gene for aroma. AG8-AR was mapped on chromosome 8 flanked by two tightly linked markers, RZ617 and RG978, at 2.1 and 1.7 cM distances, respectively, indicating that this gene in Basmati 370 is located on chromosome 8.