INHERITANCE OF AROMA IN 6 RICE CULTIVARS

'Jasmine 85', a soft-cooking aromatic rice (Oryza sativa L.) cultivar, was released in the USA with the objective of displacing imported Tha i Jasmine rice in local markets. However, the reduced aroma and off-wh ite color of its milled rice limit its marketability. The present obje ctive was to determine the number of genes controlling aroma in four r ice lines (Jasmine 85, 'Amber', a dwarf mutant from 'Basmati 370' (PI 457917), and 'Dragon Eyeball 100'), and to evaluate the allelism of ar oma in these four lines and with the single recessive gene known to be in both 'A-301' and Della-X(2). Lack of leaf aroma in aromatic/non-ar omatic F-1 hybrids indicated the recessive nature of the aroma in all studied rices. F-2 Segregation ratios revealed that Jasmine 85 and PI 457917 each contain a single gene for aroma, and the aromatic nature o f the F-1 leaves from crosses with each other and with A-301 and Della -X(2) revealed that the aroma genes in all four cultivars are allelic. Amber and Dragon Eyeball 100 each contain two aroma genes, a novel ge ne plus one allelic to the gene in A-301, Della-X(2), Jasmine 85, and PI 457917. Incorporation of a novel aroma gene into Jasmine 85 could p otentially increase its marketability. No linkage was detected between the two aroma genes in Dragon Eyeball 100 and five morphological char acters. High levels of sterility observed in Amber F-2 populations may hinder the use of its novel aroma gene.