Effects of Recurrent Parents and Introduced Xa1, Xa2 and Xa3 Genes on Rice Grain Quality

Abstract

With 3 diferent recurrent parents (RPs) (‘Suwon 345’, ‘Iri 390’ and ‘Milyang 95’) and 3 diferent donor parents (‘Dae-cheongbyeo’, ‘RantaiEmas’ and ‘Chugoku 69’ for Xa1, Xa2 and Xa3, respectively), 9 near isogenic lines (NILs) were developedand subjected to the analysis of grain qualities and physicochemical properties including milling characteristics and patterns forXa1, Xa2 and Xa3 genes compared with each RP variety. Significanteffects of RPs (A), NILs (B) and their interaction (A×B) were found on the grain appearance (grain length, grain width, grainthickness and length/width ratio), miling ratio, 1000-grain weight, protein and fatty acid contents, peak, hot and cool viscositiesluesrevealed marked RP variation. Alkali spreading value showed significant effects on the RPs and NILs. Mg/K ratio revealedmarked RPs and RPs×NILs interaction variation. On the other hand, milled/brown rice ratio and the gelatinization temperature(GT) showed no significance on the RPs, NILs and RPs×NILs interaction. RPs greatly influenced the determination of grain qual-ity, milling characteristics, cooking and eating qualities of NILs. Therefore, the choice of RPs plays a critical role in backcrossbreeding programs. On the other hand, it is assumed that Xa1, Xa2 and Xa3 genes have not negative effect for the characteristicsassociated with grain qualities and taste of cooked rice.