Association of Phenotypic Traits and Variations in SSR Markers for Rice Grain Fragrance and Metric Traits Under Different Soil Fertility Regimes

Abstract

Fragrance in rice (Oryza sativa L.) is an important quality trait. This study was conducted to determine the association between variations in fragrance and in SSR markers, and to establish gene action for fragrance. Nine parents and 72 F2 populations generated by full diallel mating design, planted in a nine by nine alpha lattice design at KARI-Mwea Tebere Research Centre, were used for the study. DNA analysis was done using SSR markers RM223 and RM284. The results indicated that RM223 was polymorphic among the parents, while RM 284 gave monomorphic results. Four alleles of RM223 (146, 155, 161, and 163) were detected. Test for independence using Chi-square indicated that there was no association between fragrance phenotype and RM223 marker. The additive gene action was greater for the fragrance score. The general combining ability was about one and halftimes higher than interactions specific combining ability (SCA). The performance of the fragrant lines was generally lower than that of non-fragrant ones, indicating that aroma genes have negative interaction for yield. There was generally negative effect between fragrant score and other agronomic traits such as grain yield across the three soil N and P fertility conditions. The NERlCAl was found to be a good donor for fragrant based on phenotypic (sensory) tests and is a potential genotype for improvement of rice.