Molecular screening of yield component QTLs for strong culm, grain number and grain width using gene specific markers in indica- tropical japonica derived rice lines

Abstract

Rice varieties with 20% yield advantage over present day popular varieties have to be developed in order to meet the growing demand. Yield is a polygenically controlled complex trait. Three major characters like high grain number, grain weight and strong culm are necessary in order to increase the yield potential of rice. In this study, ninety five indica-tropical japonica derived rice lines were screened for the presence of yield QTLs, the main objective being identification of donor lines to improve the popular varieties by marker-assisted breeding
programme. Three functional markers namely Gn1a, GW2 and SCM2 were used to validate the presence of the yield QTLs. Thirty six genotypes namely CR2674-24-1-1-1, CR2674-24-1-2-3-1, CR2688-6-3-1-1-2, CR2667-1-
9-5-1-1, CR2667-1-9-5-2-1, CR2667-9-2-4-1-1, CR2667-9-2-4-1-1-2, CR2683-46-5-6-1-1-1, CR2683-46-5-6-1-1-1-2-1, AC38700, AC 38790, AC38687, CR-978-3-2, CR-2080-16-17-6-2-1, CR-2251-3-4-3-1, CR-2608-5-3-1-1, CR-2683-45-1-2-2, CR3813-3-3-1-1-1, CR3820-1-7-1-1-1, CR3820-5-3-1-1-1, CR2683-45-1-2-1-1, CR2683-45-1-2-1-2, CR2682-1-1-5-1-2, CR2683-46-5-8-3-3, CR2683-46-5-8-3-1, CR2683-46-5-8-3-2, CR 3696-5-5-2-2-1, CR 2682-1-1-5-1-1, CR2687-13-5-7-1-2, CR 2681-5-2-1-1-1, CR2683-46-5-2-1-1, CR 3818-1-1-1-1-1, CR3598-1-4-2-1-1, CR 2678-2-1-1-1-1, CR3696-5-5-2-1-1 and CR2683-46-5-9-1-1 showed the presence of three yield QTLs for high grain number (Gn1a), strong culm (SCM2) and grain weight and width (GW2). These three QTLs may contribute significantly towards yield enhancement of rice. However,phenotypic confirmation is required because of wide allelic variations in the traits under study.