Tanzania Agricultural Research Institute

Author(s) : Ally Mwichande Russinga1, A. Srividhya2*, V.L.N. Reddy1 and P. Latha2

Abstract

The knowledge of functionally characterized genes and linked markers that govern grain yield and its related traits were used to unravel the markers/genes that associate with diversity of yield traits in a panel 30 novel rice genotypes comprising of indica, japonica, aromatic, landraces, interspecific crosses (O.glaberrima/O.sativa) etc. The ANOVA showed significant differences (P=<0.001) for all traits among the genotypes. Molecular analysis was done by employing 37 gene-specific markers targeting 24 yield governing genes in rice. Two markers viz., RM223(YLD) on chromosome 8 and GW004(GW2, LOC_Os02g14720) on chromosome 2 were identified as polymorphic. Average PIC (polymorphic information content) value for these primers was 0.37, suggesting the availability of accountable variability at these loci. Cluster analysis grouped the genotypes into three clusters. Marker-trait-association analysis revealed significant association of the marker GW004 with panicle length, plant height and filled grains in rice. Pearson correlation study also supported the molecular associations through significant phenotypic associations for trait pairs plant height and filled grains, panicle length and plant height. The phenotypic variance explained (R2%) by the marker across panicle length, plant height and filled grains was ≥15%, suggesting major role of the locus/gene in controlling respective traits. Thus, GW004 marker could be employed in breeding programs for simultaneous selection of three traits panicle length, plant height and filled grains. From the current study it can be concluded that allelic variation studies using novel genotypes can result in the identification of suitable donors along with trait associated markers for rice yield improvement.

Keywords: Rice, gene tagged markers, Allelic variation, Association study, GW2 gene