Preliminary Attempt for the Development of a Molecular Marker Based Map of Coconut Genome

Abstract

A self-pollination programme has been carried out at the Coconut Research Institute (CRl) of Sri Lanka to produce F2 families of an FJ cross between tall and dwarf coconut palms. Among the F, families generated three were selected for studying the segregation of molecular markers. Simple sequence repeat (SSR) markers were used for the study due to its high level of heterozygosity, codominant inheritance and PCR-based detection. Thirty five SSR primers were used and screening of polymorphic SSR markers was performed by testing the markers on the parents and FJ individuals ofthe progeny. Among the 35 pairs of primers tested 24 exhibited heterozygocity and gave a consistent pattern of SSR alleles in the segregating populations. 173 individuals of F, population were genotyped using these selected 24 primer pairs. Unexpected banding patterns were observed in these 3 families and the data were inadequate to submit to the mapping software JOINMAP for construction of linkage re lati onsh ips. This preliminary study helped to realize the potential of mapping the coconut genome and the need to prepare for genome mapping by construction of segregating populations with utmost care.