EVALUATING GENETIC-RELATIONSHIPS BETWEEN INDIGENOUS COCONUT (COCOS-NUCIFERA L.) ACCESSIONS FROM SRI-LANKA BY MEANS OF AFLP PROFILING

PCR-based DNA profiling of coconut palms indigenous to Sri Lanka was c onducted using amplified fragment length polymorphism (AFLPs). A total of 322 amplification products were generated from the 42 genotypes wi th eight pairs of primers (EcoRI and MseI). Overall most variation was detected in the tail (Typica) rather than the intermediate (Aurantiac a) and dwarf (Nana) forms. A hierarchical analysis of molecular varian ce (AMOVA) was used to quantify and partition levels of variability in to between-and within-form components. This revealed that for the inbr eeding dwarf and intermediate forms most variation was observed betwee n, rather than within, forms. In contrast, the outbreeding tall forms exhibited as much variation within as between forms. These observation s have important implications for the maintenance and collection of co conut germplasm. This study also provided insights into the genetic (a s opposed to phenotypic) relatedness of coconut accessions. Morphologi cally the Aurantiaca group of accessions are considered to be intermed iate between the tall and dwarf accessions. Estimation of genetic rela tedness based on AFLP analysis identified the Aurantiaca group as bein g more similar to the dwarf rather than the tall group. In addition, p utative duplicate accessions were identified in the Aurantiaca group. Information emerging from this study will facilitate the management of coconut germplasm and optimise the choice of genetically divergent pa rents for crossing.