Characterization and diversity assessment in coconut collections of Pacific Ocean Islands and Nicobar Islands
Characterization and genetic diversity assessment among 30 conserved coconut accessions collected from Pacific Ocean Islands and Nicobar Islands for morphological traits, physico-chemical traits of tender nut water, leaf biochemical parameters and molecular characterization by using random amplified polymorphic DNA (RAPD) markers were undertaken at World Coconut Germplasm Centre, Andaman. Significant variations were observed for most morphological and nut component traits. Out of the 30 accessions characterized, four accessions, namely, Niu Leka, Hari Papua, Niu Oma and Nikkore were dwarfs among which Niu Leka was identified as a unique dwarf with higher copra content. A dendrogram of genetic relationship obtained through RAPD markers showed distinct variation with 66% in all accessions. The average polymorphic information content (PIC) value of 13 selected primers was 0.29 and maximum and minimum PIC values was 0.46 and 0.17 for primers OPF-19 and OPH-25, respectively. Cluster analysis by UPGMA method grouped the accessions into two major clusters. The results will be useful in the selection among these conserved accessions for specific traits for future utilization in crop improvement initiatives based on their performance for different desirable traits and the level of diversity.
Key words: Coconut, genetic diversity, characterization, RAPD, cluster analysis.