Abstract:
Molecular markers have been used extensively in studying genetic diversity, genetic relationships and
germplasm management. However, the understanding of between and within population genetic
variation and how it is partitioned on the basis of geographic origin is crucial as this helps to improve
sampling efficiency. The objective of this study was therefore to assess the intra-specific diversity in
Oryza longistaminata and how the variation is partitioned within and between different geographic
locations, using molecular markers. AFLP analysis generated 176 bands that revealed high levels of
polymorphism (95.6%) and diversity within and between populations. The mean Nei’s genetic diversity
for all the 176 loci in the 48 populations was 0.302 and diversity for populations within countries ranged
from 0.1161 to 0.2126. Partitioning of between and within population diversity revealed that the mean
allelic diversity at each polymorphic locus was HT = 0.3445. The within population diversity was (HS =
0.1755) and the between population diversity was (DST = 0.1688). Results of AMOVA revealed
significant differences (p<0.05) in genetic variation among populations within different countries of the
region. Genetic parameters estimated from AFLP data indicated that there are high levels of genetic
diversity in the wild populations of O. longistaminata studied and that this diversity is higher within
than between populations. Hierarchical partitioning also revealed that most of this diversity is found
between populations within countries than among countries. Regional collection and conservation
strategies therefore need to consider country differences while national strategies should consider
population differences within countries.