Background: The present study was undertaken towards the development of SSR markers and assessing genetic
relationships among 32 date palm (
Phoenix dactylifera
L.) representing common cultivars grown in different
geographical regions in Saudi Arabia.
Results: Ninety-three novel simple sequence repeat markers were developed and screened for their ability to
detect polymorphism in date palm. Around 71% of genomic SSRs were dinucleotide, 25% tri, 3% tetra and 1%
penta nucleotide motives. Twenty-two primers generated a total of 91 alleles with a mean of 4.14 alleles per
locus and 100% polymorphism percentage. A 0.595 average polymorphic information content and 0.662
primer discrimination power values were recorded. The expected and observed heterozygosities were 0.676
and 0.763 respectively. Pair-wise similarity values ranged from 0.06 to 0.89 and the overall cultivars averaged
0.41. The UPGMA cluster analysis recovered by principal coordinate analysis illustrated that cultivars tend to
group according to their class of maturity, region of cultivation, and fruit color. Analysis of molecular variations
(AMOVA) revealed that genetic variation among and within cultivars were 27% and 73%, respectively
according to geographical distribution of cultivars.
Conclusions: The developed microsatellite markers are additional values to date palm characterization tools that
can be used by researchers in population genetics, cultivar identification as well as genetic resource exploration
and management. The tested cultivars exhibited a significant amount of genetic diversity and could be suitable
for successful breeding program. Genomic sequences generated from this study are available at the National
Center for Biotechnology Information (NCBI), Sequence Read Archive (Accession numbers. LIBGSS_039019).
