Abstract:
The genetic variability and relationships among 14 date palm (Phoenix dactylifera L.)
accessions representing six Egyptian cultivars were assayed using 27 RAPD and 10 ISSR primers.
The level of polymorphism among the 14 accessions as revealed by RAPD and ISSR was 25.2% and
28.6%, respectively. These low levels of polymorphism reflect the narrow genetic background of
these accessions. The genetic relationships among the 14 accessions were estimated in terms of
similarity using Dice coefficients. The genetic similarity ranged from 96.1% to 99.5% and from
91.2% to 100% for RAPD and ISSR, respectively. The inter-cultivar relationships among the six
date palm cultivars based on RAPD and ISSR revealed the highest genetic similarity between the
cultivar Bertmoda and each of the cultivars Malkaby and Sakkoty. The RAPD and ISSR based
dendrograms clustered the accessions belonging to each of the 3 cultivars Fraihy, Siwi and Gandila
in separate groups. However, the reshuffling in the position of some of the accessions belonging to
the other cultivars in the different dendrograms revealed that they share common gnenetic
background. Cultivar-specific DNA markers characterized different genotypes and therefore, were
used to generate unique fingerprint for each genotype. The RAPD and ISSR revealed 17 and 5
cultivar unique DNA markers, characterizing 4 and 5 cultivars, respectively. Moreover, each of the
RAPD and ISSR was successful in identifying accession-specific markers characterizing five
accessions.
