Abstract:
Retrotransposons (RTNs) constitute informative mole
cular markers for plant species
because of their ability to integrate into a multit
ude of loci throughout the genome and
thereby generate insertional polymorphisms between
individuals. In the present study,
RTN-based molecular markers, IRAP (inter-retrotrans
poson amplified polymorphism)
and REMAP (retrotransposon-microsatellite amplified
polymorphism), were applied to
study RTN integration events and genetic diversity
in 100 melon genotypes (88 genotypes
from 11 populations, three inbred lines, and 9 hybr
ids). A total of 94 and 262 loci were
amplified using 5 IRAP and 15 REMAP primers, respec
tively. The percentage of
polymorphic loci (PPL) in populations ranged from 3
9%
(Zivari Shahrood) to 48%
(Shadegani E). The Mantel test between IRAP and REM
AP cophenetic matrices
evidenced no significant correlation (r= 0.29). IRA
P+REMAP-based cluster analysis using
UPGMA algorithm and Dice similarity coefficient dep
icted 6 groups among 100 melon
genotypes. AMOVA revealed the higher level of genet
ic variation within populations
(67%
) compared to among populations (33%
). The mean
Fst
values of all groups, except
for group VI, were more than 0.20, demonstrating di
fferentiation among the populations
and genetic structure of the studied melon collecti
on.
Keywords:
Cucumis melo
, Genetic variability,
Reme1
, Retrotransposon.
