Abstract:
The use of molecular markers for the detection of DNA polymorphism is one of the most
significant developments in the field of molecular biology. In this study, three types of
molecular markers: RAPD, ISSR, and SSR (microsatellites) were used to determine the genetic
relatedness among the eleven barley cultivars grown in Palestine. These cultivars includes:
Baladi, Nabawi, Rihane, ICARDA 6, 16, 20, 27, 29, 30, 33, and 34. Five primers of each
molecular marker were used. Amplification products of the three methods represent 102 loci of
the barley genome in addition to the wheat out group. Ninety three out of the total loci were
polymorphic, which correspond to 91%. Moreover, 22 exclusive markers (loci) were identified
for several barley cultivars of which 8 markers belong to the wheat out group. Such private loci
could be used for cultivar identification. In general, an average of 59.4 loci per cultivar was
recorded.
The phylogenetic trees show that RAPD and SSR markers are highly polymorphic. Less
polymorphism was revealed by the ISSR method. The polymorphism obtained by the three
methods was sumed up and used to establish a phylogenetic tree for the eleven barley cultivars.
UPGMA trees show two major clusters. The first one encompasses cultivars Rihane and
ICARDA16, whereas the second cluster is further subdivided into two subclusters. The first
subcluster contains cultivars ICARDA 6, 27, 33, 30, 20 and Baladi while the second subcluster
is included of ICARDA29, 34 and Nabawi cultivars. The tree also shows that cultivars Baladi
and ICARDA 33 are very closely related. Similar clustering patterns were obtained by the
Principal Coordinate Analysis (PCA) which supports the accuracy of the phylogenic tree.
The results of this study indicate the presence of high genetic diversity among the tested barley
cultivars which makes them of a special value pertaining to any breeding program aiming at
increasing their productivity and the development of tolerance to biotic and abiotic stresses. To
the best of our knowledge, this is the first such study for the barley (Hordeum vulgare L)
grown in Palestine.
