S. Svitashev et al., PHYLOGENETIC ANALYSIS OF THE GENUS HORDEUM USING REPETITIVE DNA-SEQUENCES, Theoretical and Applied Genetics, 89(7-8), 1994, pp. 801-810
A set of six cloned barley (Hordeum vulgare) repetitive DNA sequences
was used for the analysis of phylogenetic relationships among 31 speci
es (46 taxa) of the genus Hordeum, using molecular hybridization techn
iques. In situ hybridization experiments showed dispersed organization
of the sequences over all chromosomes of H. vulgare and the wild barl
ey species H. bulbosum, H. marinum and H. murinum. Southern blot hybri
dization revealed different levels of polymorphism among barley specie
s and the RFLP data were used to generate a phylogenetic tree for the
genus Hordeum. Our data are in a good agreement with the classificatio
n system which suggests the division of the genus into four major grou
ps, containing the genomes I, X, Y, and H. However, our investigation
also supports previous molecular studies of barley species where the u
nique position of H. bulbosum has been pointed out. In our experiments
, H. bulbosum generally had hybridization patterns different from thos
e of H. vulgare, although both carry the I genome. Based on our result
s we present a hypothesis concerning the possible origin and phylogeny
of the polyploid barley species H. secalinum, H. depressum and the H.
brachyantherum complex.