Abstract:
To study molecular evolutionary
characteristics a
nd genetics of
beet necrotic yellow vein
virus
(BNYVV) isolates population from Iran
, nucleotide sequences of p25 and coat
protein (CP) were determined and the amino acids sequences thus deduced were analyzed
using phylogenetic and population genetics
methods. A survey of BNYVV in Iran
indicated the infection of 288 collected sample
s out of 392 samples in most beet growing
areas and that most of the isolates (92%) were of the
A
-type and the rest of isolates (8%)
were
P
-type. Our molecular evolutionary analysis showed that CP was highly conserved
but allowed to assign all isolates to three distinct groups. Different parts of p25 coding
regions were under different evolutionary constraints. The most positive selection was
detected at the position 68, the second amino
acid of the tetrad motif. Iranian isolates
were found to cluster with European isolates
into three distinct clusters based on p25
sequences. Population genetics analysis rev
ealed that BNYVV populations have low
differentiation (Kt= 3.97145) and low diversity (
π
T= 0.006, Hd= 0.860) wi
th frequent gene
flow indicating lack of phylogeogr
aphic structure between populations.
Keywords
: Evolution, Phylogenetic analysis, Plant virus, Positive selection.
