TITLE:
Molecular Study of a New Disease of Peach in Iran Associated with a Phytoplasma
AUTHORS:
Maryam Ghayeb Zamharir
KEYWORDS:
Peach; “Candidatus Phytoplasma Phoenicium”; Kurdistan; Iran
JOURNAL NAME:
Advances in Microbiology,
Vol.4 No.1,
January
16,
2014
ABSTRACT: In recent years, a disease has been reported to affect
peach trees in Kurdistan province of Iran causing serious losses to the
production. Main symptoms of disease include leaf stunting and yellowing, which
lead to failure in fruit production at harvest. For diagnosis of disease and
identification of the causal agent, symptomatic leaf samples were collected in
Kurdistan orchards during summer 2010 and were carried to the laboratory. Total
DNA was extracted from plant samples according to the standard procedures and indexed
by grafting and nested PCR using phytoplasma generic primers, P1/P7 and
R16F2n/R2. PCR products were characterized by RFLP technique and direct
sequencing. The 16S rDNA sequences were compared with those of other phytoplasmas
in GenBank. Phytoplasma rDNA was amplified from 20 out 35 samples. The 16S rDNA
sequences of the phytoplasma were identified in Peach samples which showed 98%
similarity to that of “Candidatus Phytoplasma phoenicium” which
is considered to be the causal agent of Almond witches’ broom. Phylogenetic
analysis of 16S rDNA sequences placed peach strains in Almond witches broom
isolate as a member of pigeon pea witches broom (PPWB) group. Further studies
on the epidemiology of “Ca. Phytoplasma
phoenicium” and its vector(s) in Iran are recommended in order to identify new
natural hosts and develop successful disease management programs.