جستجوی مقالات مرتبط با کلیدواژه "16srii" در نشریات گروه "گیاهپزشکی"

Alfalfa witches’ broom (AWB) is one of the most important alfalfa diseases in Iran. To characterize 16SrII group phytoplasmas associated with this disease, symptomatic and asymptomatic plants were collected during 2013-2015 and subjected to direct and nested polymerase chain reaction (PCR) using P1/P7, R16mF2/R16mR2 and R16F2n/R16R2. PCR amplicons of ~1.8, ~1.4 and ~1.25 kb respectively, were obtained only from all symptomatic plants. Restriction fragment length polymorphism (RFLP) analysis of R16F2n/R2 amplicons showed that the phytoplasma associated with AWB disease were members of 16SrII group subgroups 16SrII-D and -C. Blast analysis of these amplicon sequences and sequence homology of collected strains and strain sequences retrived from GenBank (AWB strains Chahgeer, Juyom and Bushehr) confirmed that AWB phytoplasmas collected from Bafg, Ardakan, Bahabad and Herat (Yazd province), Nikshahr (Sistan-Baluchestan), Bam, Zarand, Jiroft (Kerman province), Bushehr (Bushehr province), Tabas (South Khorasan province), Jowkar (Hamedan province) and Zardenjan (Esfahan province) cluster with phytoplasma strains enclosed in the 16SrII-D subgroup, while AWB strains from Chahgeer (Yazd province) and Juyom (Fars province) cluster with phytoplasma strains in the 16SrII-C subgroup. Based on these results the predominant strains of 16SrII phytoplasmas associated with AWB disease in Iran were classified in the 16SrII-D subgroup. In Ashkezar and Abarkouh in Yazd province entire alfalfa farm was infected with witches’ broom disease. In 3 year alfalfa stands in Ashkezar alfalfa farms were plowed due to high incidence of the disease.

In 2010- 2012 surveys, witches''- boom disease of tomato was observed in Borazjan area (Bushehr province, Iran). Agent of the disease was transmitted from tomato to tomato and eggplant by grafting and to Madagascar periwinkle via dodder inoculation, inducing phytoplasma-type symptoms in inoculated plants. Presence of phytoplasma in naturally affected tomatoes and all symptomatic graft and dodder inoculated plants was confirmed by direct and nested polymerase chain reaction (PCR) using primer pairs P1/P7 and R16F2n/R16R2. BLAST search and phylogenetic analysis of 16SrDNA showed that detected phytoplasma belonged to peanut witches''- broom (16SrII) group. Phylogenetic analysis, percent homology and virtual RFLP indicated that, as a member of 16SrII group, Borazjan tomato witches’- broom (BTWB) phytoplasma together with Bushehr eggplant and alfalfa witches’- broom (BEWB and BAWB, respectively) phytoplasmas were classified with Candidatus Phytoplasma australasia, a phytoplasma related to 16SrII-D subgroup. Based on the same analysis, BTWB, BEWB and BAWB phytoplasmas were differentiable from three other Iranian 16SrII related phytoplasmas associated with alfalfa witches''- broom diseases in Yazd and Fars provinces and lime witches''- broom disease in southern Iran.This is the first report of tomato witches''- broom disease and characterization of its associated phytoplasma in Iran.