abstract potato virus a (pva) is one of the members of genus potyvirus. pva particles are straight to slightly flexuous rods and contain of single stranded rna. in the spring and summer of 2005, sampling accomplished to determine potato virus a from potato fields in northern and razavi khorasan provinces. samples with mosaic, shining and rolling of leaves carried in ice chamber to laboratory fo...

abstract the pvyntn strain induces potato tuber necrotic ringspot disease ptnrd . pvyntn strain is sub group of tobacco necrosis veinal pvyn strain . pvyntn strain is a recombinant between pvyn and pvyo strains . symptoms are often totally symptomless or undetectable by visual inspections at harvest , usually are apparent during post harvest in storage conditions and induce to decrease quality ...

tomato ringspot virus (torsv) is a member of the genus nepovirus, family secoviridae, causing substantial economically declining in perennial crops, including stone fruits, worldwide. during the years 2008 and 2009 a total number of 414 symptomatic and asymptomatic leaf samples were randomly collected from different stone fruit trees including peach, apricot, plum and sour cherry from fars and ...

carnation (dianthus caryophyllus) can be infected by several viruses that some are specific to carnation flowers. vegetative propagation of carnation, can easily disperse viruses by infectied cuttings. during the year 2007, viral-like symptoms were observed on carnation in mahallat greenhouses. 142 suspected samples from glass houses, with symptoms of reddish- purple flecks and spots on leaves,...

abstract during the winter and spring of 2007 and 2008, 450 samples (leaves of carnation plants) showing symptoms of yellowing, mottling, leaf malformation, and stunting were collected from greenhouses in mashhad and chenaran regions. the samples were tested by das-elisa for the presence of carmv. total rna was extracted by rnxtm (-plus) solution from positive infected samples confirmed in das-...