Is CYDV Cereal yellow dwarf virus? Are we talking about nucleotide identity? I'm not sure what CtRLV is, but the definition of species for luteoviruses is greater than 10% aa differences. You'll need a lot more of the genome, like the coat protein, to determine if it is a different virus.

Hi, first of all I think you should write what virus is: CMD, CtRLV, CYDV, CmoV and CtRLVa. It's a lot easier for all readers. Not everybody is familiar with this abbrevations. Cheers, Nadine

I agree with Nadine. Virologists are typically aware of nomenclature on their own research fields but generally lost when we talk about a different virus or topic.

It's a pity that Muhammad isn't interested in getting some more response...

CMD is Carrot Motely Dwarf complex (the resulting disease from Carrot red leaf virus transencapsidating Carrot mottle virus and/or Carrot red leaf associated viral RNA).

In this case CYDV will be Cereal yellow dwarf, a member of the luteoviridae along with Carrot red leaf virus, so as the first responder mentions, with a demarcation of 10% aa identity I would want far moe of the genome to make a call like that. Assuming you are playing with carrots or other umbellifers, it is likely to be Carrot red leaf virus.

Cheers, Adrian

Adrian Thanks for explaining , and sorry to all, I was away from internet last week.

CMD (Carrot Mottly Dwarf Complex that includes the CtRLV=Carrot red leaf virus(polerovirus), CMoV= Carrot mottle dwarf virus (umbravirus) and CtRLVaRNA= Carrot red leaf associated RNA virus(unassigned)].

I was wonder how monocot plant (cereal) virus could be detected in dicot plant (carrot) or have identity in most conserve region i.e RdRp gene. Even they have different aphid vector. And Aphid vectors have too much specificity for viruses.

I am interested to know how you detected the virus presence in the sample.

There are some reliable conventional PCR primer sets for CMD, Vercruysse et al (2000) (ref included below and we have been developing real-time PCR for these virsues (Manuscript currently in review).

These may help as a secondary diagnostic on the orginal sample material if you have used another method to isolate your gene fragment.

Additionally, if UK carrots are taken as a guide, there are possibly going to be several other viruses in the sample, so worth looking further than just the CMD complex.

regards,

Adrian

Vercruysse P, Gibbs M, Tirry L, Höfte M (2000) RT-PCR using redundant primers to detect the three viruses associated with carrot motley dwarf disease. Journal of Virological Methods 88: 153-161.

I used the same primers as reported in paper you mentioned. Then I got these results, The Genebank search result showed the maximum identities for

CtRLV (210bp) nucleotide with CYDV-RPV 91% CYDV-RPS 90% BYDV-PAV 89% (DQ988084, AF235168, AF020090);

aRNA (484bp) 75% with Carrot red leaf luteovirus associated RNA-a8 (AF020616);

MoV (408bp) 81% with Carrot mottle virus isolate-Weddel (FJ188473, FJ969848).

Then I designed the primers for realtime and performed RT-qPCR and analyse the melt curve differences.

Unfortunately I don't have access to the samples anymore, as I moved back to my country.