Rob,I would find it interesting to be able to evaluate the species of Hostas in their natural habitat and see if HVX exists at all there. It is quite posssible the virus is there but the species have a natural immunity and are resistant. I am not sure what we hobbyists refer to as species hostas, such as our plantaginea, or ventricosa, are genetically identical to the native hostas. They have been propogated quite often out of their native environment. I don't recall anyone showing a picture of a species hosta with HVX in this forum though.

Tissue Culturing may be creating varieties that don't have the same inherent immune systems as their founding species.

This is, of coourse, speculation; but it would be consistant with history where other heavily forced divergent speciation has occured in other living things creating weaker offspring.

I am sure someone has been looking into just what you question and could give some input. I hope they get wind of your post and choose to comment.

Les

It had to be a mutation. Either a mutation of another Potex virus that didn't previously effect Hostas or of a virion that was present in Hostas but didn't show itself. Most likely it was the former, especially if the same large machines that were used to harvest other plants were used on Hostas. What is interesting about viruses is their ability to literally reinvent themselves in different forms. Viruses can actually perform genetic engineering.

Steve

Didn't the first known HVX come out of the big farms in Holland? If so, then what Steve says makes sense.

bkay

I agree with Steve, it is likely a mutation of a potexvirus (from POtato virus) / mosaic virus. My guess is that it is mutated from Tobacco Rattle virus as this study (linked) shows tobacco plants can also be infected. It also verifies that it can only be transfered mechanically by fluids.

Here is a link that might be useful: Infection of tobacco plant with HVX

Most probably initially spread by those silly wooden clogs the Dutch wear.

"It also verifies that it can only be transfered mechanically by fluids."

By "It" I meant HVX.

Robs question could refer back to origin: and a mutation of an original virus is not disqualified. The mutation of a latent virus that a species may have beaen imune to may have been made possible by the manner in which we (peeps in general) have found to mutate the species into what we feel are more desireable hostas through selective propagation.

It is really a moot point, seing as both could be true.

Les

Les,

I would not disregard the fact that the Tobacco Rattle Virus is a Potexvirus and it seems to me more than coincidence that HVX can be transmitted to a tobacco plant and hostas.

I don't find you suggestion that HVX could somehow be an "original" virus as plausible. It is a novel approach that goes against any theory of viruses and their propagation and mutation I have ever seen.

Please share your basis for assuming that virus just appeared as an original. I am no expert, but your thought that there are latent viruses that only exist in hostas and can only be transmitted through fluids and cannot live without hosta or tobacco plant tissue, have somehow been lying in wait for "peeps", aka people, to hybridize a host hosta that accepts this stealth virus, surviving, who knows how until then, and then infects hostas now susceptible to it and then develops the trait that it cannot live outside living hosta tissue or this tobacco plant and immediately also mutates to the HVX virus that seems to be able to infect most if not all hostas.

You reject offhand that a virus that exists only in a tobacco plant and in hostas, that is a potexvirus as TRV and HVX both are, could have simply been a mutation of TRV when viroligists say this is how new viruses are generated. You reject hundreds of years of study and introduce your invented and scientifically impossible theory as a rebuttal to a perfectly possible and logical theory of viral mutation.

WOW,

Jon

Jon - I don't understand your problem. I haven't "rejected" anything, and I didn't say the HVX virus existed back in the orient long before we knew about it. You keep putting YOUR words in my mouth.

I suggested HVX could be a mutated form of a virus that has existed for years even back to the native lands of the hosta species. Thats not such a far reach, in my OPINION. If I recall, Rob asked what came first, the chicken or the egg. That question presumes going way back to the origon of a species, either virus or hosta since it asked "What Came FIRST"

All I have done is open a perspective, not offered an answer.

You're a riot Jon.

Les

Exact words-

"The mutation of a latent virus that a species may have beaen imune to may have been made possible by the manner in which we (peeps in general) have found to mutate the species"

You have suggested first there was a latant virus-

Latant virus: A nonactive virus which is in a dormant state within a cell.

Then you suggest that a hosta was hybridized that somehow awoke this latent virus.

This is impossible. Viruses mutate, they do not sit and wait centuries for appropriate hosts to be hybridized / mutated to awaken them. You keep saying the impossible is possible.

I have suggested that the tobacco rattle virus which is viable in Hostas and Tobacco plants may have mutated into HVX. As possible evidence of this I offer the fact that HVX can only exist in the live tissue of hostas and tobacco plants.

I am not saying that HVX mutated fron TRV, but there is a definite significant connection and a serious person would see that the fact that these two plants, both have the ability to be infected with HVX could be either a huge coincidence or there may be some connection between TRV and HVX.

You have given an explanation that disagrees with hundreds of years of virology and defend it by saying anything is possible. Les, not everything you imagine is possible and the scenario of dormant viruses being awakened by hybrid hostas is true fantasy.

You, in previous posts have said that HVX could possibly lie dormant, because anything is possible. Tens of thousands of dollars have been spent and the world's best plant virologists say it doesn't, but your arguement is anything is possible. Well Les, pigs don't fly and neither does your theory.

Experts will tell you it is believed that HVX originated in native colonies, especially as it is so specific to the genus Hosta. There are two known strains, and some publications refer to a Japanese strain and a Korean strain. Some of the earliest examples of HVX infected plants are of Japanese origin, likely collected in native colonies where the virus would have been isolated until humans intervened, thought they were sports, and then started to propagate and sell them. Eventually people started to collect them, but things didn't really get out of hand until HVX entered the Dutch wholesale supply. Their processes of field growing and power washing for export caused the rapid spread of HVX into cheap plants for mass marketing, and since it is now in their fields they won't likely ever get rid of it until they stop growing hostas there. Even certified HVX free stock is getting infected out in the fields where previously infected plants were removed, or they are infected during the export process.

"Experts will tell you it is believed that HVX originated in native colonies, especially as it is so specific to the genus Hosta."

It is not specific to hostas. It is specific to hostas and a tobacco plant. HVX and Tobacco Rattlesnake Virus are both Mosaic viruses. Could it have originated in China, Japan, Korea yes. Could it have mutated in Holland, yes. Could it have mutated in any of these countries from TRV, yes.

Could it have been a dormant virus waiting for a hybrid hosta to become activated and when activate show no sign of being capable of going dormant as some other viruses do, no.

The connection to tobacco plants and the connection to TRV and HVX as mosaic viruses makes me question wether HVX is a mutant TRV virus. It is just my hunch and I have given my reasons for it.

Jon

Chris,

Thanks for the history lesson. Is it true that the Dutch are allowed to have 5% or less virused plants to be exported to the US and other countries. It was Carol Brashear who mentioned this at a presentation to the NEHS. It's hard to believe the USDA would allow this.

Steve

I didn't say it was entirely specific. Tobacco Rattle Virus is an entirely different virus altogether and not remotely related. TRV is a tobravirus and HVX is a potexvirus. There is no evidence of any mutations or any more than two strains. We are talking about a virus that likely has been around as long as hostas have been on the planet, and it only showed up in gardens because people did not recognize viral symptoms and thought they were sports, so they started to name, collect, and sell these infected plants as if they were new cultivars.

Yes, the Dutch convinced the USDA to allow 5% of the imports to be infected, and a lot of it is based on visual inspections in the field, so it is often much higher than this. Ornamentals are not as high on the list of priorities for the USDA as with other crops.

Potexvirus and Tobravirus are filamentateous RNA viruses with a single coat protein protecting a single strand helical array.

Saying they are not remotely related is an overstatement. Saying there are only 2 strains is a misunderstanding as there are many strains of Potexvirus and also of Tobravirus. Saying it is a virus that most likely has been around as long as hostas have been on the planet, discounting the known ability and history of viral mutation, seems to be far-fetched and improbable.

My GUESS may be completely wrong. I have always stated it as a guess. I don't mind correction. I don't mind other's theories. I do mind condescending rejection with theories that have less validity than my guess.

Jon

Sorry, I meant 2 strains of HVX, and sorry for coming across as condescending.