Dasheen Mossaic virus of Aroids

From: Denis denis at skg.com> on 2000.07.14 at 23:01:43(5114) Dear Aroiders: I inadvertantly opened a can of worms and now I am endeavoring to put the slimey little devils back in the can and tape the lid in place with duct tape. I hope this short letter helps with the virus thing. The following material is excerpted from Dr. Ann Chase's book, "A Compendium of Ornamental Plant Diseases." Bear in mind that she is writing about Commercial Aroid Foliage Crops and does have much to say about the effects of DMV on other non-commercial Aroids such as the ones Aroid-L Subscribers like to grow. "Dasheen Mossaic Virus (DMV) causes the single most important Virus disease of Foliage Plants. The Disease was first described by Zettler et al in 1970 and has since been reported in many members of the Araceae Family including food crops and Ornamentals?. Symptoms vary from one host to another. They are not always apparent on infected foliage plants or present on all their leaves. Young seedlings of Philodendron selloum develope systemic vein chlorosis, and severe distortion and the Mossaic symptom occur on most plants. In contrast Caladium hortulanum Birdsey (fancy leaved Caladiums) Colocasia esculenta (L.) Schott (Dasheen or Taro) and Xanthosoma sagittafolium (L.) Schott (Cocoyam) Develop a feathery mossaic pattern, but many of their leaves are asymptomatic? The most commonly infected foliage plants are Dieffenbachia spp. and Aglaonema spp. Ring spot, mossaic patterns and leaf distortions usually occur on infected Dieffenbachias?DMV is transmitted by Aphids in a nonpersistent manner or mechanically in the sap from infected plants (non-sterile cutting or harvesting tools)?. The host range of DMV has been extensively examined. The only plants infected appear to be members of the Araceae Family. Reported hosts are Aglaonema, Alocasia, Amorphophallus Anthurium, Arisaema, Caladium, Colocasia, Cryptocoryne, Dieffenbachia, Philodendron, Richardia, Spathiphyllum, Xanthosoma, and Zantedeschia?. DMV infections of foliage plants are systemic, and no chemicals are available for the control of Virus Diseases?. Research done has shown that fresh corm weights of Caladiums infected with DMV were reduced by 40% and the leaf area was reduced by 53% over uninfected controls. " +More >From my own experience I know that the Symptoms of DMV may not be expressed when all the environmental factors are optimized. But, when stress in put on an infected plant such as too much light or shade, too much heat or cold, too much or not enough water in the root zone or the presence of a bacterial or fungal pathogen, that's when the plant falls apart or in the case of Caladiums, the corms get smaller and smaller. The tissue culture of virus free commercial foliage plants is bringing DMV under control in the industry. However, our favorite collectable lovelies are not always candidates for the expense of isolating a tiny microscopic piece of virus free tissue that we subsequently propagate in vitro under aseptic conditions until we produce a crop of virus free little lovelies. Don't live in fear of DMV just be aware that it exists, keep the aphids out, and take care not to cut up your valuable collected plants without disinfecting the blades between plants. Paul Tyerman wrote: > > Howdy All, > > I remember reading somewhere that virus cannot penetrate within the first > 12 (or some such) layers of cells around the meristematic growth point, > therefore if tissue sulture is achieved on the meristematic growth it > should be virus free..... > > Can't remember where I read it. > > Paul Tyerman > (Canberra, Australia) > > > > >Dear Denis, > > > >See my other postings from this AM with my opinions on this virus thing. > > > >One other point---since most or all of the commercial Caladium vars. in > >cultivation are produced from tubers that were created YEARS ago by crossing > >different species and varieties, if we were to produce seed from these > >present day ones the chances of obtaining anything worthwhile are slim to > >none, most of them just have too many parents!! > >I thought that a strain of Aroid could be 'cleansed' of this virus by > >'doing' it in tissue culture, which eliminated the virus? Read it > >somewhere. > > > >Cheers, > > > >Julius > >

From: StellrJ at aol.com on 2000.07.15 at 16:23:19(5124) In a message dated 7/14/00 7:07:00 PM Eastern Daylight Time, denis@skg.com writes: << "Dasheen Mossaic Virus (DMV) causes the single most important Virus +More disease of Foliage Plants. The Disease was first described by Zettler et al in 1970 and has since been reported in many members of the Araceae Family including food crops and Ornamentals?? >> I'm trying to remember...is this the virus I have heard of, whose vector is a beetle named Papuana? Jason Hernandez Naturalist-at-Large

Note: this is a very old post, so no reply function is available.