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  • Some thoughts on seemingly FMV-free plants

    I asked an acquaintance I made with a CRFG member several years ago about the prospects of cleaning up FMV from a variety for me. We had previously talked about his career in tissue culture both for a company and in his own business from which he had retired. I told him that there had been some talk that fig plants from Agri-Starts were free of FMV. I will take just portions of his comments here due to the personal nature of the comments that are not important to this information being shared. My point in posting this is to possibly help explain why we sometimes see some sources of figs that seem to be healthier than the original source. Sometimes there are claims of something being "FMV free". Personally, I think that is very unlikely.

    "On the web, I looked over Agri-Starts list of Ficus carica from tc and its home page but I could not find any claims of virus-tested, virus-free plants for figs. Tissue culture/Micropropagation methods rarely result in virus-free plants because of the nature of removing large pieces of plant organs (e.g. shoot tips)."

    "I have successfully done virus-freeing of tomatoes and cassava at my previous employment, 20 years ago, by culturing apical meristems combined with proprietary therapies for yielding virus-free plants."

    "Sometimes micropropagated plants (figs?) are healthier than conventionally propagated plants because the plants have been freed of a systemic load of microbes (bacteria, fungi) through tissue culture. Sometimes, the virus titer is low to begin with and kept low or latent because conditions are not ripe for symptoms to appear."

    My friend went on to say that for him to help me would require a lot of research and that there would be a steep learning curve and it would mean he would need to come out of retirement. Can't say I blame him.
    My fig photos <> My fig cuttings (starts late January) <> My Youtube Videos

  • #2

    Thanks for sharing your thoughts and findings on FMV...

    Agristart only mentions indexing for virus with their Petite Negri cultivar, https://www.agristarts.com/index.cfm...D/45/index.htm . But there's been successful virus eradication of tissue cultured fig trees, https://www.researchgate.net/publica...ree_fig_stocks , and as stated only 1 specific virus has proven to be persistent.

    From all the available information and observations I would agree that some cloned plants can and may be healthier than their parents simply due to cultural practice and location. It would be interesting to commission a lab like Agristart to tissue culture a particularly sought after cultivar since there is only a minimum set up fee and minimum wholesale order requirement.
    Last edited by AscPete; 04-03-2016, 05:44 PM. Reason: fixed broken links
    Pete R - Hudson Valley, NY - zone 5b


    • #3
      Thanks, Pete. I am sure it is possible but don't know that it's viable/feasible. Foundation Plant Services located at UCD (a independent institution primarily serving the commercial tree and vine nursery) has told me they would attempt to do so at a cost of $2,000 per accession but that it is difficult and that a previous attempt was unsuccessful.

      Howard at USDA Davis told me a couple of years ago that Duarte Nursery tested the germplasm at Wolfskill and identified 7 strains of FMV. I speculate that Ischia Black may have all 7 strains, LOL.
      My fig photos <> My fig cuttings (starts late January) <> My Youtube Videos


      • #4
        Ohh man, that is a pretty expensive endeavor to go into especially knowing that the previous attempt was unsuccessful. I'm really interested in the Black Ischia myself and have watched your threads closely whenever you have posted about the variety. I was hoping you may have received more encouraging news but this does not appear to be the case. Darn this FMV! It's really quite a peculiar thing how this virus is able to affect some varieties so much more than others, but on top of that you are saying even within the severely affected varieties that the virus exists in different loads in different organs of the plant? Am I understanding that correctly? I'm no scientist or biologist by far, but I do find this topic very interesting and would like to gain a better understanding of it. Thank you for sharing your knowledge on the topic Harvey and also thank you Pete for adding to the topic as well. I look forward to reading more about this in this future
        My Plant Inventory: https://docs.google.com/spreadsheets...HZcBjcsxMwQ7iY

        Cuttings Available 2022:


        • HarveyC
          HarveyC commented
          Editing a comment
          I cannot really say for sure if the level of infection varies in different &quot;organs&quot; of a plant but some plants which seem to grow more vigorously (for reasons that are not clear), they seem to show the symptoms less and might have a lower level of infection.

          I believe that plants may also fight infections with different degrees of success.

          Farming is usually a fairly high risk venture and I've done more foolish things than this, but still just thinking about it.

      • #5
        Do you guys think that the heat treatment method has no real hope? Certainly would be nice if a "free" method like that could help.
        Greg, Maine, zone 5. Wish List: Green Michurinska


        • AscPete
          AscPete commented
          Editing a comment
          Heat treatment has been proven to work...

          Selective propagation of healthier stock has been recommended by UC Davis and has been proven successful to growing healthier clones by several forum members.

      • #6
        Cultural practices do make a big difference in at least outward signs of FMV. I know on my CCDG the plant looks completely healthy and shows no signs of the disease but if I take cuttings of it the cuttings and young rooted plants do show it till they grow out a bit.
        Cutting sales at willsfigs.com will continue till about March 1.


        • #7
          Nick in PA had previously written how his Black Madeira from Keith (KK) seem to grow more vigorously and may have said that they don't show FMD symptoms. I have heard from a friend in the UK recently who reported that the Black Madeira he's growing from my cuttings is doing much better than the cuttings he bought from Keith. Several of the plants I've started from my cuttings appear the same while others not. Don't know why but it makes it more of an adventure.
          My fig photos <> My fig cuttings (starts late January) <> My Youtube Videos


          • #8
            According to the wiki on FMV, the virus is able to move from cell to cell using a movement protein (MP). If this is correct, it makes FMV even harder to deal with as it continually stays inside the plant cell. I was hoping that maybe one could come up with a rinse/soaking treatment that one could place short cuttings into to eradicate the virus, but if FMV protects itself by moving from cell to cell without being readily accessible outside of the cell, I would think eradication through absorption would be pretty hard.
            Last edited by smithmal; 04-04-2016, 10:50 PM.
            Malcolm - Carroll County, MD (zone 6b). Interested in cold hardy figs. Currently container growing, MBVS, St. Rita, Olympian, RdB, Beale, Sal's EL, UCD 184-15s and Desert King.