Dinum Herath That is a good question. It is hard. But, at least you can try to add more medium into the containers and wait it out, because basically you cannot do anything during long lockdown for novel coronavirus crisis.

Dear Dinum Herath it has bad solution, as Yuan-Yeu Yau say. Even in the case that you add an extra of culture medium, it's a transient solution. You could also try reducing temperature a couple of grades; however, it can affect some species, besides it's also a temporal solution. An alternative to Yuan-Yeu Yau proposition is to inoculate few explants per container.

They have nutrients and moisture from the gel (assuming they're in gel), and they'll do OK without light for a while. You could maybe put them under lights or in a window but I'm not sure about that, it might be better to just leave them as is.

Like the others, Im thinking all you can really do is make sure there is enough of your culture medium but reducing the number of ex-plants in each medium as Ricardo suggested could reduce the nutrient requirements dependence on each gel which should hopefully give more time for survival in anticipation of things resuming. Its better to try in any case than simply let them die. In any case, having close to a light source should be considered.

Godwill Mih Chewachong Md. Harun-Or-Rashid Ricardo Julian Licea-Moreno Yuan-Yeu Yau for your support. As Ricardo Julian Licea-Moreno mentioned I guess reducing temperature might be a good option. when I looked at more details on temperature reductions it has a positive effect on maintaining culture. probably I will go with 18oC.

In addition to what has been said, if you can get culture tubes, a bit more media and individual plants per tube could help. Depending on your objective and the plant species you can remove or reduce plant growth regulators to arrest division. If you remove or reduce cytokinin they may not divided and finish the media or fill the containers.

Dear Dinum Herath,

You could keep them for several months at low temperatures in a range of 6 to 10-degree centigrade depends on species.

T.C. plants are in cantrol condition either in greenHouse or in lab where nutrient,humidity,light provided artificialy also maintain hygienic condition so no problem in outside conditions.🙏

I recommend others answers as well as suggesting slow growth media formulation by reducing the concentration of PGRs and reduction in temperature and explant number per culture vessel.

Actually, I am not a botanist to tell in this issue, rather I used to preserve animal tissues for long in LN2, keeping in mind that adding a cryoprotective agent such as DMSO or GLYCEROL at levels up to 10% of culture media, which maintain the cells in proper conditions for a long time. Hope to find out optimum solution for your experiment during this tough time.

It very much depends onWHICH shoots maybe or rooted plantlet you have to abandon.

Some shoots just cant be longer kept in tubes than 1 month. Maybe because if the hormones you have had to add. Then they NEED fresh medium.

Thus its good to have afvanced already to.all kinds of tissue cultures: that is stronger shoots or even rooted shoots. Those can stay alive much longer is the same tube without needing to be.handled.

And besides of that: I always close the tubes with parafilm in order not to get the least evaporation. Dont worry: they wont sufficate! If they are green. They make their own oxygen at night.

Thanks for S. Wenkart Moustafa Zeitoun . however, the lockdown period is more than 1 month now. so hard to maintain without subculturing.

You see: I am in the same boat. Something like that I did not experience neither.

Still dont know, when they allow to get back to the lab...

So far my experience goes, reduce the temperature of the culture room max 5 deg cel from the recommended unit. However, adding little bit more media and culture less number of Explants per Culture bottle or test tube are also conducive in minimizing In Vitro growth.

Dear Dinum Herath, I recommend the low temperature can be helpful for growing long term in vitro plants without subculturing.

But you had been looking for an answer as how to get the cultures in the tubes thru the Corona. Now we still did not finish with it. That is: you could have someone to go to your growthrooms and lower the temperature there. But you cant do anything about the amount if medium inside the tubes. At least I cant. As I cant prepare medium just now.

Go to work depends of locals regulations. Here in Spain is allowed to go to lab if the distancing regulations are maintained. I was remembering another solution, if you can go to work. Some years ago was proposed 2 layer culturing. It's an easy, fast and secure way to mantain for long time (with limitations, of course) plant stocks. Check:

De Riek, J., Piqueras, A., & Debergh, P. C. (1997). Sucrose uptake and metabolism in a double layer system for micropropagation ofRosa multiflora. Plant Cell, Tissue and Organ Culture, 47(3), 269-278.

Our gene pole collection is kept at low temperature (8C) with light this way it require very little maintenance. We are allowed to send a person to the lab to do the require maintenance.

Thanks Ricardo for the 2-layer. I shall read it soon

S. Wenkart you're welcome. That's this site was made for.

Thanks Ricardo Julian Licea-Moreno and S. Wenkart

Dear Yaser, what Bonzi is?

Thanks

I guess Ricardo Julian Licea-Moreno has given a good suggestion to keep in vitro regenerated plants survive for longer period of time during this pandemic.

Dear S. Wenkart and all those interested people, I made a mistake, I have sent the wrong paper regarding 2F. Now I sending the right title where it was presented for the first time.

Maene & Debergh 1985 Liquid medium additions to established tissue cultures to improve elongation and rooting in vivo

Hello Dinum Herath, from my end i will suggest you to go for encapsulation of callus in sodium alginate beads to preserve your calli for longer duration because due to this pandemic situation, this is the only technique that you can do to and place those beads in -20 so that you can work and regenerate when ever it is possible for you to do on MS medium without entering to lab. Once the situation is ok, then you can retrieve by placing those callus encapsulated beads on MS medium for their ggrowth.

All the best for your study.

We slow down the growth by CCC.

Dear Dinum Herath,

Reduced-temperature storage is an interesting method that has been implemented by genebanks to prolong the time intervals between tissue culture transfers; it could be an interesting option during the lockdown period. I am sharing a paper.

Best regards,

Jean

I have the same opinion as Dr. Jean. Yes, by reducing temperature of the Culture room we may slowdown the In Vitro growth. I addition lowering the amount of Sucrose in the media could be a better option. Also omission of CYTOKINES would be an effective way.

The best method to keep tissue culture plants survive in lock down period to keep them at lower temperatures and low intensity of light.

How did your explants do during and after lockdown? What did you end up doing? Any major explant losses or contamination issues? If you could share your experience that could be helpful for someone in a similar situation (hopefully we won't have another lockdown but you never know)

Plants would require attention for subculture and acclimatization.... It's similar to asking what can one do to the newborn babies in a hospital green incubation in the lockdowns. The best thing is to ask for approving (your entry) to the management, explaining them the criticality. No body can care the plants than you can.. as also for the babies..

Overall, carbon sources concentration, light (presents, type and quality), mineral nutrition, permeability or fluidity of media, temperature, genotype, season, gas exchange, pH and specially plant growth regulator have a vital role in growth of in vitro plantlet. As a result, plant growth can be limited by minimizing plant growth conditions. My recommendation is to use a larger amount of culture medium (50 cc instead of 25 cc), reduce the temperature of growth chamber(3-4 C) and halve the light intensity. Due to technical problems in our laboratory, I kept my samples with this method for 5 months.

Hoping for an end to this pandemic

With luck