Feeding in the flask!

[Stone]

So I got this flask of gigantifoliums. It was way over due for a de-flask (or preferably re-plate) evidenced by the fact that every seedling only had 2 good leaves left and 2 or 3 dead ones and no live root tips anywhere. They obviously ran out of nutrients long ago!

Anyway, rather than take them out as is, I decided to try to introduce some nutrients back in there before I disturbed them. It was a plastic whiskey bottle so I cut the top off and left them for one week. There was only very mild contamination of the agar. Then I gave them a hit of very week fertilizer with all nutrients. (swished around just enough solution to cover the roots and the base of the plant, let it sit for a few minutes then emptied) A week after that I gave them some IBA rooting hormone. There was little change in leaf colour but a week or so later that I noticed that most seedlings had a tiny new root emerging from their bases.
A successful kick start I think!
They are now in community pots and looking quite ok.

 

[naoki]

Nice save, you didn't take photos? I'm just curious, was it a vented or unvented flask?

 

[Ozpaph]

Very interesting. Agar on or off for the 'dosing'?

 

[JAB]

Nice! What is IBA?
Thanks for sharing your methods.

 

[PaphMadMan]

Did you use any fungicide after opening the flask?

...What is IBA? ...

IBA is indole-3-butyric acid, an auxin type plant hormone that promotes rooting, among other things. IAA, indole-3-acetic acid, is the most common naturally occurring form, but IBA is more stable for long term storage so it is commonly found in root promoting hormone products.

 

[naoki]

IBA is indole-3-butyric acid, an auxin type plant hormone that promotes rooting, among other things. IAA, indole-3-acetic acid, is the most common naturally occurring form, but IBA is more stable for long term storage so it is commonly found in root promoting hormone products.

Kirk, according to a paper (link below), IBA is slightly more stable than IAA against heat and light (in some cases). IBA is mostly synthetic (it was found in a few specie, though), so it is easier/cheaper to manufacture?

Nissen, S. J. and E. G. Sutter. 1990 Stability of IAA and IBA in Nutrient Medium to Several Tissue Culture Procedures. HortScience 25(7): 800-802 (link to full PDF)

 

[PaphMadMan]

Kirk, actually, according to a paper (link below), IAA is slightly more stable than IBA against heat and light (in some cases). IBA is mostly synthetic (it was found in a few specie, though), so it is easier/cheaper to manufacture?

Nissen, S. J. and E. G. Sutter. 1990 Stability of IAA and IBA in Nutrient Medium to Several Tissue Culture Procedures. HortScience 25(7): 800-802 (link to full PDF)

Without reading the paper, IAA may sometimes be more stable in media, but in my plant tissue culture experience it was often chosen because it would degrade, giving a gradually decreasing auxin activity over time allowing normal growth after a root initiation phase.

IBA is definitely more chemically stable in typical commercial formulations, or in pure chemical form. They are chemically quite similar, and both are easily and cheaply synthesized.

 

[Stone]

Nice save, you didn't take photos? I'm just curious, was it a vented or unvented flask?

No I didn't think to take pics. The flask was vented but I cut off the entire top so they were exposed to the air.

 

[Stone]

Very interesting. Agar on or off for the 'dosing'?

Agar on. Just opened up the flask and left it open. With the hormone, I did spray the leaves as well. They were also on bottom heat. 20C
A few other flask were similar (not just paphs) so I have repeated that on quite a few others too. Some of the paph flasks are still very good like thaianum, venustum, argus. All leaves still green and growing and active root tips, so thay are still closed for now.

 

[naoki]

That makes sense. I forgot the details but acclimation steps could be influenced by vented vs unvented. Since it was vented, and they have had higher capacity of photosynthesis (than unvented), it was probably mineral nutrient deprived (instead of carbon deprived).

Oops, Kirk, I screwed up, I meant IBA is more stable than IAA (i.e., I was saying the same thing as what you said). Sorry for the confusion. In the paper, there wasn't much difference in the decay rate between IBA and IAA in the agar based media, but in the liquid media, IBA seems to hold up much better. I corrected the post above.