FORUM IN VITRO

Milos, it is very well possible that the foodstore agar had some Fe impurities in it (the water was R/O). If you can send me some Fe in chelate form that would be great!
Sativ: the amount of citric acid I need for pH adjustment is never more than 20mg/l. You think it is toxic for explants? I do not have MES (if you think of morpholinoethanesulfonic acid), so I will get to KOH and HCl like Michal says.
The N-burning is out of game I think since Michal had more N in his media and it worked well. You might be right about the overheating problem though. I was not present at the time it happened, so i do not know what was the temperature in the jars.

Here are the pics of some survivors, they are doing well and recovered without any permanent damage




Luckily now I have in hand some new seeds of d. ascendens (localized and the red form), so I will sow them on media some time next week and will report here about the results:-)

So have done the drosera ascendens culture again, and it seems that the previous troubles were caused by too high nitrate content. This time i mixed a different ratio of chemicals and have massive germination of drosera ascendens 'red form' seeds and subsequently, a nice fresh subculture.

Here is an update on my drosera ascendens "red" subculture.

Hi,

Last week, about 10 ascendens germinated on MS /3 like you. For instance nothing special, they are very small but grow without toxicity symptoms. I'll update later.

I already have this kind of symptom and i think it was the pH. because I had a bad low-cost pH-metre.
Maybe it is the same with yours. My new pH metre have also a little problem, the connection between the probe are not very good and in some position, the pH are too low....

It's strange you have to decrease pH with acid. Normally you have to increase pH with KOH with a initial pH at about 4. What was your initial pH before adding citric acid?

I reply to your post because i don't think your problem was nitrogen. A high level nitrogen cause high duplication of the plant and no glue. Generally the plant don't grow much.

Hi!
You are right. Some time ago, I diagnosed my problem with some dying plants (case of abovementioned as well),- it was definitely too high pH caused by agar. I have always measured pH (very precise, high quality pH meter), before addition of agar and melting. I found out that some agars raise the pH from original 5.5 to as much as 7.1! At such pH drosera dies. Now I always adjust the pH so it is 5.4-5.7 AFTER solidification and cooling (pH changes with temperature). I use HCl for adjusting the pH. I am glad I found the reason, now the cultures are doing just fine:-) Thanx for your input though.

Many medias don't have inositol and most plants grow well.

Hi Dusan,
this does look like something is toxic in your medium. I dont know D.ascendens, but 20mM of nitrogen ( 6,6mM of NH4 ) can be too high.Also check your micronutrients ( KI, CuSO4 can be pretty toxic to CP )