I recently tried to establish an initial culture of some Utricularia species such as longifolia, praelonga, livida... etc.
However, it seems the media is toxic to the explants. Every explants are really fresh and green after sterilization, but 2~3 days after place it on the media, media-contacted parts turn brown and eventually whole explant die.
My sterilization method is quite soft, 10 min in 5% bleach with few drops of soap and rinse 2 times with sterilized water, finally rinse with 0.5% PPM. My media formulation is 1/4 MS, 3% sugar, 0.8% agar, 1 ml/L PPM.
I think PPM is the problem, but it makes me worried to culture without PPM. I do not have flow hood..