Fungal Growth in Taro Tissue Cultures

 Taro explant with Latent Fungus

Liquid Media Suppresses Fungal Growth

The University of Hawaii Tropical Agricultural College puts out a mini-manual on taro tissue culturing which can be downloaded here.

I've tried this in the past (check this video) and always have had problems with mold/fungus growing on the explants. Right before taking that video, I'd wash off the thick white fungal growth with a toothbrush under running tap water and placed the now cleaned up explant into a brand new media container and then shoot the video...

...but sure enough almost like clockwork, in about three to four day's time, the white fungal growth would be back with a vengeance. So my video is somewhat B.S., ya know?

And I've tried different methods to get rid of the fungus, like using PPM™ (Plant Preservative Mixture -biocide/mildewcide), alcohol washings, another mildewcide for paints, bleaching out the fungus, etc. But like CLOCKWORK, within 3 days the fungus would be back no matter what.

The taro plants (where I get explants from) that I grow in the ground behind my house does not show any fungus. I believe however that fungus is latent in my taro corm pieces and this of course transfers to the explants that I use.

My second technique namely MERICLONING tissue culture is using just the true meristem material. In the case of taro, this mericlone is awfully tiny ...under 1mm (around 1/32 inch) in size! Dealing with plant material this small is a lot of extra work and really requires a dissecting microscope at least 40x power.

The payoff is that you'll greatly lessen any chance of latent fungus/mildew or even viruses from being unknowingly transferred along with your explants into your sterile test tube containers.

And this is the empirical evidence that backs it up...

So far this mericloning technique shows no evidence of fungus in 23 of of 26 test tubes! Nothing but nice green plant growth after TWO WHOLE WEEKS in 21 out of 26 test tube cultures. I'm certain that any fungal growth would have showed up by the first week (like it did in three cultures). So 21 test tubes have tested clear of any fungus mold. Whoa!

I finally... FINALLY.... can get my taro plants into tissue culture without fungal growth. Be happy for me!