View Full Version : When clones are NOT clones--Somaclonal Mutations
Simply Bananas
08-16-2008, 04:32 PM
I found this mentioned when researching Kandrian banans.
http://www.fshs.org/Proceedings/Password%20Protected/1998%20Vol.%20111/296-299%20(PLOETZ).pdf
On page 298, left column, the paragraph that starts, "one of the risks that are inherent..."
goes on to state that some TC plants are 50% shorter than they are supposed to be.
I believe that this may explain two of my previous queries:
http://www.bananas.org/f2/dwarffing-my-ele-eles-2538.html
and
http://www.bananas.org/f2/pisang-raja-4909.html
Dean W.
08-17-2008, 03:54 PM
Makes you not want to buy TC bananas.
Tropicallvr
08-18-2008, 01:53 PM
I wonder how often that happens at big suppliers like Agri-starts. I wonder if could have to do with using the wrong portions of hormones and such, or it just depends on the species?
harveyc
08-24-2008, 03:43 PM
Gabe and I were discussing an unknown banana that was claimed to be a TC mutation. Gabe indicated that mutations in TC are fairly uncommon and rarely seen by an individual grower. The mutation rates are described in one of his books back at school; maybe he can follow-up on this discussion. He did say that they typically will not subculture a line more than four times to reduce the risk of mutations and then resort back to collecting material from an old established plant.
Tropicallvr
08-24-2008, 07:01 PM
Thanks that's some good info. I have bought some mutants from a guy who goes through one of the big wholesale nurseries looking for varigation. I forget what percentage it happens, but enough so that he went back on a regular basis to look through a few thousand for on plant.
Also, that's the impression I was under, that you can't clone over and over too many times or you start getting genetic defeincies (had an argument awhile back on this same subject on one of the banana forums). I'll bet M.basjoo has gotten cloned on top of clone a few times.
Chironex
10-31-2008, 12:44 PM
Sometimes the dwarfing aspect of TC derives from induced mutation, other times it can come from using the same explant material too many times. In some cases, dwarfing is a sought after trait. Varying hormone levels in the medium can also produce sports with odd traits. In general, however, it is the exception and not the rule.
Richard
10-31-2008, 02:05 PM
I believe that the percentage of mutations that occur among natural pups (plants in the ground) is higher than the TC percentage under "normal" conditions.
Gabe15
10-31-2008, 03:27 PM
Mutations rates vary widely by variety and method, from 0% up to 70% (this includes all detectable variations, it doesn't mean they are all inferior, undesirable, or even meaningful). Its observed that generally if you keep reculturing the same explants you will get higher rates of mutation, but there are other factors that contribute to affecting mutation rates such as: the variety being cultured, the amount of explants produced, hormones (type and amount present in medium), initiation method, stock plant source (could be from a previously TCd plant, from an old normal plant, somatic embryo genesis, seed, axilary bud culture as opposed to apical...).
Alternatively this is also induced and desired in breeding programs when betting on the off chance that one of the somaclonal variations may actually be beneficial (though statistically unlikely).
As for predicting the mutation rates you will see in TCd plants on the hobby market (and the reason behind those mutations)? Who knows, you would have to do lengthy studies at specific labs, document their methods and mutation rates, and then compare the results to other commercial labs.
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