(no subject)

Fri, 11 Nov 1994 09:45:47 -0500 (CDT)

Subj: RE: Radiation and VFTs

Matt Thompson ( MBT1159@ACS.TAMU.ED) said:
> I am not familiar with colchachene treatments. I had heard on this
>list before, however, that increasing the N would only increase the number
>of petals on the flower. ...

Colchicine (same drug that's used for gout!) interferes with the
separation of chromatids (identical copy chromosomes) during cell
division. The net effect is usually a doubling of the chromosome
number in untreated cells. Most plants with doubled chromosome numbers
are larger (and often have larger cells and stomata) than untreated
plants. In my experience, petal number does increase with chromosomal
doubling. I don't know of any study specifically addressing colchicine
treatment of carnivorous plants, but I'd expect these plants to be

As to mutation breeding, it was extensively tried by breeders of crop
plants for a number of years, with very disappointing results. In
general, the mutants obtained were of much poorer quality than the
unmutated plants (well, that's pretty much what you'd expect: it's
easier to screw up a complex process (life) than improve it). I
don't know of anyone seriously doing mutation breeding now unless the
available genetic material is so variation-poor that the breeder
feels forced to try mutation breeding.

Kay Klier klier@cobra.uni.edu