SCIENCE, December 23, 1949, 110 (2869): 686-687.
in Relation to Hemerocallis and Some Other Plants
Hamilton P. Traub
Division of Fruit and Vegetable Crops and Diseases, Bureau of Plant Industry, Soils, and Agricultural Engineering,
Agricultural Research Administration, U. S. Department of Agriculture, Beltsville, Maryland
Colchicum species contain appreciable amounts of colchicine (4, 5). According to Blakeslee (1) and Levan (3), Colchicum species they tested were not subject to colchicine poisoning under the conditions of their experiments.
On the basis of these reports, it would seem logical to assume that plants, other than Colchicum species, which also contain appreciable amounts of colchicine, might likewise be immune to colchicine poisoning. However, this hypothesis apparently has not as yet been tested. According to Klein and Pollauf (2), the presence of colchicine in Hemerocallis fulva L. has been demonstrated microchemically; but extensive experiments by the present writer have shown that Hemerocallis species, including H. fulva L., and various hybrid clones tested, are very sensitive to colchicine, and concentrations in aqueous solution in the range from 0.025% to 0.1%, tested with appropriate application techniques, proved to be quite effective in inducing polyploidy. Concentrations much above 0.1% usually led to the eventual death of the treated plants.
A number of colchicine-induced Hemerocallis polyploids have flowered. Their polyploid nature was established on the basis of chromosome counts, and pollen grain and stomate size. One polyploid, Tetra Starzynski, n=22, a tetraploid of the clone Mayor Starzynski, n=11, has been named. Its flowers are larger and finer-colored than those of the diploid form. This removes all doubt about the effectiveness of this compound as a mutagen in this genus. The object of the present note is not to elaborate here on these results, which will be reported in detail elsewhere, but rather to consider very briefly their implication, particularly with reference to the validity of the microchemical method used for determining colchicine.
Klein & Pollauf (2) used a microchemical procedure for the determination of colchicine in Hemerocallis fulva L. In view of the marked sensitivity to this compound of Hemerocallis species, including H. fulva L. and hybrid clones, their results require verification. If their report can be verified, then it would appear, in this instance at least, that plants which contain relatively smaller amounts of colchicine could be affected by the application of relatively larger amounts of the compound. It is also desirable to check the reported colchicine content of species in other genera. In this connection, it is of interest to note that Gloriosa rothschildiana O'Brien (a plant closely related to H. superba L., which is reported to contain colchicine) is subject to colchicine poisoning in the range tested, 0.05%-0.2% concentrations, particularly in the case of small seedling tubers.