Jour. of Heredity 53(6): 304-308 (1962)
Colchicine-Induced Mutations in Sorghum Which Affect Qualitative Character
A. W. Erichsen, C. J. Franzke, M. E. Sanders, J. G. Ross*

Diploid mutants of Sorghum vulgare, obtained in certain varieties by treating seedlings with a 0.5 percent colchicines-lanolin mixture, are peculiar because they differ in many characteristics from the untreated varieties from which they were derived. Also, the majority are true-breeding.1,4-6,15 Colchicine is well known for its influence in causing polyploidy in plants, but cytological studies have shown that the chromosomes of the true-breeding sorghum mutants are diploid and behave regularly at meiosis.10 Mutants have occurred with high frequency in the true-breeding variety Experimental 3; some have been obtained in Experimental 1 and by retreatment of previously obtained mutants.7

Studies of pairing relationships at the pachytene stage of meiosis in F1 hybrids between mutants and the original variety indicated that no relocation of chromatin had occurred in the mutants. Therefore, it would seem that point mutations must have occurred.10 In a colchicines-induced grass-type mutant, Foster studies qualitatively and quantitatively inherited mutant characters and found typical Mendelian inheritance.4

*Contribution from the Agronomy Department, South Dakota Agricultural Experiment Station, Brookings. Approved for publication by the Director of the South Dakota Agricultural Experiment Station as Journal Series No. 540. This investigation was supported in part by research grant PH.S. C-2086 from the National Cancer Institute and research grants NSF-F5489 and NSF-G14990 from the National Science Foundation.