II.22. Efficiency of inducing mutations with chemical supermutagens in relation to barley genotype, mutagen specificities and concentrations.
M. R. Kozachenko and V. T. Manzyuk. Ukrainian Institute of Plant Industry, Plant Breeding and Genetics, Kharkov, U.S.S.R.
The comparative studies on mutability effects have been carried out in sixteen experiment variants such as: the treatment of spring barley cultivars Kharkovsky 60 and Kharkovsky 410 for 12 hours with 0,01, 0,02 and 0,05 % N-nitroso-N-ethylurea (NEU) and 0,006, 0,01 and 0,015 % N-nitroso-N-methylurea (NMU); the treatment of these two as well as the cultivars of Kharkovsky 306, Medicum 52-84, Kombainer and seeds of F2 Yubileiny x Yuzny with 0,01% NMU. Mutations were induced within M2-families (the progenies of 6271-st M1-ear) and in M2-population (about 195000 seedlings and about 167000 plants at the time of harvest). The mutant nature of M2 changes have been established in M3.
The results of treatment trials were as follows (depending on cultivar, mutagen specifities and concentrations): 2,30 to 19,85% mutant M2-families; 4,90 to 37,27% mutant M1-plant progenies; 2,30 to 21,63 mutations per 100 M2-families, and 6,29 to 52,80 M2 mutations per 100 M1-plant progenies. Thus, in every 5th - 43rd M2-family and nearly in every 3rd 20th M1-plant progeny a certain M2 mutation has been observed as depending on trial variants.
Increased number of mutations has been induced in the trial variants as follows: 0,05% NEU treatment of Kharkovsky 410 and 0,02% NEU treatment of Kharkovsky 60 resulted in the greatest number of mutations (52,80 and 48,28 mutations per 100 M1-plant progenies, respectively); 0,015% NMU treatment of the same cultivars resulted in somewhat less number of mutations (43,73 and 44,63, respectively).
Among six barley cultivars treated with 0,01% NMU the most respondent proved to be Kharkovsky 306 (34,43 mutations, i.e., several times as much as in other forms studied). This is in accordance with the data obtained in radiation mutagenesis trials which show the high efficiency of mutation inducing treatment of this cultivar.
Thus, the results of this study showed the high efficiency of producing mutations by new chemical supermutagens. Genotypically different cultivars showed different induced mutabilities. To a considerable extent these mutabilities were determined by mutagens and their concentrations used. NMU proved to be the more effective mutagen. 0,01% NMU has induced more variations (9,86 and 12,50 mutations per 100 M1-plant progenies of Kharkovsky 60 and Kharkovsky 410, respectively) as compared to the same concentration of NEU (6,29 and 9,16 mutations, respectively). However, as the data obtained showed, with the suitable supermutagen concentrations one can succeed in obtaining high mutation frequences following NEU and NMU seed treatments.
References:
Kozachenko, M. R. and V. T. Manzyuk. 1973. Chemical mutagenesis in barley in relation to mutagen specificities and concentrations and cultivar genotypes. In sb.: Selectia i semenovodstvo, v. 25. Kiev, U.S.S.R. (In press).