BGN 3: Towards a more efficient mutation breeding programme BARLEY GENETICS NEWSLETTER, VOL. 3, II. RESEARCH NOTES
Bhan, pp. 11-12

II.6. Towards a more efficient mutation breeding programme.

A. K. Bhan. Department of Botany, Kurukshetra University, Kurukshetra, 132119, India.

For an efficient mutation breeding program it is necessary that we have larger number of variations (mutational events) and a huge population for screening of desired plant type. It is well known that with increase in mutagen dose the seedling lethality and sterility of grains formed in M1 also increases and therefore at higher doses the breeder is left with relatively little material for screening. Thus, presently the mutation breeder has to keep a close watch on the treatment dose he is applying. The doses should not be very high lest he should get very little progeny for further studies in subsequent generations.

If somehow we could decrease the lethality and sterility of seeds induced by physical and chemical mutagens, it would be an asset to the mutation breeder.

Post-treatment of gibberellic acid has been found to show gamma ray reversal effects in wheat (Haber and Luippold, 1960), maize (Gaur and Notani, 1960), potato (Mathur, 1961) and barley (Kumar, 1967; Bhan and Banerjee, 1972). Similar effects of a post-treatment of kinetin has been found in barley (Bhan and Banerjee, 1972). Studies on barley indicate that the post irradiation treatment of gibberellic acid and kinetin enhance the mitotic index, reduce the chromosomal aberrations and almost restore the embryonal viability equal to the control (Bhan and Banerjee, 1972). Thus, the seed lethality will naturally decrease and as chromosomal aberrations are reduced one can easily postulate that seed sterility will also be lower in these populations.

It would be of great interest and importance to practically work out how far such pre- or post-treatments of growth regulators effect the mutagen treated seeds as far as reduction of seedling lethality and seed sterility is concerned and whether the mutation frequency and spectrum remains unaltered. If it is so the procedure may maximize the mutation frequency and spectrum because relatively higher doses of mutagens can be applied without the danger of obtaining high lethality of seedlings or seed sterility.

References:

Bhan, A. K. and S. K. Banerjee. 1972. Science and Culture. 38:85-86.

Gaur, B. K. and N. K. Notani. 1960. Int. J. Rad. Biol. 2:257-259.

Haber, A. H. and H. J. Luippold. 1960. Amer. J. Bot. 47:140-144.

Kumar, S. 1967. Indian J. Genet. 27(1):154-156.

Mathur, P. B. 1961. Nature, Lond. 190:547-548.

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