| The differences in survival percentage between varieties and doses were highly
significant. There was no significant difference between varieties C 306, WH 157 and
Kalyansona and also between Sonalika and WH 147 as far the survival is concerned. The
survival percentage has been associated with mutation frequency by several workers.
According to one group of workers, the mutation frequency does not follow the linear increase
with radiation dose. With medium or higher doses either a saturation effect or a decrease
of mutation rates was observed. In contrast, GAUL (1963) demonstrated that the increase
is linear with dose. In some cases, he even found exponential increase of mutation rates
upto the highest killing rate namely 99 per cent of the treated seeds. This is in contrast
of other scientist who proposed the use of a dose which results in 50 per cent survival. This material has also produced desirable type of mutants which are being screened for various traits regarding their purity and desirability. References CAMPOS, F.F., GENEROZA, W.M. and CQPINPIN, J.M. 1960. Effect of X-rays on the bulbs and seeds of onion (Allium cepa L.). Phillip. Agri. 44: 125-33. CHOWDHURY, R.K. 1982. Induced quantitative variation in wheat. WIS, 54: In press. FUJII, T. and MATSUMURA, S. 1966. Comparison of mutagenic efficiency between ethyl-methane- sulphonate and ionizing radiations in diploid wheat. Seiken Zihe. Report of the Kihara Instt. for Biol. Res. Yokohama, Japan. GAUL, H. 1963. Induced mutations in plant breeding. Genetics Today. Proc. XI Int. Congr. Genet. The Netherlangs, Sept. 1963: 689-709. GAUL, H. 1964. Mutations in plant breeding. Rad. Bot. 4: 155-232. MIKE, A. 1975. Induced mutations in plant breeding. Canadian J. Pl. Sc. 55: 865. |
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