SUMMARY

The frequency and spectrum of morphological and physiological muta-tions obtained in M2 and M3 generations after sunflower immature embryos treatment with ethyl methanesulphonate (EMS) have been studied. Immature 9- 10 and 14- 15-day-old embryos of two genotypes were treated with EMS at the concentration of 0.02 % for 16 hours. Thirty-three types of mutation were found, described, and classified into the following groups: chlorophyll defi-ciency (3 types), cotyledon mutation (1), leaf mutations (6), stem mutations (9), inflorescence mutations (11), seed mutation (1) and physiological mutations (2). Differences were observed between genotypes for the spectrum and fre-quency of mutation. Mutation frequency after immature embryo treatment in the M2 generation did not exceed the amount of mutations in M3. At the same time, some mutations such as sterility, leaf venation, and different shapes of leaf lamina were unique for the M3 generation. Morphological mutations were rarest after mutagen treatment of immature 9- 10-day-old embryos. Key words: sunflower, ethyl methanesulphonate, immature embryos of differ-ent age, morphological and physiological mutations, mutation spectrum and frequenc