[en] Full text: Sweet orange cultivar ''Mestnyi'' (local) was treated with chemical mutagens and gamma rays. Mutant 4790 resulted from chemical mutagenesis, mutant 563 from gamma irradiation. The mutants vary in content of vitamin C, sugars and acids, in fruit weight and yield. Seeds of the mandarin cultivar ''Unshu'' (satsuma) were treated with NEH. Among 111 variants, 31 were dwarfs, 24 had stronger vigour, 8 showed increased, 5 reduced fruit size, 10 were earlier, 28 later. The reason for the wide variation may be a complex hybrid origin of the ''Unshu'' mandarin. (author)