摘要：Gamma irradiation
mutagenesis is a technique commonly used to induce seedlessness in citrus
fruits. We compared fruit quality traits of eight different
seeded mandarin varieties within the Israeli citrus breeding collection with
those of their corresponding gamma-irradiated low-seeded mutants. The mandarin
varieties compared were: “Rishon” with “Kedem”; “Michal” with irradiated “Michal”;
“Merav” with “Meravit”; “Vered” with “Vardit”; “Ora” with “Or”; “Murcott” with “Mor”;
“Shani” with irradiated “Shani”; “King” with irradiated “King”. Mutational
breeding by gamma irradiation reduced average fruit seed number by 70% - 92%. Furthermore, mutational breeding by gamma irradiation delayed ripening
of the early-season mandarin varieties “Rishon” and “Michal” by 8 - 13 days,
but did not delay ripening of most mid- and late-season varieties. Gamma-irradia-
tion mutagenesis also reduced fruit weight of seven of the eight tested
low-seeded varieties by 6 - 41 g per fruit. Gamma-irradiation mutagenesis had
variable effects on biochemical composition and nutritional quality, in that some
irradiated clones presented no changes whereas other had either higher or lower
levels of juice total soluble solids, acidity, vitamin C and total antioxidant
activity. Finally, sensory evaluations by a trained panel revealed that the
flavor of most of the low-seeded, gamma-irradiated varieties was slightly or
significantly preferable to that of unirradiated varieties.
关键词：Citrus; Gamma Irradiation; Flavor; Fruit Quality; Mandarin
