Determination of optimal mutagen dosage and its effects on morpho-agronomic traits in putative mutants of ‘Amasya’ apple

Abstract

Atay A. N., E. Atay, B. Kunter, K. Y. Kantoglu, N. Kaplan (2019): Determination o f optimal mutagen dosage and its effects on morpho-agronomic traits in putative mutants o f ‘Amasya ’ apple.Genetika, Vol 51, No.2, 629-639. Mutation breeding is one of the efficient ways to create new genotypes. The starting material of this study was the ‘Amasya’, a Turkish apple cultivar. This study aimed to identify optimal mutagen dosage that is the most important prerequisite to create a proper mutant population, and evaluate the genetic variability for morpho-agronomic traits (e.g. tree height and fruit number) in the putative apple mutants of ‘Amasya’ irradiated at the optimal mutagen dosage. In the first year of the study, to determine the optimal mutagen dosage, dormant ‘Amasya’ scion woods were irradiated at 0, 10, 20, 30, 40, 50 and 60 gray dosages using 60Co source. The optimal mutagen dosage was determined as 29.01 gray for ‘Amasya’ concerning the 50% shoot length reduction in comparison to the non irradiated control plants. In the following year, more or less 2000 dormant ‘Amasya’ scion woods were irradiated at the optimal mutagen dosage to generate a mutant population of ‘Amasya’ apple cultivar. Mutation frequency based on the visual observations of plant abnormalities was observed. Then three years, genetic uniformity