OPTIMIZATION OF GENETIC VARIABILITY INDUCTION BY BUD IRRADIATION OF THE Fremont MANDARIN

Among mutation breeding methods, gamma irradiation has been most widely used to induce mutation in mandarin and develop seedless. The objective of this study was aimed at identification of mutants with elite characters. 95 plants were obtained from irradiation of Fremont mandarin according to two doses 50 Gy to 70 Gy. They were grafted on macrophylla rootstock and planted in the fields of El Menzeh (INRA, Morocco) at 3x5 m² spacing. The physical and chemical quality of the fruit and juice (weight, peel color, juice content, acidity, soluble solids and maturation index) was evaluated. The statistical analysis of all studied characters showed highly significant variations among the mutants from mandarin Fremont buds irradiation. The application of mutation breeding method was aimed at identification of mutants which possess positive agro-morphological and quality characteristics.