RESULTS ON GENETIC VARIABILITY IMPROVEMENT BY SEXUAL HYBRIDISATION IN SWEET CHERRY TO OBTAIN NEW VALUABLE GENOTYPES

Abstract

Expanding the genetic variability is an essential condition for achieving the goals in the cherry breeding programme. Sexed hybridization is known to be the only conventional method that can generate many descendants with a continuous spectrum of genetic variation. The study of the genetic nature of parental cultivars and the transmission of traits followed by the breeder to their descendants is highly important for improving the selection efficiency. The studies took place between 2018-2021, using 14 sweet cherry cultivars as research material: seven new cultivars (‘Cătălina’, ‘Maria’, ‘Croma’, ‘George’, obtained by hybridization and ‘Margonia’, ‘Andante’, ‘Croma’ obtained by open pollination) and seven cultivars being used genitors (‘Van’, ‘Stella’ ‘Boambe de Cotnari’, ‘Ciliegia di Ottobre’, ‘Fromm’, ‘Lijana’, ‘Bigarreau Drogan’). Each cultivar was compared against their genitors (♀ × ♂). The values of the fruit’s size in the new cherry cultivars were between 7.2 g and 23.2 mm (‘George’) and 7.7 g and 24.2 mm (‘Cătălina’, ‘Muşatini’, ‘Croma’) and the soluble dry substance was between 16.4 (‘Margonia’) and 19.9 (‘Cătălina’). In terms of fruits’ resistance to cracking it was statistically determined that the seven studied cultivars [‘Cătălina’ (6.6%), ‘Muşatini’ (3.9%), ‘Maria’ (9.3%), ‘Croma’ (19.3%), ‘Andante’ (11.0%), ‘Margonia’ (1.5%) and ‘George’ (5.8%)] have a higher level of resistance in comparison with genitors.