Evaluation of pear ( Pyrus communis L.) hybrid combinations for the transmission of fire blight resistance and fruit characteristics

摘要

Fire blight is one of the most destructive diseases of pome fruits, especially pears. In current conditions when the demand for organic products is increasing, improvement of resistant rootstock and varieties is becoming important due to the lack of an effective disease management method against fire blight caused by Erwinia amy-lovora as well as the harmful effects of chemicals on environment, human and animal health. The findings of the researchers as to which variety performs well in terms of the transmission of fire blight resistance are quite important for new breeding programs. In the study, three varieties with high commercial value (Magness, Santa Maria and Williams) were identified as the maternal parents and 21 hybridization combinations were made with seven varieties (Ak?a, Ankara, Conference, Güz, Kaiser Alexandre, Kieffer and Ta?) as pollinators. The Magness maternal parent was found superior when compared with the other maternal parents for the variety susceptibility level to fire blight. Apart from the differences in the susceptibility level of 21 different combinations of hybrids to fire blight, the commercially superior ten hybrids (I-15-24, II-13-1, II-13-19, II-13-34, II-13-73, II-27-21, II-27-55, II -32-44, III-22-638, III-27-590) have been determined via the weighted ranking method from the parameters of disease resistance and different fruit characteristics measuring the commercial preference of the fruits such as fruit quality, attractiveness, size, firmness and rustiness.