SWEET CHERRY BREEDING PROGRAMME AT THE SWISS FEDERAL RESEARCH STATION I. RESULTS OF FRUIT CHARACTERS AND FLOWERING PERIOD INHERITANCE

Sweet cherry breeding in Switzerland started in 1955/57 and resulted in the release of four new cultivars: Alfa, Beta, Gamma and Delta. Between 1968 and 1972 new crossings were carried out to obtain sweet-sour tasting sweet cherries and resistance to bacterial canker infection. At this time a new breeding scheme was initiated to combine bacterial canker testing, fruit character inheritance studies and optimum land use.

Seeds were grown by embryo culture and for one year in the nursery. After that time they were cultivated in a dense plantation trial on their own roots for the first test period. During that time of about 8 to 10 years, evaluations of tree- and fruit characters and bacterial canker testing were carried out as well as the first selections. From selected seedlings scions were grafted on F12/1 rootstocks and prepared for further tests in a field trial where again selections will follow.

In the first part results are given on fruit-colour and -size inheritance in progenies as well as the transgression of late flowering by back crossings. In a second part results on bacterial canker resistance of cultivars and seedlings and the programme for the new breeding cycle 1978–1980 are presented.