S01 - Session P10 - Recent advances in sweet cherry (Prunus avium L.) breeding in Chile

Authors: Marlene Ayala *, Juan Pablo Zoffoli, Marlene Gebauer, Andrés Valenzuela, Katherine Walls

Chile is the largest sweet cherry exporter of the Southern Hemisphere. However, most of the exported commercial cultivars (e.g. 'Lapins', 'Santina' and 'Regina') are foreign sweet cherry germplasm. For this reason, in 2010 the "Consorcio Tecnologico de la Fruta" (Fruit Consortium), composed of the Fruit Export Association (ASOEX), several export companies and the Pontificia Universidad Catolica de Chile (PUC), established a new traditional genetic breeding program for sweet cherries. Its main goal is to generate new sweet cherry cultivars adapted to Chilean climatic conditions that meet export market requirements. One of the main tasks of the breeding program is to generate high quality fruit with extended storage potential. After 10 years of hybrization, a wide range of crosses (~35,000 hybrids; 3,000 to 4,000 seedlings/year) using different germplasm sources) have been established at two locations, Pirque in the Metropolitan Region (33°67'S, 70°58'W) and Coltauco in the O'Higgins Region (34°22'S, 70°99'W). Seedlings have been obtained using manual pollination and cages with bumble bees as pollinizers. Embryo rescue and seed stratification have been implemented for early and late crosses, respectively. No GA 3 and/or dormancy breakers have been used during the selection process. Currently, six generations of families have been evaluated in the field and ~3.809 hybrids have shown to be of some interest for the breeding program. From these, 116 individuals (early or late bloom and harvest, high fruit quality, high yield, low chilling requirement and high cracking tolerance) have been grafted to continue pre-commercial testing and phenotyping under commercial conditions. Among these selections harvest times have ranged from November to January, while fruit size was between 26 and 30 mm, soluble solids between 17% and 24%, and fruit firmness between 75 and 95 durofel units. Five grafted individuals have reached full production and will be evaluated for yield, quality and postharvest potential during the 2021/2022 season. Further results will be discussed in depth.