CREATION ET EXPERIMENTATION DE VARIETES DE POMMES ADAPTEES A L’AGRICULTURE BIOLOGIQUE

Summary

Our apple breeding program is based entirely on the results of our work to safeguard, evaluate and valorize the rich heritage of apple tree genetic resources in our regions. Since 1975, no fewer than 1800 introductions have been collected in our collections and, taking into account duplicates, errors and synonyms, this represents a total of about 850 distinct cultivars. These are systematically evaluated in experimental orchards that do not undergo any treatment. Some cultivars that are highlighted for their high level of resistance to the main diseases as well as for their agronomic and quality characteristics of trees and fruits are used as parents. Our priorities are mainly focused on the expansion of the apple's genetic base, polygenic resistance to the main diseases (scab, powdery mildew, canker) and a whole series of characteristics present in certain old and peasant varieties such as long natural conservation, rusticity, robustness, frugality, nitrogen efficiency, tree architecture and the nutritional qualities and properties of the fruit. These parents are then crossed with varieties, often more commercial, which offer advantages in terms of speed of fruiting, yield, flesh quality and tree architecture. The current plant breeding program is based on extensive methodological work that has been developed specifically to select materials with partial disease resistance that express good potential for adaptation to simple and 'low-input' crop conditions. About sixty elite selections from our work are currently being tested in organic farming and are compared with 48 other new commercial varieties in order to look for varietal alternatives that are much better adapted to organic production than those currently being grown. Partial results of about twenty selections and varieties are presented, including results relating to the sustainability of a panel of varieties carrying the Vf gene.