The IVC breeding program: development of new seedless table grapevines for a sustainable viticulture

During 2015-2020, the Italian Variety Club, a consortium of growers interested in more sustainable viticulture, carried out an extensive breeding program in Puglia to produce seedless grapevines resistant to powdery (PM) and downy mildew (DM), the two most damaging grapevine diseases, and well adapted to the southern Italian climate. One hundred-nine table grapevine seedless cultivars were crossed with elite cultivars cultivated in the area or with resistant cultivars. The obtained 118.271 seedlings were subjected to marker-assisted selection for seedlessness with the marker VvAGL11, and for resistance to downy mildew and powdery mildew with 8 specific markers. The program allowed to obtain 7.696 putative seedless hybrid genotypes, corresponding to 49% of the total progeny, that were submitted to agronomic evaluation in the field, which allowed to select 10 promising cultivars which were entered in the National Register of Vine Varieties (RNVV). As for resistance, 672 seedless genotypes were found resistant to PM and DM, and 81 showed pyramidization of resistances. The work discusses the main parameters related to pollination, vernalisation, germination and plant recovery efficiency, the impact of parental combinations and other variables involved in defining the efficiency of such types of selection programmes, helping to promote a more sustainable and environmentally friendly viticulture in Puglia.