APPLIED PLANT GENETICS AND GENOMICS FOR IMPROVING RESISTANCE TO XYLELLA FASTIDIOSA

The genetic improvement of crop plants is a key strategy to adapt agricultural production to climate change, invasive pathogens, higher demands on product quality and quantity, and product differentiation. Conventional breeding is a long-established strategy for crop improvement, but it can take many years to bring innovative crosses onto the market and, in addition, can lead to the loss of distinctive traits of elite cultivars. The direct transfer of genes and other genetic elements into elite crops produces genetically modified (GM) varieties with desirable features much more rapidly than conventional breeding, but the GM –derived plant materials are hampered by health and environmental safety concerns. Actually, the limitations of conventional breeding and GM technology can be overcome by genome editing, which accelerates basic research and plant breeding by allowing the rapid introduction of targeted mutations. The cultivated olive (Olea europaea, subsp. europaea, var. europaea) is one of the most important oil crops in the world and 95% of total olive oil production derives from the Mediterranean Basin. The olive crop counts a very rich varietal heritage, represented by more than 1,200 named cultivars, over 3,000 minor cultivars and an uncertain number of genotypes including pollinators, local ecotypes, and centennial trees. Among these, only a few have a large area of cultivation and a clear impact on the production of oil and table olives. Contrariwise, the availability of a large set of well characterized and highly different cultivars is critical to increase the ability to face new agronomical challenges and future climatic constraints, diversifying the gene pools and preserving unique genetic traits currently available. The overall objective of the project is to develop genomics tools and to identify the bases of resistance to Xf for their application in germplasm screening, genomics-assisted breeding and generating new Xf-resistant olive genotypes. To reach this ambitious objective, critical steps are the generation and analysis of massive genomic datasets, the establishment of transformation and regeneration tools from single and multiple cell explants for a successful application of DNA-free genome editing protocols. To address the challenges posed by the notorious recalcitrance of olive in vitro manipulations, EU and national research centers representing leading research teams in genomics, genetic improvement technologies and in vitro cultures are being involved.