S02 - Session O4 - II - Characterizing and unravelling the agronomical potential of stone fruit crop wild relatives

Authors: Veronique Decroocq *, Amandine Cornille, Shuo Liu, Stéphane DECROOCQ, Quynh Trang Bui, Alexis GROPPI, Tatiana GIRAUD

Because of their long-term cultivation, fruit trees are susceptible to ever-changing environments due to climate changes and pathogen outbreaks. Sustainable fruit production relies on introducing natural, genetic resistance to diseases and pests when available in the cultivated germplasm. However, bottlenecks during plant domestication and subsequent breeding have reduced genetic diversity and lost valuable alleles within genes not directly targeted by human selection. Consequently, important traits, such as resistance to pests or diseases, may be absent in the cultivated germplasm while they may be present in crop wild relatives. The challenge is thus to investigate the genetic and phenotypic diversities of wild close relatives of crop species to identify resistance traits that can be introgressed into elite lines in future breeding programs. Here we focus on the fruit tree species Prunus armeniaca (apricot), native to Central Asia, where it is still present in the wild, in the Tian-Shan forests of the Himalaya. We have found that these natural populations exhibit broad and original genetic diversity and a high frequency of resistance to pathogens, among which the agent of Sharka disease, the plum pox virus. Bayesian statistical approaches in population genetics allowed us to infer the evolutionary history of this perennial species and trace the origin of the cultivated European and Chinese apricot. From this genome-wide data, we identified genomic loci and genes targeted by domestication in apricot; the use of this information in breeding programs is currently assessed.