Breeding strategies for identifying superior peach genotypes resistant to brown rot

Abstract

A sustainable approach to control the incidence of brown rot in pre- and post-harvest management is to select genotypes with high contents of antioxidant compounds and tolerance to Monilinia laxa (Aderh. and Ruhland) Honey. In this study, 68 progenies of the ‘Babygold 9’ × ‘Crown Princess’ population from the EEAD-CSIC breeding program were screened under controlled conditions for a period of 3 years (2013–2015). Susceptibility to brown rot was evaluated after inoculating 20 healthy fruits per genotype with M. laxa. Brown rot incidence, lesion diameter, and colonization extent, as well as the severities of these issues, were calculated after 5 days of incubation. Physicochemical traits, such as fruit firmness and soluble solids content, were also recorded before and after storage. Titratable acidity, pH, and antioxidant composition were measured at harvest. Significant differences were found for pathogenic traits, as well as for contents of vitamin C, total phenolics, flavonoids, and anthocyanins, within genotypes in this population. Negative correlations were also found between the content of phytochemical compounds (such as anthocyanins and total phenolics), as well as disease incidence and severity. Differences in susceptibility to brown rot confirm the genetic variability available in these progeny. This allowed the selection of six genotypes highly resistant to brown rot of M. laxa, with high organoleptic properties and high phenol content, to be introduced in our peach breeding program.