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.

Cuticular waxes of nectarines during fruit development in relation to surface conductance and susceptibility to Monilinia laxa

“…Brown rot, which is caused by Monilinia spp., is one of the most damaging fungal diseases of stone fruit, both pre- and post-harvest. It can provoke severe yield losses, and few means of control are available other than chemical treatments ( Obi et al , 2019 ). Monilinia spp.…”

Is the Tolerance of Commercial Peach Cultivars to Brown Rot Caused by Monilinia laxa Modulated by its Antioxidant Content?

“…Based on the results found here, the degree of susceptibility to brown rot on examined peach cultivars was not associated with the large differences in harvest dates. The cultivars were harvested from mid-June to early October, but no correlation was found between harvest date and brown rot tolerance, as was reported previously in other peach germplasm [3,46]. All pathological parameters (brown rot incidence, colonization, and lesion and colonization severities) were highly correlated among them [3,46].…”

“…After five days of incubation, significant decreases of fruit firmness were found in inoculated fruits (FF3 = 29.2 N vs. FF2 = 36.2 N) due to Monilinia activity [46]. However, no significant differences were found between the soluble solid contents of control fruits (SSC2 = 14.0 • Brix) and inoculated fruits (SSC3 = 13.5 • Brix) in agreement with previous results found in other progenies [46]. Therefore, there is no credible evidence that the activities of Monilinia laxa depleted soluble solid contents in the peach, as was discussed previously [46].…”

“…The cultivars were harvested from mid-June to early October, but no correlation was found between harvest date and brown rot tolerance, as was reported previously in other peach germplasm [3,46]. All pathological parameters (brown rot incidence, colonization, and lesion and colonization severities) were highly correlated among them [3,46]. After five days of incubation, significant decreases of fruit firmness were found in inoculated fruits (FF3 = 29.2 N vs. FF2 = 36.2 N) due to Monilinia activity [46].…”

“…All pathological parameters (brown rot incidence, colonization, and lesion and colonization severities) were highly correlated among them [3,46]. After five days of incubation, significant decreases of fruit firmness were found in inoculated fruits (FF3 = 29.2 N vs. FF2 = 36.2 N) due to Monilinia activity [46]. However, no significant differences were found between the soluble solid contents of control fruits (SSC2 = 14.0 • Brix) and inoculated fruits (SSC3 = 13.5 • Brix) in agreement with previous results found in other progenies [46].…”