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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #347100

Research Project: Breeding Stone Fruit Adapted to the Production Environment of the Southeastern United States

Location: Fruit and Tree Nut Research

Title: A major locus for resistance to Botryosphaeria dothidea in Prunus

item Mancero-castillo, D.a. - University Of Florida
item Beckman, Thomas - Tom
item Harmon, P.f. - University Of Florida
item Chaparro, J.x. - University Of Florida

Submitted to: Tree Genetics and Genomes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2018
Publication Date: 6/1/2018
Citation: Mancero-Castillo, D., Beckman, T.G., Harmon, P., Chaparro, J. 2018. A major locus for resistance to Botryosphaeria dothidea in Prunus. Tree Genetics and Genomes. 14:26.

Interpretive Summary: In the absence of any chemical control program peach fungal gummosis (incited by B. dothidea) looms as a very significant threat to the peach industry of the SE United States. Although commercial peach cultivars differ significantly in their susceptibility to this disease the vast majority fall into moderate or high susceptibility classes. Nonetheless, breeding for resistance offers the best promise for relief. The work reported on here has revealed that almond species are a potential source of resistance to PFG, easily transferable to peach. Moreover, this work has shown that the inheritance of resistance is likely controlled by a single dominant gene and is linked to leaf color. Several potentially useful molecular markers were identified that will facilitate the development of resistant peach cultivars in this collaborative project.

Technical Abstract: Species in the fungal family Botryosphaeriaceae are significant pathogens of peach. The climatic conditions in the Southeastern United States are conducive to the development of peach fungal gummosis (PFG) with an estimated yield reduction of up to 40% in severe cases. A segregating resistance phenotype was identified in interspecific crosses and segregating backcross populations generated using Kansu peach (P. kansuensis Rehder), almond [P. dulcis (Mill.) D.A. Webb], and peach [P. persica (L.) Batsch]. Hybrids were evaluated for four consecutive years in the field and these data were validated in a different environment with clonal replicates. The F1 and BC1F1 segregation data suggest a dominant allele for PFG resistance originating from almond. Segregation and mapping analysis located the PFG resistance locus on a chimeric linkage group 6-8 near the leaf color locus. The molecular markers identified will facilitate marker-assisted selection (MAS) and introgression of this resistance trait into commercial peach germplasm.