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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #393009

Research Project: Healthy, Sustainable Pecan Nut Production

Location: Fruit and Tree Nut Research

Title: Population genetic characteristics and mating type frequency of Venturia effusa from Pecan in South America

item Bock, Clive
item FRUSSO, ENRIQUE - Instituto De Recursos Naturales Y Agrobiologia De Sevilla (IRNAS-CSIC)
item ZOPPOLO, ROBERTO - Instituto Nacional De Investigaciones Forestales Y Agropecuarias (INIFAP)
item ORTIZ, EDSON - Noble Research Institute
item SHILLER, JASON - Noble Research Institute
item CHARLTON, NIKKI - Noble Research Institute
item YOUNG, CAROLYN - Noble Research Institute
item RANDALL, JENNIFER - New Mexico State University

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/21/2022
Publication Date: 11/1/2022
Citation: Bock, C.H., Frusso, E., Zoppolo, R., Ortiz, E.R., Shiller, J., Charlton, N.D., Young, C.A., Randall, J. 2022. Venturia effusa population genetic characteristics from pecan in South America. Phytopathology. Vol 112.S3.63.

Interpretive Summary:

Technical Abstract: Venturia effusa, cause of scab, is a major pathogen of pecan in South America, and negatively impact both yield and nut quality. Population genetic characteristics of V. effusa in South America are unknown. The aim was to determine the genetic diversity and structure of V. effusa populations in South America, and the mating type frequency. Four orchards were hierarchically sampled from Argentina (AR), Brazil (BRC and BRS) and Uruguay (UR). Microsatellite markers were used to identify the multilocus genotypes of V. effusa. All orchards presented moderate to high genotypic (H = 2.85-4.74) and gene diversity (0.178-0.500), with evidence of genetic structure at 77.3% within tree level and 19.6% between orchard levels. Genetic differentiation was minimal between the UR, BRC and BRS populations, but were more clearly differentiated from the AR population. The MAT1-1 and MAT1-2 mating types occurred in all four orchards and were at equilibrium, indicating the pathogen is undergoing sexual reproduction in South America. The characteristics of the population genetics of South America populations of V. effusa have many similarities to those previously described for populations of V. effusa in the U.S.A. Knowledge of the populations genetics and reproductive systems of V. effusa is useful to establish the evolutionary potential of the pathogen, and its adaptability. Furthermore, the knowledge can provide a basis for informed approaches to utilizing available host resistance and identifying phytosanitary needs.