Integrating phenotypic and genetic diversity to breed for Sunflower Verticillium Wilt resistance

MONTECCHIA JF; FILIPPI C; FASS M; MARINGOLO C; CERRUDO IGNACIO; DOMINGUEZ M,; HOPP E,; ESCANDE A,; DI RIENZO J; GONZALEZ J; ALVAREZ D,; QUIROZ F,; LIA V,; PANIEGO N,; HEINZ R.

San Diego

Congreso; Plant & Animal Genome XXVI Conference; 2018

Fungal diseases represent a serious constraint for sunflower (Helianthus annuus L.) grain and oil production worldwide. Sunflower Verticillium Wilt (SVW), caused by the soil-borne fungal pathogenVerticillium dahliae (Kleb.), is one of the most threatening diseases in Argentina due to its prevalence and variability. V.dahliae is an endemic pathogen spread over an extensive area of 1.2 millionhectares (Pereyra y col., 1999), where 70% of sunflower national production is grown. Among the plant pathogenic species of the genus Verticillium (Ascomycota), V.dahliae and V.alboatrum are themost damaging ones, causing vascular wilts in up to 250 dicotyledonous plant species. Melanized microsclerotia constitutes the inoculum source which is released from the decomposing plantdebris. Microsclerotia show long term viability and remains infective in soil from 10 to 15 years (Pereyra y Escande, 1994). Chemical control is not an effective strategy for SVW prevention. Thus,resistance breeding is the most promising strategy to cope with this affection from an ecological and an economical perspective.This work takes place within the frame of a doctoral thesis ´s research project that aims to identify and characterize genetic resistance sources against SVW through a combined approach betweenLinkage Mapping and Genome-Wide Association Studies (GWAS). Here, we explore the genetic diversity and the phenotypic response against SVW of 164 inbred lines from an association mappingpopulation (IAMP) as the first step prior to GWAS. The main goals of this work were (a) to evaluate the response of the IAMP to SVW by multivariate analysis, and (b) to assess the relationshipbetween resistance response and genetic structure.