A three–decade survey of Brazilian Fusarium oxysporum f. sp. lycopersici races assessed by pathogenicity tests on differential tomato accessions and by molecular markers

• DOI: 10.1111/jam.14966
• Publication Date: 2020-12-11T16:54:09Z
• Authors: A.M. Gonçalves; C.S. Cabral; A. Reis; M.E.N. Fonseca; H. Costa; F.H.S. Ribeiro; L.S. Boiteux
• Keywords: 0106 biological sciences; Fusarium; Solanum lycopersicum; Virulence; 01 natural sciences; Brazil; Plant Diseases

Physiological race determination of 143 Fusarium oxysporum f. sp. lycopersici (FOL) isolates collected along 30 years in major tomato-producing regions of Brazil.Physiological races were determined via root-dipping inoculation of differential tomato accessions and by the PCR-based marker system of Hirano and Arie (2006). According to pathogenicity/virulence assays, five race 1, 23 race 2 and 115 race 3 isolates were identified. FOL race 1 and 2 isolates prevailed up to early 2000s. Afterwards, the large majority of the isolates was classified as the invasive race 3. Novel reports of race 3 were done in five states, thus expanding its geographical distribution. Using this PCR-based marker system, a precise discrimination was observed for all race 3 isolates. However, all race 1 and 2 isolates displayed only the cosmopolitan race 1-specific amplicon pattern.The development and/or validation of novel race-specific marker systems are necessary to allow a precise discrimination of the potentially endemic Brazilian FOL race 2.The present characterization of isolates indicates that distinct evolutionary mechanisms are acting to select new FOL races and/or genetic variants across agroecosystems around the globe.