Characterization of Pathogenic and Nonpathogenic Fusarium oxysporum Isolates Associated with Commercial Tomato Crops in the Andean Region of Colombia.

Sandra L Carmona,Jaime Simbaqueba,Jairo Castaño-Zapata,Walter Lopez,Diana Burbano-David,Mauricio Soto-Suárez,Nelson Ceballos,Magda R Gómez

doi:10.3390/pathogens9010070

Sandra L Carmona, Jaime Simbaqueba + Show 6 more

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https://doi.org/10.3390/pathogens9010070

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Abstract

In Colombia, tomato production under protected conditions represents an important economic contribution to the agricultural sector. Fusarium wilt diseases, caused by pathogenic formae speciales of the soil-borne fungus Fusarium oxysporum Schltdl., cause significant yield losses in tomatoes throughout the world. Investigation of the F. oxysporum–tomato pathosystem in Colombia is required to develop appropriate alternative disease management. In this study, 120 fungal isolates were obtained from four different departments in the Central Andean Region in Colombia from tomato crops with symptoms of wilt disease. A molecular characterization of the fungal isolates was performed using the SIX1, SIX3, and SIX4 effector genes of Fusarium oxysporum f. sp. lycopersici W.C. Snyder & H.N. Hansen (Fol). Additionally, we developed a new specific marker to distinguish between Fusarium oxysporum f. sp. radicis-lycopersici Jarvis & Shoemaker (Forl) and Fol isolates. Furthermore, a phylogenetic analysis using the Translation Elongation Factor 1-alpha (EF1a) gene was performed with the collected isolates. Two isolates (named Fol59 and Fol-UDC10) were identified as Fol race 2, four isolates were identified as Forl, six isolates were identified as F. solani, and most of the isolates were grouped within the F. oxysporum species complex. The phylogenetic tree of EF1a showed that most of the isolates could potentially correspond to nonpathogenic strains of F. oxysporum. Additional pathogenicity assays carried out with Fol59 and Fol-UDC10 confirmed that both isolates were highly virulent strains. This study represents a contribution to the understanding of the local interaction between tomatoes and F. oxysporum in Colombia.

Highlights

Fusarium oxysporum is a ubiquitous species complex of fungi that includes soil-borne plant pathogenic lineages that are the causal agents of vascular wilt disease in a broad range of plant species, such as bananas, cotton, tomatoes, and legumes [1,2,3,4]
Region regarding wiltColombian disease and the types of chemicals applied to control the wilting disease symptoms questions (i) Has tomato crophybrid been affected by Fusariumcollected wilt in the
Varietal resistance is a highly efficient alternative to control the disease, using a number of commercial tomato hybrid varieties derived from the introgression of resistance genes specific to Fol races 1 and 2 [11]

Summary

Introduction

Fusarium oxysporum is a ubiquitous species complex of fungi that includes soil-borne plant pathogenic lineages that are the causal agents of vascular wilt disease in a broad range of plant species, such as bananas, cotton, tomatoes, and legumes [1,2,3,4]. Tomatoes are one of the most important vegetable crops worldwide [8]. Their production is severely affected by diseases caused by pathogens. Vascular wilt and crown root rot diseases caused by Fusarium oxysporum ff. Spp. lycopersici (Fol) and radicis-lycopersici (Forl), respectively, are responsible for substantial yield losses (up to 80% in severe epidemics), and they coexist in the same fields as tomato crops [6,9,10,11,12] Vascular wilt and crown root rot diseases caused by Fusarium oxysporum ff. spp. lycopersici (Fol) and radicis-lycopersici (Forl), respectively, are responsible for substantial yield losses (up to 80% in severe epidemics), and they coexist in the same fields as tomato crops [6,9,10,11,12]

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