Fulvia fulva [syn. Cladosporium fulvum, Passalora fulva] races in Argentina are evolving through genetic changes and carry polymorphic avr and ecp gene sequences

The aim of this work was to study further the population of Fulvia fulva [syn. Cladosporium fulvum, Passalora fulva] in Argentina particularly in terms of diversity at the genetic level by means of ISSR. Also, we studied polymorphisms within avr and ecp sequences, what incidentally might lead to the development of new races. Argentinian tomato cultivars only are affected by two races of F. fulva and the data we provide here indicates that the populations of these two races are under an evolutionary process. Representatives of them had several polymorphisms within the coding sequences of effectors, but they are not constrained to avr genes, probably because, based on field data, resistant cultivars are not available. Most polymorphisms observed in avr and ecp genes were deletions or insertions (INDELs) or single nucleotide polymorphisms (SNPs). Therefore, probably the environment and management practices are the most important factors driving evolution of these races in Argentina and this might explain why the pathogen population is not driven at the pathogenic or race level.

Automated summary

This study aims to further investigate the population of Fulvia fulva in Argentina, particularly in terms of genetic diversity, and studied polymorphisms within avr and ecp sequences, which may lead to the development of new races. The results show that the two races affecting Argentine tomato cultivars are under an evolutionary process, with polymorphisms observed mainly in coding sequences of effectors. The evolution of these races in Argentina may be primarily driven by environmental factors and management practices, rather than specific pathogenic or race-related genes.