The Fusarium oxysporum f. sp. ciceris/Cicer arietinum pathosystem: a case study of the evolution of plant-pathogenic fungi into races and pathotypes.
The use of resistant cultivars is one of the most practical and cost-efficient strategies for managing plant diseases. However, the efficiency of resistant cultivars in disease management is limited by pathogenic variability in pathogen populations. Knowledge of the evolutionary history and potential of the pathogen population may help to optimize the management of disease-resistance genes, irrespective of the breeding strategy used for their development. In this review, we examine the diversity in virulence phenotypes of Fusarium oxysporum f. sp. ciceris, the causal agent of Fusarium wilt of chickpeas, analyze the genetic variability existing within and among those phenotypes, and infer a phylogenetic relationship among the eight known pathogenic races of this fungus. The inferred intraspecific phylogeny shows that each of those races forms a monophyletic lineage. Moreover, virulence of races to resistant chickpea cultivars has been acquired in a simple stepwise pattern, with few parallel gains or losses. Although chickpea cultivars resistant to Fusarium wilt are available, they have not yet been extensively deployed, so that the stepwise acquisition of virulence is still clearly evident.
Jiménez-Gasco
M Mar
MM
Department of Plant Pathology, The Pennsylvania State University, University Park, PA, USA.
Navas-Cortés
Juan A
JA
Jiménez-Díaz
Rafael M
RM
D005075:Biological Evolution; D029863:Cicer / Q000382:microbiology*; D016172:DNA Fingerprinting; D005670:Fusarium / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D005819:Genetic Markers; D014644:Genetic Variation; D020648:Peptide Elongation Factor 1 / Q000145:classification / Q000235:genetics; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D019105:Random Amplified Polymorphic DNA Technique; D014774:Virulence / Q000235:genetics
D005819:Genetic Markers; D020648:Peptide Elongation Factor 1