Molecular and Pathogenic Characterization of Fusarium redolens, a New Causal Agent of Fusarium Yellows in Chickpea

The association of Fusarium redolens with wilting-like symptoms in chickpea in Lebanon, Morocco, Pakistan, and Spain is reported for the first time, together with the molecular and pathogenic characterization of isolates of the pathogen from chickpea of diverse geographic origin. Maximum parsimony analysis of sequences of the translation elongation factor la (TEF-1 alpha) gene grouped all E redolens isolates from chickpea in the same main clade. Pathogenicity assays using three chickpea cultivars and isolates from different geographic origins indicated that E redolens is mildly virulent on chickpea. Moreover, infection of chickpea by E redolens induces a disease syndrome similar to that caused by the yellowing pathotype of F oxysporum f. sp. ciceris, including leaf yellowing and necrosis that develop upward from the stem base, and premature senescence of the plant. In contrast, F. redolens does not cause discoloration of the vascular tissues in chickpea but does cause brown necrotic lesions in the tap root and necrosis of lateral roots. F. redolens is not easily differentiated from E oxysporum f. sp. ciceris using morphology-based diagnosis, and the two species cause similar symptoms on chickpea; therefore, the use of molecular protocols should help to avoid misdiagnoses of Fusarium yellows in chickpea.