Fusarium suttonianum Identified as the Causal Agent of Root Rot in Plukenetia volubilis in Peru

Abstract

Sacha inchi (<i>Plukenetia volubilis</i>) is a high-value crop due to its high content of omega-3 fatty acids and its outstanding nutritional, pharmaceutical, and cosmetic properties. However, this species faces challenges from diseases, particularly root rot. In this study, we identified one of the causal agents of root rot in sacha inchi using morphological observations, molecular methods, and pathogenicity tests. The pathogen was isolated from root tissues showing symptoms of <i>Fusarium</i> infection, observed in a plot in the Picota province. Morphological identification, DNA sequencing, and phylogenetic analysis using the <i>ITS</i> and <i>TEF-1α</i> markers revealed that the isolate causing root rot was <i>Fusarium suttonianum</i> (FSSC 20). Analysis of the PQ636870 (<i>ITS</i>) and PQ639345 (<i>TEF-1α</i>) sequences in the NCBI database, together with phylogenetic analysis, revealed 99.58% and 99.51% similarity with the <i>ITS</i> and <i>TEF</i> sequences, respectively, corresponding to <i>F. suttonianum</i>. Pathogenicity tests confirmed that this species induced the same symptoms observed in the field, fulfilling Koch's postulates. This study represents the first report of <i>F. suttonianum</i> as a pathogen causing root rot in sacha inchi in Peru. This finding is critical for developing effective strategies for disease management and control, contributing to the sustainability and improvement of sacha inchi production in the region.