Morphometric Analysis of Populations of Fusarium oxysporum f.sp. vasinfectum (Atk.) Snyder & Hansen, the Causal Agent of Cotton Fusarium Wilt in Côte d’Ivoire

Abstract

Cotton plays a crucial role in the socio-economic development of communities within its production regions. However, it is susceptible to numerous pathogens that cause significant yield losses. Among these, Fusarium vascular wilt of cotton, caused by Fusarium oxysporum f.sp. vasinfectum Snyder & Hansen (Fov) stands out as one of the most destructive and threatening diseases in Côte d’Ivoire. Extensive research efforts have been devoted to Fov to identify effective control strategies against this fungus . This study focuses on a morphometric analysis of Fov populations collected throughout the Ivorian cotton basin to characterize their diversity. On Potato dextrose agar (PDA) medium, the isolates exhibited three distinct mycelial appearances: 1) Cottony and dense; 2) Cottony and short; 3) Fine and short. Also, the five colony colorations were observed: 1) Purple; 2) Lavender; 3) Salmon; 4) Pink; 5) White. Furthermore, the composition of the culture medium was found to significantly influence both mycelial growth and sporulation of the isolates. The results indicate that the pathogen demonstrated the ability to grow and sporulate on both complex and synthetic media, but to varying extents. PDA medium proved more conducive to sporulation, whereas CDA medium favored mycelial growth. The results of this study reveal significant phenotypic variability in mycelial appearance and colony coloration among Fov isolates. They also suggest that the nutritional requirements for mycelial growth and sporulation, two critical aspects of fungal development, differ substantially.