Abstract

Fusarium head blight is one of the most important diseases on maize production in Burkina Faso. It affects both yields and production quality, due to toxins that are dangerous to human and animal health. The effectiveness of control measures for this disease depends on a better understanding of the intra-population variability of the pathogens responsible, as well as control of their pathogenicity. The aim of this study was to contribute to the reinforcement of control measures for the pathogens responsible for Fusarium head blight in maize through a better understanding of morphological and pathogenic variability. A two-factor factorial design was used to conduct the study. According to our results, analysis of variance based on qualitative and quantitative characteristics revealed significant differences (P < 0.0001) between isolates for each characteristic studied, indicating the existence of variability within isolates. Principal Component Analysis showed that radial growth, conidial concentration, number of bands and edge condition were the main variables reflecting variability between isolates. This variability was further materialized by the results of the Hierarchical Ascending Classification defining five distinct classes. As for the pathogenicity of the isolates, the results indicate that isolates I14, I18 and I20 isolated respectively from SR21, eWARI, and Espoir seeds were the most virulent because they caused more damage to the most susceptible lines (VL0511298, PI547090, and PI601191) according to the severity scale used. On the other hand, the resistant lines (FBML10, ELN41-1-1-4, and ELN45-1-1-1) showed scores ranging from zero to two. These results will be used as a basic for a better understanding of the diversity of Fusarium verticillioides in Burkina Faso in order to develop more effective means of controlling this disease. In addition, the pathogenic isolates could be used as fungal reference material for various research programs on F. verticillioides of maize.

Key words: Fusarium verticillioides, Zea mays L., differential lines, Burkina Faso.