Evaluation of Biofortified Provitamin a Maize Genotypes for Resistance to Fusarium Ear Rot Caused by Fusarium verticillioides

Abstract

Provitamin A (PVA) maize was developed to combat vitamin A deficiency in developing regions. However, Fusarium ear rot threatens grain yield, quality, and safety, potentially limiting the intended benefits. A screenhouse evaluation was conducted at the Institute of Agricultural Research and Training, Moor Plantation, Ibadan, Nigeria, to determine the responses of PVA maize genotypes to Fusarium verticillioides. Nineteen PVA maize genotypes were evaluated under artificial inoculation using a completely randomised design with three replicates. Maize ears were artificially inoculated using the silk-channel method with 2 mL of spore suspension (1.0 × 106 spores mL-1). Disease severity (DS) was assessed at physiological maturity using a 1–7 rating scale. Agronomic, yield, and disease severity data were subjected to analysis of variance. Significant (p < 0.01) genotypic differences were observed for disease severity, which ranged from 1.00 to 5.00. Genotype 17A16494-PVASYHGBC2 exhibited the highest level of resistance (DS = 1.00), whereas 16C25335-F2TWLY131211 was the most susceptible (DS = 5.00). Notably, 14A21616-DOMINANT-YELLOW-VARIETY combined low disease severity (DS = 1.33) with superior ear weight (89.03 g) and cob weight (59.77 g), indicating the potential to combine resistance with desirable agronomic performance. Based on disease severity ratings, 31.58% of the genotypes were resistant, 36.84% were moderately resistant, 21.05% were moderately susceptible, 5.26% were susceptible, and 5.26% were highly susceptible. The study identified several genotypes as promising sources of resistance for the development of high-yielding, Fusarium ear rot-resistant PVA maize cultivars for tropical environments.