Evaluation of Inbreds for Resistance to Post-Flowering Stalk Rot Disease in Maize (Zea mays.)

Abstract

Maize (Zea mays) is the most influential crop in the world, which can grow in temperate as well as tropical conditions. It is a major source for food, livestock, the beverage industry and cosmetics. In recent days maize production decreased drastically due to many diseases. Fusarium stalk rot is one among them. To evaluate the genotypes resistance against PFSR, 40 maize genotypes were subjected against five virulent isolates of Fusarium using the same artificial inoculation method. Varying disease reactions among the inbreds, with some exhibiting premature drying and lodging. After 40 days post-inoculation, internode infection was observed, and disease severity was assessed based on lesion spread within or across internodes. The inbreds were categorized according to their resistance levels, ranging from highly resistant to highly susceptible based on internode infection. Only one inbred showed high resistance to both FUR11 and Raichur isolates. None of the inbreds exhibited high resistance or resistance against the F1 isolate. Eight inbreds showed resistance against multiple isolates. One inbred, DML-1802, displayed high resistance to FUR11 and resistance to Raichur isolate, while another, A8-6, was highly susceptible to all tested isolates, showing infection spreading up to two internodes and observed xylem vessel rotting and hollow stems. Eleven resistant inbreds against Fusarium stalk rot were selected for a breeding program aimed at developing Fusarium stalk rot-resistant hybrids. The identification of variability among Fusarium species causing stalk rot in maize provided valuable insights for future research due to the limited understanding of Fusarium heterogeneity in maize stalk rot.