Evaluation of Inbred Lines for Yield and Resistance to Post-Flowering Stalk Rot Disease in Maize (Zea mays L.)

Abstract

Background: Post-Flowering Stalk Rot (PFSR) is a devastating disease of maize caused by a complex of fungal pathogens, predominantly Macrophomina phaseolina in India, especially under prolonged dry conditions. Developing high-yielding and PFSR-resistant inbred lines offers a sustainable and cost-effective strategy for disease management. Aims: The study aims to identify maize inbred lines exhibiting resistance to Macrophomina phaseolina and superior grain yield performance under both artificially inoculated and uninoculated conditions. Methods: The study evaluated sixty-two maize inbred lines for resistance and yield performance under artificially inoculated and uninoculated environments using a randomized block design with three replications at the Maize Research Centre, Hyderabad, during the 2020 kharif season. The fungal isolates of Macrophomina phaseolina used for artificial inoculation were procured from the Plant Pathology Division, Agricultural Research Institute, Rajendranagar, Hyderabad. Disease severity was rated on a 1–9 scale through stem-splitting assessment. Results: The highest yield was recorded by PFSR-95, reflecting its superior genetic potential under normal conditions. In contrast, under inoculated conditions, the inbred lines exhibited a mean yield of 56.7 g per plant, ranging from 20 g (Z-63-45) to 95 g (PFSR-95), highlighting a considerable decline in yield due to disease pressure. The comparison of grain yield performance of maize inbred lines under both environments revealed that the inbred lines viz., MGC-9, MGC-93, MGC-15, MGC-82, PFSR-151, PFSR-46, PFSR-95 and GP-265 showed higher yield level over the check hybrid DHM-117 under uninoculated conditions. While under inoculated conditions, PFSR-95 and PFSR-90 showed superior yield over the check DHM-117, showing their resilience under biotic stress. Conclusion: The study concluded that PFSR-90 and PFSR-95 exhibited strong resistance coupled with superior grain yield over the check DHM-117, while PFSR-95 showed superior yield performance across both environments. These resistant inbred lines serve as valuable genetic resources for breeding high-yielding and PFSR-resistant maize hybrids, contributing to sustainable maize production under stress-prone environments.