Identification of sources of resistance to post-flowering stalk rot in short duration maize (Zea mays L.) inbred lines with temperate background

Abstract

Post-Flowering Stalk Rot (PFSR) is a major disease limiting maize (Zea mays L.) production, especially under moisture stress and high planting density. The disease, predominantly caused by Macrophomina phaseolina and Fusarium verticillioides, leads to stalk lodging, premature senescence, and significant yield losses. Developing resistant cultivars is a critical approach to managing this disease. In the present study, 37 short-duration maize inbred lines with temperate background were evaluated for resistance to PFSR under artificial epiphytotic conditions using the standardized toothpick inoculation method. Disease severity was assessed at physiological maturity using a 1-9 rating scale. Out of 37 genotypes, 7 lines including KDMB-134, KDMB-143, KDMB-212, KDMB-412, KDMB-93-1, KDMB-225, and KDMB-20264 were classified as resistant lines (score ≤ 3.0). Twenty two lines showed moderate resistance (score 3.1-5.0), while 8 lines were moderately to highly susceptible. Significant variability in disease response was observed, indicating a strong genetic basis for resistance. The identified resistant lines can serve as valuable donors in breeding programs aimed at developing stalk rot-tolerant hybrids. These findings provide a foundation for future genetic dissection, QTL mapping, and resistance breeding against PFSR in maize.