Integrative Evaluation of Pearl Millet Restorer Lines for Blast Resistance Using Phenotypic Screening and Gene Specific SSR Markers

Pearl millet (Pennisetum glaucum (L.) R. Br.) is a climate-resilient cereal crop cultivated extensively in arid and semi-arid regions, particularly in India and sub-Saharan Africa. Despite its tolerance to harsh abiotic stresses, productivity is limited by an array of biotic factors, especially blast disease caused by Magnaporthe grisea, leading to significant yield losses by affecting leaves, stems and panicles. The present investigation aimed to evaluate 77 diverse pearl millet restorer lines for putative resistance against blast disease by screening under field conditions and employing gene-specific Simple Sequence Repeat (SSR) markers. The field experiment was conducted during the Kharif, 2023 at RVSKVV, Gwalior, in a randomized complete block design with two replications. Blast resistance screening was carried out under natural epiphytotic conditions, and disease severity was rated using a modified 1–9 scale. Among the evaluated restorer lines, 13 genotypes found to be highly resistant, including R-20876, R-23774, R-24665 and R-20212 owing to their negligible blast symptoms. Concurrently, molecular analysis was performed employing 20 SSR markers. Five SSR markers revealed moderate to high polymorphism, with major allele frequency ranging from 0.402 to 0.571, gene diversity from 0.557 to 0.701, and PIC values from 0.479 to 0.646. Marker Xpgird 49 was proved the most informative. Of the 77 genotypes, several exhibited high to moderate resistance, while others ranged between susceptible to highly susceptible. The study highlights the potential of integrating phenotypic and molecular screening to identify resistant and genetically diverse genotypes. These findings can be instrumental in breeding programmes aimed to develop high-yielding, blast-resistant pearl millet cultivars for sustainable agriculture in disease-prone regions.