Genetic Inheritance of Rust Resistance in Pearl Millet [Pennisetum glaucum (L.) R. Br.]: A Study of F₁ F₂, and Backcross Generations across Two Environments.

Rust disease caused by Puccinia substriata var. indica is a major foliar disease affecting pearl millet [Pennisetum glaucum (L.) R. Br.], leading to significant yield losses. The present investigation was undertaken to study the inheritance pattern of rust resistance using six generations (P1, P2, F1, F2, B1, B2) derived from three different crosses involving resistant and susceptible inbred lines. In Cross-I (PM-967 × PM-1035), the segregation of F2 and backcross populations conformed to a 3:1 and 1:1 ratio respectively, indicating monogenic dominant inheritance of rust resistance. Similar results were observed in Cross-II (PM-1035 × PM-1103), where F2 and B2 populations followed expected Mendelian ratios, confirming single gene control of resistance with dominance. The F1s of both crosses exhibited complete resistance, reinforcing the dominance of resistance alleles. Cross-III, involving two resistant lines (PM-1013 × PM1035), further supported the presence of complementary gene action or allelic interactions, though detailed results are pending confirmation. The study concludes that rust resistance in the evaluated crosses is primarily governed by a single dominant gene, which can be effectively utilized in breeding programs for the development of rust-resistant pearl millet hybrids and varieties. These findings offer significant implications for marker-assisted selection and the deployment of durable rust resistance in pearl millet improvement programs.