Inheritance of rust resistance in cultivated groundnut (Arachis hypogaea L.)

The present investigation was carried out to study the mode of inheritance of rust (Puccinia arachidis Speg.) resistance in groundnut (Arachis hypogaea L.). Crosses were made between a susceptible (GPBD-5) and three resistant genotypes (GPBD-4, ICGV86699 and ICGV99005). Susceptibility to rust of F₁’s in all the three crosses indicated that susceptibility was dominant over resistance. Resistant F₂ plants were further crossed to GPBD-5. The second cycle F₂ populations segregated into susceptible and resistant categories. The observed frequency of plants in each F₂ fitted well into expected ratio of 1 resistant and 3 susceptible with non-significant chi-square values at 5% level indicating that rust resistance in groundnut is determined by a single recessive gene. The F₂ results were confirmed by genetic analysis in F₃ generation.