Peanut rust (Puccinia arachidis Speg.) disease: its background and recent accomplishments towards disease resistance breeding.

The peanut rust disease is an economically important biotic stress that significantly reduces the pod and fodder yield and oil quality. It is caused by the basidiomycete fungus Puccinia arachidis Speg. which belongs to class Pucciniomycetes like other rust fungus but has fewer occurrences in teliospore form. The P. arachidis predominantly spreads by the repeated cycle of uredospores in the field. The disease is prevalent in most of the countries where peanut is cultivated and favored by warm and humid climatic conditions. Despite its economic importance, very limited work has been carried out on host-fungus interaction, fungal genetic diversity, and physiological specialization. The present review describes different aspects of P. arachidis especially its symptomatology, cell biological aspects of pathogenesis, epidemiology, and physiology of resistance as well as developments on genetics and genomics of host resistance, and resistance breeding. The review will help to understand the behavior of this causal organism and the host resistance and subsequently design the breeding approaches to check the spread of the disease.