Trait synonyms: Fungal disease resistance, Leaf Rust (Puccinia arachidis Speg)

Peanut leaf rust is caused by Puccinia arachidis. The synonym terms used for this fungus are Bullaria arachidis (Speg.) Arthur & Mains, (1922) and Uromyces arachidis Henn., (1896) [Wikipedia as Source]. The term rust is used for both the disease and the causative fungus (Sillero et al., 2006).

The disease symptoms can be recognized by the appearance of orange pustules on the lower surface of the leaves. The rupturing of these pustules expose masses of reddish brown urediniospores which leads to the spread of infection to the neighboring plants. In highly susceptible genotypes, secondary pustules might surround the original pustules. Later, pustules may form on the upper surface corresponding to the position on the lower surface of leaf. These pustules develop on all the plant parts except flowers. Pustules are usually circular in shape that ranges from 0.5 to 1.4mm in diameter. Rust infection lead to dried and necrotic leaves which stay intact with the plant. The disease is usually spread through urediniospores by air, infected crop debris like surface contaminated pods, seeds or dried leaves. However, spread through seed borne pathogen or germplasm exchange is not evident. Leaf rust can cause infection to plants at any development age. Also, warm and humid weather can facilitate the spread of this fungus. Under favorable circumstances, leaf rust can spread to the entire field and can cause desiccation of all the plants. Early season rust infection may lead to significant yield losses as compared to late season rust epidemics (Sillero et al., 2006;Rashid & Bernier, 1991). In essence, severe disease infection can lead to approximately 50% of the yield losses.