Jornal de Patologia Vegetal e Microbiologia

Abstrato

Evaluation of Detached Leaf Assay for Assessing Leaf Rust (Puccinia triticina Eriks.) Resistance in Wheat

Anteneh Boydom, Woubit Dawit and Getaneh W/Ab

The use of resistant cultivars is the most economical and effective method to control leaf rust of wheat caused by Puccinia triticina Eriks. Generally screening of wheat germplasm for resistance to rusts is carried out in the greenhouse and field conditions using seedling and adult plants. However, these screening trails are influenced by environmental factors and limit the number of races to be evaluated simultaneously. In the present study, a detached leaf assay was evaluated for screening of wheat germplasm resistance to leaf rust. As treatments, two senescence retardant chemicals (benzimidazole and kinetin) at different concentrations and combinations were added to 5% water-agar. The selected media was further validated in 20 wheat genotypes using three leaf rust races. The media containing 10 mg/L kinetin and 30 mg/L benzimidazole inoculated using an atomizer was the best in delaying the senescence and thereby increasing the sporulation. A positive correlation (r=0.9) between the detached leaf assay and the whole seedling assay infection types was observed. The standard errors for detached leaf and whole seedling assays were 0.24 and 0.3, respectively. The low standard errors further confirm the consistency of the disease response rating between the two assays. Generally this study revealed that the infection types were found to be similar both in detached leaf and whole seedlings assay. Therefore, detached leaf assay can be used to assess wheat genotypes against leaf rust.