Evaluation of leaf rust resistance in selected bread wheat accessions from the National Plant Gene Bank of Iran

The prevalence of wheat leaf rust has increased in recent years due to global climate change conditions. The disease spreads in warm and humid areas in the north and south regions of Iran, causing damage to the susceptible cultivars. Plant germplasms in each country hold rich reserves of resistance genes that influence biotic and abiotic stress. In this study, 100 germplasms of Iranian bread wheat which had previously shown resistance to stem rust, 10 cultivars commonly grown in Iran and two susceptible cultivars, Bolani and Morocco, were selected for greenhouse and field experiments. Greenhouse experiments were conducted to evaluate the performance of a pure isolate from the northern region of the country. The greenhouse experiment followed a completely randomized design, while the field experiment was conducted on the Iraqi-Mahalleh farm in Golestan province using an augmented experimental design. The Bolani and Morocco cultivars showed over 90% infection in the field and 4 scales in the greenhouse. The results indicate that 24.7% of the accessions and cultivars were resistant in both the greenhouse and the field. In addition, 38.1% of the accessions and cultivars were susceptible in the greenhouse but resistant in the field. Conversely, 2.9% were resistant in the greenhouse but, susceptible in the field. Finally, 34.3% exhibited susceptibility in both the greenhouse and the field. The wheat germplasms that were resistant in both conditions and those showing susceptibility in the greenhouse but, resistance in the field were selected for further investigations in developing resistant cultivars.