Leaf rust resistance genes in Aegilops genus: occurrence and efficiency

Abstract

Leaf rust is a common and costly wheat disease. The introduction of resistance genes derived from wheat wild relatives is one way to improve disease control. However, due to the rapid development of virulence in the casual pathogen Puccinia triticina, the long-term effectiveness of some leaf rust resistance (Lr) genes is questionable. To assess this, we examined 130 accessions of 13 wheat wild relative species from the Aegilops genus. The presence of 9 Lr genes was determined by PCR using primers complementary to Lr gene markers. The studied individuals were exposed to artificial inoculation with P. triticina under greenhouse and field conditions, respectively. Based on infection rate, the degree of resistance for each individual was estimated. The relationship between the presence of Lr genes and the degree of manifested resistance was assessed using canonical correlation analysis (CCA) and analysis of variance (ANOVA). Our results indicate the effective participation of Lr9 in seedling resistance while Lr58 is involved in adult plant resistance.