Influence of post-infection temperature on three components of partial resistance in wheat to wheat leaf rust

Abstract

Three components of partial resistance (PR) were studied at three post-infection temperatures using seven spring wheat genotypes differing in level of PR and two different wheat leaf rust races. The components were latency period (LP), infection frequency (IF) and urediosorus size (US). The expression of LP was more sensitive to temperature than the expression of the other two components. LP-prolonging genes were better expressed at low temperatures than at high temperatures and cultivar differences tended to increase with decreasing temperature in both seedling and adult plant stages. The reaction of IF to temperature differed from that of LP and US, probably because IF is regulated by another mechanism than LP and US.