Yield losses associated with different levels of stripe rust resistance of commercial wheat cultivars in China

Abstract

Wheat stripe rust is one of the most destructive diseases to affect wheat. Although the major resistant wheat varieties have made a great contribution to the global food security, yield losses due to the stripe rust still occurs in the large wheat growing areas when climatic conditions are unstable. Despite this threat, resistance levels and yield losses of these elite wheat cultivars under wheat stripe rust infection have not been well studied. Based on the present investigation of natural infection conditions over two years, analysis of the area under the disease progress curves (AUDPC) differentiated susceptible cultivars Mianmai 367 (MM367) (788.59), Jinmai 47 (JM47) (1087.71), and Avocet Susceptible (AvS) (1314.59) from resistant cultivars Xikemai 18 (XKM18) (177.50) and Xiaoyan 6 (XY6) (545.67). Stripe rust resulted in a two-year mean yield loss of 32% for all tested varieties. The susceptible varieties JM47, AvS, and MM367 lost 64%, 55%, and 21% of grain yield, respectively. On the contrary, rust-resistant cultivars XKM18 and XY6 lost only 11% and 28%, respectively. In addition, stripe rust resulted in reduced kernel hardness (KH), flour yield (FY), and flour whiteness (FW). Dough and gluten properties were also affected. Overall, results revealed that the grain yield and quality loss of the resistant wheat cultivars were less than in the susceptible cultivars. Disease-resistant cultivars such as XKM18 should be promoted and recommended for application. It may also be suggested that growing a susceptible variety such as MM367 could be feasible in combination with fungicide application under high disease pressure.