LAUSR

Stripe rust, caused by Puccinia striifomis f. sp. tritici (Pst), is one of the most destructive wheat diseases in China. Understanding the interregional dispersal of Pst inoculum is important for controlling the disease. In the present study, wheat stripe rust samples collected from the winter-spore production and over-summering regions in November 2018 to March 2019 were studied through virulence testing and molecular characterization. From 296 isolates, 96 races were identified using a set of 19 Chinese wheat cultivars and 111 races were identified using 18 Yr single-gene lines as differentials. The isolates from Hubei province in the winter-spore production area had the highest similarity in virulence with those from eastern Yunnan in the oversummering area. Molecular characterization using 13 simple-sequence repeat and 43 Kompetitive allele specific PCR-single nucleotide polymorphism markers supported the conclusion that the Pst populations in the winter-spore production regions were from Guizhou and eastern Yunnan, key over-summering areas in the southwest. Furthermore, the analysis of the wind movement at the 700 hPa high-altitude also supported the conclusion of spore dispersal from the southwestern oversummering region to the southcentral winter-spore production region. The results of this study provide the epidemiological basis for deploying various effective resistance genes in different regions to control stripe rust.