Wheat Stripe Rust Epidemic and Virulence of Puccinia striiformis f. sp. tritici in China in 2002

Abstract

In China, wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive diseases of wheat and can cause severe yield losses when susceptible cultivars are grown and weather conditions are favorable for the disease. Wheat stripe rust most frequently affects the winter wheat growing areas in Northwest, Southwest, and North China, and the spring wheat growing areas in Northwest China. In the 2001-2002 growing season, a widespread stripe rust epidemic affected about 6.6 million hectares of wheat in 11 provinces: Si-chuan, Chongqing, eastern Gansu, southern and western Shaanxi, southern and central Ningxia, Yunnan, Guizhou, Hubei, Henan, southern and central Hebei, and Shandong. The epidemic could be attributed to relatively warm weather from November 2001 to March 2002, high frequencies of stripe rust races CYR31 and CYR32, and widely grown susceptible cultivars. Race CYR31 was virulent on the Chinese differential cultivars Trigo Eureka, Fulhard, Lutescens 128, Mentana, Virgilio, Abbondanza, Early Premium, Funo, Danish 1, Fengchan 3, Lovrin 13, Shui-yuan 11, Lovrin 10, and Hybrid 46. Race CYR32 had all the virulence factors of CYR31, plus virulences on Chinese differential cultivars Jubilejina 2 and Kangyin 655, i.e., CYR32 was virulent on all differential cultivars, except Zhong 4. When tested on the world and European differential and some other resistant genotypes, CYR32 was virulent on Chinese 166 (Yr1), Heines VII (Yr2, Yr25, and YrHVII), Vilmorin 23 (Yr3a and Yr4a), Heines Kolben (Yr6 and YrHK), Lee (Yr7, Yr22, and Yr23), Clement (Yr9, Yr25, YrCle), VPM1 (Yr17), Selkirk (Yr27), Anza (YrA), Carstens V (YrCV1, YrCV2, and YrCV3), Gaby (YrG), Strubes Dickkopf (Yr25), and Suwon 92/Omar (YrSO). Resistance genes in Triticum spelta album (Yr5), Zhong 4, and Moro (Yr10 and YrMor) were effective against all races identified.

Inheritance and molecular mapping of genes for all-stage resistance to stripe rust in wheat cultivar N. Strampelli

“…According to previous reports (Wan et al 2004;Zhou et al 2005) and our study, Compair was susceptible to most Chinese prevalent Pst races including CYR29-mut3 (IT 3 to 4) in the seedling stage, whereas N. Strampelli was resistant to these races (IT 0 to 2). Therefore, YrN.S-1 and Yr19 should be different.…”

“…Wheat genotypes Compair (Yr8 and Yr19), Druchamp (Yr3a, YrDru, YrDru2), Express (YrExp1 and YrExp2), AVS/6*Yr9 (Yr9), Lovrin 13 (Yr9), and Lemhi (Yr21) (Chen et al 1995(Chen et al , 1996Shi et al 2001;Wan et al 2004;Lin and Chen 2008) were used in molecular markers tests or seedling tests to determine if N. Strampelli and these varieties share a resistance gene(s) on chromosomes 5BL or 1BL.…”

“…Yr9, originally derived from Secale cereale L., and AVS/6*Yr9 and the Chinese differential cultivar Lovrin 13 carry this gene. Both AVS/6*Yr9 and Lovrin 13 were susceptible to CYR29, CYR30, CYR31 and CYR33 (Wan et al 2003(Wan et al , 2004, whereas N. Strampelli was resistant to all of these races in the seedling stage. In wheat genotype Lemhi, gene Yr21 was susceptible to CYR29, CYR30, CYR31, CYR33, Su11-4 and Su11-11(IT 3 to 4), but these races were avirulent to N. Stampelli (IT 0 to 2).…”

“…The effective use of such strategies depends greatly on the availability of a range of resistance genes. The recent appearance and increase in Pst races CYR32 and CYR33 made most commercial and candidate varieties lost their resistances to stripe rust in China (Wan et al 2004;Jia et al 2007). It is, therefore, urgent to identify new stripe rust resistance genes in wheat breeding programs.…”

Monitoring Wheat Stripe Rust Using Remote Sensing Technologies in China

“…The four most destructive epidemics of this disease occurred in 1950, 1964, 1990 and 2002, which caused yield losses up to 6.0, 3.2, 1.8 and 1.3 million metric tons, respectively [15], [16]. Prevention and control of the disease is very important for wheat production and even for food security in China.…”