Development of an international standard set of barley differential genotypes for Pyrenophora teres f. teres

Abstract

International comparison of virulence profiles of Pyrenophora teres f . teres (Ptt), the cause of barley net blotch, is seriously restricted by inconsistencies in differential testers used among researchers. This paper reports an attempt to develop an appropriate set of differentials to standardize characterization of Ptt populations globally. Fourteen barley genotypes (Canadian Lake Shore (CLS), Harbin, c-8755, c-20019, Manchurian, Tifang, CI 9825, CI 5791, CI 9819, Beecher, CI 9214, Skiff, Prior and Corvette) were selected from among genotypes previously used as Ptt differentials. Three cultivars (Pirkka, Haruna Nijo and Harrington) were included to identify a universally susceptible control. Genotypes were inoculated with approximately 1000 Ptt isolates from Russia, Europe, Australia and Canada. The mean reaction frequency of genotypes ranged from highly resistant (CI 9819, CI 5791, c-8755 and CI 9825) to highly susceptible (Harrington, Haruna Nijo and Pirkka). The best differential abilities were demonstrated by Harbin, CLS, c-20019, Manchurian and Prior. Application of cluster analyses identified genotypes with similar reaction patterns, which supported a reduction of genotypes in the set. When combined with an algorithm comparing the ability of individual genotypes to discriminate among Ptt isolates, a further reduction of genotypes was justified. A new, concise set of barley genotypes for differentiating virulences in Ptt was formulated. It is proposed that these genotypes be adopted as the standard, international differential set to characterize and identify the virulence properties of Ptt populations across environments. The new Ptt differential set consists of the genotypes c-8755, c-20019, CI 5791, CI 9825, CLS, Harbin, Prior, Skiff and Harrington.

Pathogenicity Spectra and Screening for Resistance in Barley Against Tunisian Pyrenophora teres f. teres

“…1), the least virulent isolates (pathotype 18), and 20 other isolates that exhibited specific virulence to die differendal CI09214, the most resistant cultivar in the current study ( Fig. The resistance of this cultivar has also been confirmed in other studies (3,12,17,24). The resistance of this cultivar has also been confirmed in other studies (3,12,17,24).…”

“…High pathogenic variability in P. teres f. teres has also been reported from Ausd-alia, New Zealand, Russia, and Canada-countries outside the possible centers of origin of barley diversity (3,12,24,57). High pathogenic variability in P. teres f. teres has also been reported from Ausd-alia, New Zealand, Russia, and Canada-countries outside the possible centers of origin of barley diversity (3,12,24,57).…”

Virulence of MoroccanPyrenophora teresf.teresRevealed by International Differential Barley Genotypes

“…Among them, Canadian Lake Shore CI2750, Tifang CI4407-1, Manchurian M-CI2330, Manchurian CI5791, Manchurian CI1251, Harbin CI4929, CIho4922, CIho5822, Atlas CI4118, Rojo CI5401, Coast CI2235, and Ming CI4797 haven been reported and used as the International Differential set previously (Afanasenko et al 2007;Afanasenko et al 2009). Seed of the international differential set was obtained from Genetic Resource Unit of ICARDA.…”

“…As farmers do not use fungicides on barley in Morocco, the use of resistant cultivars is, therefore the most, cost effective and environmentally friendly disease management strategy. In the past, the variation in virulence of P. teres populations were investigated using sets of differential genotypes (Khan 1982;Bockelman et al 1983;Robinson and Jalli 1996;Yan and Falk 2002;Afanasenko et al 2009), but there is a lack of a universal differential set for the net blotch disease. The aim of this study is to characterize the responses of 16 barley genotypes (International Differential set for Ptt including Moroccan genotypes) to 15 Moroccan isolates of Ptt in order to determine the virulence spectrum of this pathogen in Morocco.…”

Sexual reproduction and soil tillage effects on virulence of Pyrenophora teres in Finland

“…Lai et al (2007) identified three major avirulence genes in P. teres f. teres involved in avirulence/virulence of the fungus: AvrHar, AvrPra1 and AvrPra2, and Beattie et al (2007) identified six amplified fragment length polymorphism (AFLP) markers linked to a P. teres f. teres avirulence gene AvrHeartland. Various methods are used to monitor the host-pathogen interaction and the avirulence/virulence of P. teres f. teres isolates, including the detached leaf method (Afanasenko et al, 2009) and the greenhousebased seedling test using either a Tekauz (1985) scale or percentage of leaf area damaged (Robinson & Jalli, 1996).…”