Detection of Germplasm Accessions and SSR Markers for Rust Resistance in Zoysiagrass (Zoysia japonica Steud.).

Zoysiagrass rust, caused by Puccinia zoysiae Diet., is one of the most important diseases of zoysiagrass and affecting turf quality. Therefore, resistance to rust is a major goal in zoysiagrass breeding programs. In this study, we evaluated six zoysiagrass populations and total of 162 accessions collected from Liaoning, Shandong and Anhui Provinces by field assessment and glasshouse inoculation evaluation. Out of the 162 accessions, 9 accessions (5.6%) were high resistant and 17 accessions (10.5%) were moderate resistant, whereas, 100 accessions (61.7%) were moderate susceptible and 33 accessions (20.4%) were high susceptible. Totally, 67 SSR markers, i.e. 35 from wheat (Triticum aestivum L.), 12 from barley(Hordeum vulgare L.) and 20 from perennial ryegrass(Lolium perenne L.)linked with rust resistance genes were tested on 4 accessions to identify transferability. A total of 35 markers amplified clear SSR type bands, the transfer rates of wheat, barley and perennial ryegrass rust resistance linked SSR markers to zoysiagrass were 34.3%, 50% and 85%, respectively. The SSRs of perennial ryegrass are higher conservative in zoysiagrass than that of wheat and barley. Twenty eight markers of 35 working primer pairs amplified polymorphic bands, and three markers including LpSSRH01A07, LpSSR059 and Xgwm533 consistently produced contrasting bands with fragment size ranging from 200 to 350 bp between rust resistant and susceptible accessions. According to the publications of Dumsday et al. (2003), Schejbel et al. (2007) and Hayden et al. (2004), both LpSSRH01A07 and LpSSR059 markers showed association with crown rust (caused by P. coronata f. sp. lolii) resistance of perennial ryegrass; Xgwm533 marker associated with stem rust (caused by P. graminis f. sp. Tritici) resistant gene Sr2 of wheat. The identified markers linked to rust resistance have the potential for use in marker-assisted breeding in zoysiagrass.