Abstract:

【Objective】 In order to clarify resistance levels and existing Yr genes among 59 wheat cultivars (lines) from the Pacific Northwest (PNW) of the United States, to provide resistance resources for genetic improvement of wheat stripe rust resistance in China. 【Method】 The 59 PNW wheat cultivars (lines) were infected by 3 mixed races of predominant Chinese stripe rust races CRY31, CRY32 and CRY33 to evaluate their resistance at seedling and adult plant stages, and screened with molecular markers tightly linked to currently effective all-stage resistance genes Yr10, Yr15 and adult plant resistance genes Yr18, Yr39. 【Result】Of 59 PNW cultivars (lines), five cultivars (lines) Expresso, 02W50076, ACS52610, WA008012 and WA008018 are all-stage resistance, showing resistance to mixed races of CRY31, CRY32 and CRY33 at both seedling and adult plant stages. 33 cultivars (lines) are adult plant resistance, only showing resistance to stripe rust at adult stage. Based on the molecular screening, none of the 59 PNW cultivars (lines) had the polymorphic bands of lingked markers to Yr10. There are 12, 33 and 29 cultivars (lines) had polymorphic bands of lingked markers to Yr15, Yr18 and Yr39, making up 20%, 56% and 49% of the 59 PNW cultivars (lines), respectively.【Conclusion】All these results suggested that Yr18 and Yr39 were widespread among PNW cultivars (cultivars) and can be utilized in Chinese wheat stripe rust resistance breeding.

Key words: American wheat cultivar')">American wheat cultivar, yellow rust, molecular marker, resistance identification