A combination of resistance genes confers high and durable resistance against stripe rust in wheat cultivar Lantian 26

Lantian 26, a leading elite winter wheat cultivar in Gansu Province since its release in 2010, exhibits high resistance or immunization to stripe rust in adult-plant stage under a high disease pressure in Longnan (southeastern Gansu). Identifying the resistance genes in Lantian 26 could provide a basis for enhanced durability and high levels of resistance in wheat cultivars. Here, a segregating population was developed from a cross between a highly susceptible wheat cv. Mingxian 169 and the highly stripe rust-resistant cv. Lantian 26. The F2 and F2:3 progenies of the cross were inoculated with multiple prevalent virulent races of stripe rust for adult plant-stage resistance evaluation in two different environments. Exon sequence alignment analysis revealed that a stripe rust resistance gene on the 718.4-721.2 Mb region of chromosome 7BL, tentatively named as YrLT26, and a co-segregation STS marker GY17 was developed and validated using the F2:3 population and 103 wheat cultivars. The other two resistance genes, Yr9 and Yr30, were also identified in Lantian 26 using molecular markers. Therefore, the key to high and durable resistance to stripe rust at adult stage is the combination of Yr9, Yr30 and YrLT26 genes in Lantian 26. This could be a considerable strategy for improving the wheat cultivars with effective and durable resistance in the high-pressure region for stripe rust.