Heritability of durable resistance to stripe rust in bread wheat ( <i>Triticum aestivum</i> L.)

Wheat yellow (stripe) rust is one of the most destructive diseases worldwide. Growing resistant cultivars is the most economical and eco-friendly method to control the disease. To determine heritability and gene number of durable resistance to stripe rust, four Egyptian wheat cultivars were crossed to four genotypes; Jupateco 73R, Opata 85, Anza, and Pavon 76 carrying the durable resistant genes were studied to enhance wheat yellow rust durable resistance. The genetic analysis has been done based on F₁, and F₂ of crosses, and our findings confirmed the di-genic and tri-genic control to this disease. The result from the F₂ population showed that Misr2/Opata and Giza168/Anza were segregated fitting the expected ratios of 57 resistant: 7 susceptible. The segregation ratios of resistance and susceptibility of F₂ plants showed tri-genic hereditary of yellow rust resistance, permitting the following conclusions about the genes expressed in adult plants suggesting a difference of three dominant genes between the parental cultivars. The cross Giza168/Pavon76 was showed phenotypic ratios fitted the theoretical ratios, 63 resistant: 1 susceptible, suggesting difference of two dominant and one recessive gene for resistance. These genotypes are very important for wheat breeding to stripe rust resistance in Egypt.