Heritability of durable resistance to stripe rust in bread wheat (Triticum aestivum 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.