Wheat (Triticum aestivum L.) is the most widely grown and consumed cereal food crop over all the world as well as Egypt. Stripe or yellow rust, caused by Puccinia striiformis f. sp. tritici, is an important wheat disease and causes considerable yield losses in wheat growing areas worldwide (Shahin et al., 2020).

Most of the widely cultivated wheat cultivars in Egypt possess low levels of adult plant resistance (APR) to stripe rust, due to the sudden occurrence of new aggressive races of wheat stripe rust pathogen in Egypt (Shahin 2002).

Releasing new high yielding and stress resistant wheat cultivars is the main goal of the national breeding program. Biotic and abiotic stresses are becoming more and more challenges to wheat production in current circumstances due to narrow genetic base and climate changes.

The objective of this study was to examine the efficiency of incorporating the four stripe rust resistance genes Yr5, Yr10, Yr15 and YrSp in improving resistance of the two susceptible bread wheat cultivars Sids12 and Gemmeiza11