Stripe rust (incited by Puccinia striiformis f. sp. tritici) is airborne wheat (Triticum aestivum L.) disease with dynamic virulence evolution. Thus, anticipatory and continued screening in hotspot regions is crucial to identify new pathotypes and integrate new resistance resources to prevent potential disease epidemics. A global wheat panel consisting of 882 landraces and 912 improved accessions was evaluated in two locations in Egypt during 2016 and 2017. Five prevalent and aggressive pathotypes of stripe rust were used to inoculate the accessions during the two growing seasons and two locations under field conditions. The objectives were to evaluate the panel for stripe rust resistance at the adult plant stage, identify potentially novel QTLs associated with stripe rust resistance, and validate previously reported stripe rust QTLs under the Egyptian conditions. The results indicated that 42 landraces and 140 improved accessions were resistant to stripe rust. Moreover, 24 SNPs were associated with stripe rust resistance and were within 18 wheat functional genes. Four of these genes were involved in several plant defense mechanisms. The number of favorable alleles, based upon the associated SNPs, was significant and negatively correlated with stripe rust resistance score, i.e., as the number of resistances alleles increased the observed resistance increased. In conclusion, generating new stripe rust phenotypic information on this panel while using the publicly available molecular marker data, contributed to identifying potentially novel QTLs associated with stripe rust and validated 17 of the previously reported QTLs in one of the global hotspots for stripe rust.

Leaf rust caused by Puccinia triticina Eriks., is one of the most common diseases of wheat (Triticum aestivum L.) in Egypt and worldwide. To investigate the population genetic structure of the causal pathogen, 468 single isolates were obtained from 193 samples collected from 12 Egyptian governorates and analyzed during 2016/17 and 2017/18 growing seasons. A total of 125 and 101 leaf rust pathotypes were designated during 2016/17 and 2017/18 growing seasons. The most frequent pathotype was STTTK (9.81% frequency), followed by race PTTNS (2.80% frequency) during 2016/17. While, pathotype PTTTT was occurred at a high frequency (12.16% frequency), followed by the four pathotypes; TTTBT, PTTGS, TTTTT and PTTCT (5.88, 5.10, 5.10 and 4.31%, respectively), during 2017/18. Pathotype STTTK is the most geographically distributed as it was detected in nine governorates in 2016/17, but in 2017/18, PTTTT is the most geographically distributed pathotype, where it was found in seven governorates. High similarity was found between leaf rust populations in the five locations, i.e. Domiatta, Sohag, Alexandria, Kafr El-Sheikh and Bani Sweif, during 2016/17 growing season. Also, high similarity was found between leaf rust pathogen populations of Kafr

Stem rust, caused by Puccinia graminis f. sp. tritici is an important disease of wheat worldwide. To estimate grain yield losses due to stem rust, replicated experiments including twelve wheat cultivars i.e.  Gemmeiza 7, Gemmeiza 9, Gemmeiza 10, Gemmeiza 11, Sakha 61, Sakha 93, Sakha 94, Sids 12, Sids 13, Giza 168, Misr 1 and Misr 2 were evaluated for adult plant resistance at Sakha Research Station, Kafr El-Sheikh, Egypt during 2011/12 and 2012/13 growing seasons. The field experiment was surrounded by spreader area of highly susceptible varieties i.e. Morroco and Max inoculated with a mixture of stem rust races as a source of inoculum. Disease severity was recorded each 10 days and area under disease progress curve (AUDPC) was estimated and ranged from 100 to 475 in 2011/12 and 100 to 750 in 2012/13. It was found that, yield losses ranged between 2.47 % in the wheat cultivar Misr 2 to 6.29 % in the wheat cultivar Sids 12 during 2011/12, while during 2012/13 ranged from 1.96 % in the wheat cultivar Gemmeiza 7 to      8.21 % in the wheat cultivar Misr 1. High correlation was found between yield losses with disease severity and AUDPC.

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