ROLE OF RESISTANCE (YRS) GENES TO PUCCINIA STRIIFORMIS IN FIVE BREAD WHEAT CULTIVARS SUSCEPTIBLE AND VALIDATION BY MOLECULAR MARKERS IN ASSESSMENT OF RESISTANCE

Wheat stripe rust, caused byPuccinia striiformis f. sp. tritici, is one ofthe most destructive diseases of wheat in the world. Emergence of new race ofthe pathogen in Egypt at last decades, spread of those races pose effect at to
wheat production in Egypt, has required assemblage of a broad genetic base ofresistance. Five ten crosses betweenYr5, Yr10 and Yr15 and each of Sids 12,Sids 13, Gemmeiza 10, Gemmeiza 11, and Sakha 93, were performed. Results
indicated that the five varieties parents exhibited high susceptible reactionagainst stripe rust at seedling and adult stage, on the other hand monogeniclines exhibited high resistance. While crosses against stripe rust at seedling
and adult stages proved that plant segregationF1 plants of the five tencrosses havingYr5, Yr10 and Yr15, were resistant and exhibited low stripe rustreaction (0 - 0, and 1) at seedling stage and low stripe rust severity ranged
between(0, 10R and 10MR ) at adult stage. The result ofF2 plants reactionexhibited wide range of stripe rust reaction (0 to 9) at seedling stage andseverity ranged between (0 to 80S) at adult stage but the direction was in the
side resistance and this confirmed the results of F1. This result confirmed thepresence of resistant gene in thesegregations of the resulted crosses andverified that a single dominant pair gene controls stripe rust resistance at adultstages. Resistance gene of the F2 was expression performance to resistancegenes toYr 5, Yr 10 and Yr 15, those tolerant to yellow rust introgressive linescould be widely used as donors of stability in practical selection of bread wheat.Using the molecular marker method,Yr10 In this study, we used the primer
Xpsp3000 to identify markers linked to yellow rust resistance genes. In thisrespect, specific DNA segment of 52 individual of F2 have linked with primerXpsp3000 260-bp band. The rest 18 individuals did not linked with the primer
Xpsp3000. Segregation in F2 of individual which, reacted with the primerYrSTS/7, 8 and shown in this respect, specific DNA segment of 58 individual ofF2 have linked with primer YrSTS/7, 8 439-bp band. The rest 21 individuals did
not link with the primer YrSTS/7, 8. These markers provide an important tool toplant breeders for marker-aided wheat breeding and also for pyramidingresistance genes in the absence of distinguishable rust virulence's