Introgression of leaf rust and stripe rust resistance from Sharon goatgrass (Aegilops sharonensis Eig) into bread wheat (Triticum aestivum L.)

Leaf rust and stripe rust are devastating wheat diseases, causing significant yield losses in many regions of the world. The use of resistant varieties is the most efficient way to protect wheat crops from these diseases. Sharon goatgrass (Aegilops sharonensis or AES), which is a diploid wild relative of wheat, exhibits a high frequency of leaf and stripe rust resistance. We used the resistant AES accession TH548 and induced homoeologous recombination by the ph1b allele to obtain resistant wheat recombinant lines carrying AES chromosome segments in the genetic background of the spring wheat cultivar Galil. The gametocidal effect from AES was overcome by using an “anti-gametocidal” wheat mutant. These recombinant lines were found resistant to highly virulent races of the leaf and stripe rust pathogens in Israel and the United States. Molecular DArT analysis of the different recombinant lines revealed different lengths of AES segments on wheat chromosome 6B, which indicates the location of both resistance genes

European virulence survey for leaf rust in wheat

With standardised near isogenic line (NIL) differentials co-operators were able to present the first comprehensive virulence survey of the European wheat leaf rust population (1996-1999). The work included pathotype identification of 2608 isolates and field tests of NILs. Lr9 and Lr19 were very effective all over Europe. Lr24, Lr25, and Lr28 were also effective, but in some countries and locations substantial virulence frequencies were observed. In addition, the genes Lr12, Lr13, Lr22a, Lr34, Lr35 and Lr37 were effective at the adult plant stage, but locally less so. In general, the indoor seedling tests and adult plant field tests showed good agreement. Virulence to Lr1, Lr2a, Lr24, Lr25, Lr28 and Lr29 tended to increase in the period, for the other Lr-genes the virulence frequency remained more or less stable. Among the 105 pathotypes identified none was clearly predominant in Europe