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Qi A., Li X., Shi L., Liu D., Li Z. (2015): Identification of a leaf rust resistance gene in the Chinese wheat line LB0288. Czech J. Genet. Plant Breed., 51: 43-49.Leaf rust (LR), caused by Puccinia triticina (Pt), is worldwide one of the most spread diseases in common wheat (Triticum aestivum L.). With the objective of identifying and mapping new genes for resistance to leaf rust, F 1 and F 2 plants from a cross between the resistant cultivar LB0288 and the susceptible cultivar Thatcher were inoculated with the Chinese P. triticina pathotype THTT in the greenhouse. A set of 1273 simple sequence repeat (SSR) primer pairs were used to test the parents and the resistant and susceptible bulks. The results indicated, that LB0288 carried a single dominant resistance gene LrLB88, closely linked to the CAPS marker of Lr1 (WR003) and the SSR marker Xbarc144, with genetic distances of 0 cM and 5.3 cM, respectively. Based on the chromosomal location and seedling reactions, it can be concluded that LrLB88 might be a new leaf rust resistance gene. These markers can be useful for marker assisted selection in breeding of leaf rust resistant wheat cultivars.

Wang J., Shi L., Zhu L., Li X., Liu D. (2014): Genetic analysis and molecular mapping of leaf rust resistance genes in the wheat line 5R618. Czech J. Genet. Plant Breed., 50: 262-267.The wheat (Triticum aestivum L.) line 5R618, bred at the China Agricultural University, is resistant in the seedling stage to the majority of the current Chinese pathotypes of wheat leaf rust (Puccinia triticina). To identify and map the leaf rust resistance gene in the 5R618 line, F 2 plants and F 2:3 families from a cross between 5R618 and Zhengzhou5389 (susceptible) were inoculated in the greenhouse with the Chinese P. triticina pathotype THJP. Results from the F 2 and F 2:3 populations indicate that a single dominant gene, temporarily designated Lr5R, conferred resistance. Using the molecular marker method, Lr5R was located on the 3DL chromosome. It was closely linked to the markers Xbarc71 and OPJ-09 with genetic distances of 0.9 cM and 1.0 cM, respectively. At present only one designated gene (Lr24) is located on the 3DL chromosome. The genetic distance between Lr5R and Lr24 confirms that Lr5R is a new leaf rust resistance gene.

Wang J., Li Z., Shi L., Zhu L., Ren Z., Li X., Liu D., Shah S.J.A. (2015): QTL mapping for adult-plant leaf rust resistance genes in Chinese wheat cultivar Weimai 8. Czech J. Genet. Plant Breed., 51: 79-85.The wheat cultivar Weimai 8 is a good source of adult-plant resistance to leaf rust in China. In order to understand the genetic background of the resistance genes, 179 F 2:3 families derived from the cross Weimai 8 and Zhengzhou 5389 (susceptible to leaf rust) were used to construct a linkage map. Results showed that there was a major QTL on chromosome 2AS, temporarily named QLr.hbau-2AS, responsible for the resistance. QLr.hbau-2AS from the resistant parent Weimai 8 was between the SSR markers Xcfd36 and Xbarc1138, with an interval length of 2.58 cM. In the 2010-2011, 2011-2012 and 2012-2013 crop seasons, it explained 25.79, 71.55 and 60.72% of the phenotypic variation, respectively. The location of QLr.hbau-2AS was close to the leaf rust resistance gene Lr37. However, they may not be the same since QLr.hbau-2AS has a different virulence test response from Lr37. This study identified two closely linked flanking molecular markers QLr.hbau-2AS and these molecular markers will help marker-assisted selection in breeding resistant cultivars in the future.

The Chinese wheat line Yu 356-9 exhibits a high level of resistance to leaf rust. In order to decipher the genetic base of resistance in Yu 356-9, gene postulation, inheritance analyses, and chromosome linkage mapping were carried out. Gene postulation completed using 15 leaf rust pathotypes and 36 isogenic lines indicated that Yu 356-9 was resistant to all pathotypes tested. F 1 and F 2 plants from the cross Yu 356-9 (resistant)/Zhengzhou 5389 (susceptible) were tested with leaf rust pathotype "FHNQ" in the greenhouse. Results indicated a 3:1 segregation ratio, indicative of the presence of a single dominant leaf rust resistance gene in Yu 356-9 which was temporarily designated as LrYu. Bulk segregant analysis and molecular marker assays were used to map LrYu. Five SSR markers on chromosome 2BS were found closely linked to LrYu. Among these markers, Xwmc770 is the most closely linked, with a genetic distance of 5.7 cM.