Saturation and comparative mapping of the genomic region harboring Hessian fly resistance gene H26 in wheat

Abstract

Resistance gene H26, derived from Aegilops tauschii Coss., is one of the most eVective R genes against the Hessian Xy [Mayetiola destructor (Say)], an important pest of wheat (Triticum aestivum L.). Using a limited number of PCR-based molecular markers a previous study mapped H26 to the wheat chromosomal deletion bin 3DL3-0.81-1.00. The objectives of this study were to saturate the chromosomal region harboring H26 with newly developed PCR-based markers and to investigate the collinearity of this wheat chromosomal region with rice (Oryza sativa L.) and Brachypodium distachyon genome. A population of 96 F 2 individuals segregating at the H26 gene locus was used for saturation mapping. All wheat ESTs assigned to the deletion bin 3DL3-0.81-1.00 were used to design STS (sequence tagged site) primers. The wheat ESTs mapped near H26 were further used to BLAST rice and B. distachyon genomic sequences for comparative mapping. To date, 26 newly developed STS markers have been mapped to the chromosomal region spanning the H26 locus. Two of them were mapped 1.0 cM away from the H26 locus. Comparative analysis identiWed genomic regions on rice chromosome 1 and Brachypodium Super contig 13 which are collinear with the genomic region spanning the H26 locus within the distal region of 3DL. The newly developed STS markers closely linked to H26 will be useful for mappedbased cloning of H26 and marker-assisted selection of this gene in wheat breeding. The results will also enhance understanding of this chromosomal region which contains several other Hessian Xy resistance genes.

Identification of a novel gene, H34, in wheat using recombinant inbred lines and single nucleotide polymorphism markers

“…In this study, we used a RIL population instead of F 2 as reported in most previous studies (Dweikat et al 2002;Martín-Sánchez et al 2003;Kong et al 2005Kong et al , 2008Liu et al 2005bLiu et al , 2005cYu et al 2009) to improve phenotyping accuracy. RILs have a high recombination frequency resulting from multiple meiotic events that occurred during repeated selfing (Jansen 2003), and a high level of homozygosity that enables replicated phenotyping across different environments.…”

“…All HFR genes from the D genome were derived from Ae. tauschii, the D genome donor of common wheat (Martin et al 1982;Gill et al 1986Gill et al , 1991aRaupp et al 1993;Cox and Hatchett 1994;Ratcliffe and Hatchett 1997;Sardesai et al 2005), and located on chromosomes 1D, 3D, 4D, and 6D (Gill et al 1987;Raupp et al 1993;Cox and Hatchett 1994;Martín-Sánchez et al 2003;Liu et al 2005;Sardesai et al 2005;Wang et al 2006;Zhao et al 2006;Yu et al 2009;Yu et al 2010). In addition to these HFR genes identified from wheat, H21 and H25 were derived from rye (Secale cereale) and transferred to common wheat (Friebe et al 1996).…”

“…Molecular markers closely linked to these genes are essential for such gene pyramiding, however, many earlier reported genes were located to chromosomes using monosomic analysis (Gallun and Patterson 1977;Ohm et al 1995). Some were mapped using DNA markers, but the mapping populations used were mainly F 2 generations (Williams et al 2003;Liu et al 2005a;Liu et al 2005c;Wang et al 2006;Kong et al 2008;Yu et al 2009;Miranda et al 2010). Because only a single plant was phenotyped without replication, escape of infestation may cause significant errors in phenotypic data.…”

Development of a diagnostic co-dominant marker for stem rust resistance gene Sr47 introgressed from Aegilops speltoides into durum wheat

“…After the polymorphic STS markers were identified, they were analyzed on the four BC 2 F 1 plants (0406, 0439, 0696 and 0735) and their derived 36 BC 2 F 3 individuals, along with Rusty, DAS15, and three CS nulli-tetrasomic lines N2AT2D, N2BT2A, and N2DT2A. The polymerase chain reaction (PCR) amplification was carried out as described by Yu et al (2009). The PCR products were electrophoresed on 6 % polyacrylamide gels and stained with Gel-Red, then scanned with a Typhoon 9410 imager (GE Healthcare, Waukesha, WI, USA).…”

Using Sex Pheromone Trapping to Explore Threats to Wheat From Hessian Fly (Diptera: Cecidomyiidae) in the Upper Great Plains

“…The H gene that is chosen for the region is the one for which there is the least virulence within populations. Only a few H genes provide this all-inclusive resistance, for example, the H26 gene discovered in an ancestor of wheat, Aegilops tauschii (Cosson) (Cox et al 1994, Yu et al 2009). Stacking R genes also is expected to provide durable resistance but it requires reliable molecular markers, such as those for H9, H13, H18, H26, and H32 (Dweikat et al 1997;Liu et al 2005;Wang et al 2006;Yu et al 2009Yu et al , 2010.…”