Determining the order of resistance genes against Stagonospora nodorum blotch, Fusarium head blight and stem rust on wheat chromosome arm 3BS.

Background: Stagonospora nodorum blotch (SNB), Fusarium head blight (FHB) and stem rust (SR), caused by the fungi Parastagonospora (synonym Stagonospora) nodorum, Fusarium graminearum and Puccinia graminis, respectively, significantly reduce yield and quality of wheat. Three resistance factors, QSng.sfr-3BS, Fhb1 and Sr2, conferring resistance, respectively, to SNB, FHB and SR, each from a unique donor line, were mapped previously to the short arm of wheat chromosome 3B.

High-density mapping of the major FHB resistance gene Fhb7 derived from Thinopyrum ponticum and its pyramiding with Fhb1 by marker-assisted selection.

Wheat lines with shortened Th. ponticum chromatin carrying Fhb7 and molecular markers linked to Fhb7 will accelerate the transfer of Fhb7 to breeding lines and provide an important resource for future map-based cloning of this gene. Fusarium head blight is a major wheat disease globally.

Obviation of wheat resistance to the Hessian fly through systemic induced susceptibility.

Unlike most documented plant-insect interactions, Hessian fly-resistance [Mayetiola destructor (Say)] in wheat (Triticum aestivum L.) is initiated by a gene-for-gene recognition event in which plants carrying a specific R gene recognize salivary effectors encoded by a corresponding larval avirulence gene. However, dual infestation resulting from oviposition by virulent insects from 5 d before to 3 d after oviposition by avirulent insects on the same host plant, lead to systemic induced susceptibility, obviation of resistance, and ultimately the survival of both virulent and genetically avirulent progeny to adulthood.

A genetic map of Lophopyrum ponticum chromosome 7E, harboring resistance genes to Fusarium head blight and leaf rust.

The leaf rust resistance gene Lr19 and Fusarium head blight (FHB) resistance quantitative trait loci (QTL) derived from the wild wheatgrass Lophopyrum ponticum have been located on chromosome 7E. The main objectives of the present study were to develop a genetic map of chromosome 7E and map the two resistance loci using a population of 237 F(7:8) recombinant inbred lines (RILs) derived from a cross between two Thatcher-L. ponticum substitution lines, K11463 (7el(1)(7D)) and K2620 (7el(2)(7D)).

Transcript profiles of two wheat lipid transfer protein-encoding genes are altered during attack by Hessian fly larvae.

A sequence encoding a putative type-1 lipid transfer protein from wheat (Triticum aestivum L. em Thell) was identified through 'GeneCalling', an mRNA profiling technology. The mRNA for the Hfr-LTP (Hessian fly-responsive lipid transfer protein) gene decreased in abundance (196-fold) in susceptible wheat plants over the first eight days of attack by virulent Hessian fly larvae (Mayetiola destructor Say).

Comparison of genetic and cytogenetic maps of hexaploid wheat (Triticum aestivum L.) using SSR and DArT markers.

A number of technologies are available to increase the abundance of DNA markers and contribute to developing high resolution genetic maps suitable for genetic analysis. The aim of this study was to expand the number of Diversity Array Technology (DArT) markers on the wheat array that can be mapped in the wheat genome, and to determine their chromosomal location with respect to simple sequence repeat (SSR) markers and their position on the cytogenetic map. A total of 749 and 512 individual DArT and SSR markers, respectively, were identified on at least one of four genetic maps derived from recombinant inbred line (RIL) or doubled haploid (DH) populations.

Expression analysis of defense-related genes in wheat in response to infection by Fusarium graminearum.

Fusarium head blight (FHB), caused by the fungi Fusarium graminearum and Fusarium culmorum, is a worldwide disease of wheat (Triticum aestivum L.). The Chinese cultivar Ning 7840 is one of a few wheat cultivars with resistance to FHB.

A novel wheat gene encoding a putative chitin-binding lectin is associated with resistance against Hessian fly.

SUMMARY The gene-for-gene interaction triggering resistance of wheat against first-instar Hessian fly larvae utilizes specialized defence response genes not previously identified in other interactions with pests or pathogens. We characterized the expression of Hfr-3, a novel gene encoding a lectin-like protein with 68-70% identity to the wheat germ agglutinins. Within each of the four predicted chitin-binding hevein domains, the HFR-3 translated protein sequence contained five conserved saccharide-binding amino acids.

Gene-for-gene defense of wheat against the Hessian fly lacks a classical oxidative burst.

Genetic similarities between plant interactions with microbial pathogens and wheat interactions with Hessian fly larvae prompted us to investigate defense and counterdefense mechanisms. Plant oxidative burst, a rapid increase in the levels of active oxygen species (AOS) within the initial 24 h of an interaction with pathogens, commonly is associated with defenses that are triggered by gene-for-gene recognition events similar to those involving wheat and Hessian fly larvae. RNAs encoded by Hessian fly superoxide dismutase (SOD) and catalase (CAT) genes, involved in detoxification of AOS, increased in first-instar larvae during both compatible and incompatible interactions.

A resistance-like gene identified by EST mapping and its association with a QTL controlling Fusarium head blight infection on wheat chromosome 3BS.

Fusarium head blight (FHB) is a major disease in the wheat growing regions of the world. A quantitative trait locus (QTL) on the short arm of chromosome 3B controls much of the variation for resistance. The cloning of candidate disease-resistance genes for FHB QTLs on chromosome 3B can provide further elucidation of the mechanisms that control resistance.

Induction of wheat defense and stress-related genes in response to Fusarium graminearum.

Fusarium head blight (FHB), caused by species of the fungus Fusarium, is a worldwide disease of wheat (Triticum aestivum L.). The Chinese T.