QTL analysis of native Fusarium head blight and deoxynivalenol resistance in 'D8006W'/'Superior', soft white winter wheat population.

Background: Fusarium head blight (FHB), caused by Fusarium graminearum, is a major disease of wheat in North America. FHB infection causes fusarium damaged kernels (FDKs), accumulation of deoxynivalenol (DON) in the grain, and a reduction in quality and grain yield. Inheritance of FHB resistance is complex and involves multiple genes.

Identification of Fusarium head blight sources of resistance and associated QTLs in historical and modern Canadian spring wheat.

Fusarium head blight (FHB) is one the most globally destructive fungal diseases in wheat and other small grains, causing a reduction in grain yield by 10-70%. The present study was conducted in a panel of historical and modern Canadian spring wheat ( L.) varieties and lines to identify new sources of FHB resistance and map associated quantitative trait loci (QTLs).

Evaluation of Genomic Prediction for Fusarium Head Blight Resistance with a Multi-Parental Population.

Fusarium head blight (FHB) resistance is quantitatively inherited, controlled by multiple minor effect genes, and highly affected by the interaction of genotype and environment. This makes genomic selection (GS) that uses genome-wide molecular marker data to predict the genetic breeding value as a promising approach to select superior lines with better resistance. However, various factors can affect accuracies of GS and better understanding how these factors affect GS accuracies could ensure the success of applying GS to improve FHB resistance in wheat.

Genetic Characterization of Multiple Components Contributing to Fusarium Head Blight Resistance of FL62R1, a Canadian Bread Wheat Developed Using Systemic Breeding.

Fusarium head blight (FHB) is a devastating fungal disease of small-grain cereals that results in severe yield and quality losses. FHB resistance is controlled by resistance components including incidence, field severity, visual rating index, Fusarium damaged kernels (FDKs), and the accumulation of the mycotoxin deoxynivalenol (DON). Resistance conferred by each of these components is partial and must be combined to achieve resistance sufficient to protect wheat from yield losses.

A phenylpropanoid diglyceride associates with the leaf rust resistance Lr34res gene in wheat.

The gene Lr34res is one of the most long-lasting sources of quantitative fungal resistance in wheat. It is shown to be effective against leaf, stem, and stripe rusts, as well as powdery mildew and spot blotch. Recent biochemical characterizations of the encoded ABC transporter have outlined a number of allocrites, including phospholipids and abscisic acid, consistent with the established general promiscuity of ABC transporters, but ultimately leaving its mechanism of rust resistance unclear.

Genetic Analysis of Domestication Parallels in Annual and Perennial Sunflowers ( spp.): Routes to Crop Development.

Parallels exist between the domestication of new species and the improvement of various crops through selection on traits which favor the sowing, harvest and retention of yield potential and the directed efforts to improve their agronomics, disease resistance and quality characteristics. Common selection pressures may result in the parallel selection of orthologs underlying these traits and homologies between crop species can be exploited by plant breeders to improve germplasm. Perennial grains and oilseeds are a class of proposed crops for improving the diversity and sustainability of agricultural systems.

Genetic analyses of native Fusarium head blight resistance in two spring wheat populations identifies QTL near the B1, Ppd-D1, Rht-1, Vrn-1, Fhb1, Fhb2, and Fhb5 loci.

QTL analyses of two bi-parental mapping populations with AC Barrie as a parent revealed numerous FHB-resistance QTL unique to each population and uncovered novel variation near Fhb1. Fusarium head blight (FHB) is a destructive disease of wheat worldwide, leading to severe yield and quality losses. The genetic basis of native FHB resistance was examined in two populations: a recombinant inbred line population from the cross Cutler/AC Barrie and a doubled haploid (DH) population from the cross AC Barrie/Reeder.

Genetic Characterization of Leaf and Stripe Rust Resistance in the Brazilian Wheat Cultivar Toropi.

Leaf and stripe rust are major threats to wheat production worldwide. The effective, multiple rust resistances present in the Brazilian cultivar Toropi makes it an excellent choice for a genetic study of rust resistance. Testing of DNA from different seed lots of Toropi with 2,194 polymorphic 90K iSelect single nucleotide polymorphism markers identified significant genetic divergence, with as much as 35% dissimilarity between seed lots.

Genetic factors affecting Fusarium head blight resistance improvement from introgression of exotic Sumai 3 alleles (including Fhb1, Fhb2, and Fhb5) in hard red spring wheat.

Background: Fusarium head blight resistance genes, Fhb1 (for Type-II resistance), Fhb2 (Type-II), and Fhb5 (Type-I plus some Type-II), which originate from Sumai 3, are among the most important that confer resistance in hexaploid wheat. Near-isogenic lines (NILs), in the CDC Alsask (susceptible; n = 32) and CDC Go (moderately susceptible; n = 38) backgrounds, carrying these genes in all possible combinations were developed using flanking microsatellite markers and evaluated for their response to FHB and deoxynivalenol (DON) accumulation in eight environments. NILs were haplotyped with wheat 90 K iSelect assay to elucidate the genomic composition and confirm alleles' presence.

Mapping the A Genome for QTL Conditioning Resistance to Fusarium Head Blight in a Wheat Population with Triticum timopheevii Background.

Development and use of resistant wheat cultivars is the most practical and economical approach for the control of Fusarium head blight (FHB). In the present study, a population of recombinant inbred lines derived from the cross between 'AC Brio' (a Canadian bread wheat cultivar moderately susceptible to FHB) and 'TC 67' (an FHB-resistant cultivar derived from Triticum timopheevii) was used to map quantitative trait loci (QTL) for FHB resistance using microsatellite molecular markers. Multiple interval mapping detected several QTL for FHB resistance on the chromosomes 5AL and 6A.

Fusarium Head Blight Resistance QTL in the Spring Wheat Cross Kenyon/86ISMN 2137.

Fusarium head blight (FHB), caused by , is a very important disease of wheat globally. Damage caused by includes reduced grain yield, reduced grain functional quality, and results in the presence of the trichothecene mycotoxin deoxynivalenol in Fusarium-damaged kernels. The development of FHB resistant wheat cultivars is an important component of integrated management.

Analysis of deoxynivalenol and deoxynivalenol-3-glucosides content in Canadian spring wheat cultivars inoculated with Fusarium graminearum.

Contamination of wheat grains with Fusarium mycotoxins and their modified forms is an important issue in wheat industry. The objective of this study was to analyse the deoxynivalenol (DON) and deoxynivalenol-3-glucosides (D3G) content in Canadian spring wheat cultivars grown in two locations, inoculated with a mixture of 3-acetyldeoxynivalenol (3-ADON)-producing Fusarium graminearum strains and a mixture of 15-acetlyldeoxynivalenol (15-ADON)-producing F. graminearum strains.

Inheritance of Leaf Rust and Stripe Rust Resistance in the Brazilian Wheat Cultivar 'Toropi'.

Leaf rust (Puccinia triticina) and stripe rust (P. striiformis f. tritici) affect wheat production worldwide.

Transcriptional coordination and abscisic acid mediated regulation of sucrose transport and sucrose-to-starch metabolism related genes during grain filling in wheat (Triticum aestivum L.).

Combining physiological, molecular and biochemical approaches, this study investigated the transcriptional coordination and abscisic acid (ABA) mediated regulation of genes involved in sucrose import and its conversion to starch during grain filling in wheat. Sucrose import appears to be mediated by seed localized TaSUT1, mainly TaSUT1D, while sucrose cleavage by TaSuSy2. Temporal overlapping of the transcriptional activation of AGPL1 and AGPS1a that encode AGPase with that of the above genes suggests their significance in the synthesis of ADP-glucose; TaAGPL1A and TaAGPL1D contributing the majority of AGPL1 transcripts.

Molecular characterization and sequence diversity of genes encoding the large subunit of the ADP-glucose pyrophosphorylase in wheat (Triticum aestivum L.).

The large subunit of ADP glucose pyrophosphorylase (AGPase), the rate limiting enzyme in starch biosynthesis in Triticum aestivum L., is encoded by the ADP glucose pyrophosphorylase large subunit (AGP-L) gene. This was the first report on the development of three genome-specific primer sets for isolating the complete genomic sequence of all three homoeologous AGP-L genes on group 1 chromosomes.

Isolation and characterization of rubisco small subunit gene promoter from common wheat (Triticum aestivum L.).

Choice of an appropriate promoter is critical to express target genes in intended tissues and developmental stages. However, promoters capable of directing gene expression in specific tissues and stages are not well characterized in monocot species. To identify such a promoter in wheat, this study isolated a partial sequence of the wheat small subunit of RuBisCO (TarbcS) promoter.

Transcriptome profiling of wheat differentially expressed genes exposed to different chemotypes of Fusarium graminearum.

The study is an overview of the behavior of the wheat transcriptome to the Fusarium graminearum fungus using two different chemotypes. The transcriptome profiles of seven putative differentially expressed defense-related genes were identified by SSH and further examined using qPCR. Fusarium head blight (FHB) of wheat (Triticum aestivum L.

Identification and characterization of the three homeologues of a new sucrose transporter in hexaploid wheat (Triticum aestivum L.).

Background: Sucrose transporters (SUTs) play important roles in regulating the translocation of assimilates from source to sink tissues. Identification and characterization of new SUTs in economically important crops such as wheat provide insights into their role in determining seed yield. To date, however, only one SUT of wheat has been reported and functionally characterized.

Identification of novel QTL for resistance to Fusarium head blight in a tetraploid wheat population.

Most tetraploid durum wheat (Triticum turgidum L var. durum) cultivars are susceptible to Fusarium head blight (FHB). This study reports novel quantitative trait loci (QTL) associated with FHB resistance.

Construction and characterization of a cDNA library from wheat infected with Fusarium graminearum Fg 2.

Total RNA from wheat spikes infected with F. graminearum Fg2 was extracted and the mRNA was purified. Switching Mechanism at 5' end of the RNA Transcript (SMART) technique and CDS Ill/3' primer were used for first-strand cDNA synthesis using reverse transcriptase by RT-PCR.

Development of genome-specific primers for homoeologous genes in allopolyploid species: the waxy and starch synthase II genes in allohexaploid wheat (Triticum aestivum L.) as examples.

Background: In allopolypoid crops, homoeologous genes in different genomes exhibit a very high sequence similarity, especially in the coding regions of genes. This makes it difficult to design genome-specific primers to amplify individual genes from different genomes. Development of genome-specific primers for agronomically important genes in allopolypoid crops is very important and useful not only for the study of sequence diversity and association mapping of genes in natural populations, but also for the development of gene-based functional markers for marker-assisted breeding.

Identification of a hybridization window that facilitates sizeable reductions of pollen-mediated gene flow in spring wheat.

Transgenic wheat (Triticum aestivum L.) with improved agronomic traits is currently being field-tested. Gene flow in space is well-documented, but isolation in time has not received comparable attention.

Varietal and chromosome 2H locus-specific frost tolerance in reproductive tissues of barley (Hordeum vulgare L.) detected using a frost simulation chamber.

Exposure of flowering cereal crops to frost can cause sterility and grain damage, resulting in significant losses. However, efforts to breed for improved low temperature tolerance in reproductive tissues (LTR tolerance) has been hampered by the variable nature of natural frost events and the confounding effects of heading time on frost-induced damage in these tissues. Here, we establish conditions for detection of LTR tolerance in barley under reproducible simulated frost conditions in a custom-built frost chamber.