Wheat (Triticum aestivum L.) is one of the most important staple crops in the world. Wheat was the first domesticated crop and the youngest polyploid species among crops. To meet growing human needs, a new understanding of the structure and function of the wheat genome is needed. However, the wheat genome is large (16,000 Mb) and has a high proportion of repeated sequences (80%), making it a difficult crop for genomics research. In recent years, the availability of large cytogenetic libraries has facilitated research on the wheat genome. Sequencing the wheat genome could enable more rapid genetic improvements and improve human health and nutrition.

CD Genomics is a leading service provider for agricultural genomics research, offering reliable wheat genome sequencing services to support research and breeding efforts in the field of wheat genomics for clients worldwide. Our services help improve yield, disease resistance, and nutritional content of wheat varieties.

Our wheat genome sequencing service

CD Genomics offers comprehensive and customizable wheat genome sequencing services using cutting-edge technology and expertise to characterize the wheat genome at the cytogenetic, genetic, and molecular levels. Our services cover all stages of the sequencing process, from library preparation to data analysis, ensuring high-quality and accurate results.

With our advanced next-generation sequencing and long-read sequencing technology platforms, as well as bioinformatics tools, we can decode wheat genomes at many different polyploidy levels. Our wheat genome sequencing services are designed to address the complexity of the wheat genome and provide researchers with valuable insights into its structure and function.

CD Genomics offers a wide range of wheat genomes and their annotations, including but not limited to:

What we offer

CD Genomics offers bacterial artificial chromosomes (BAC)/C₀t-based cloning and sequencing (CBCS), methylation filtration (MF), high C₀t (HC), or a combination of methods for wheat genome sequencing. The selected BAC method consists of isolating gene-containing BACs by hybridization to ESTs (expressed sequence tags) and constructing a minimum tiling path (MTP) based on the fingerprints. Subsequently, gene-rich MTPs were sequenced. In addition, we used gene filtering techniques such as MF and CBCS/HC to enrich genes in the wheat genome. These methods are cost-effective while maintaining high coverage of gene regions.

We can also obtain molecular maps of bread wheat, emmer wheat, and einkorn wheat using a variety of molecular markers, where gene-rich regions (GRRs) and recombination hotspots can also be identified. Our strategy includes the construction of large insert libraries and the development of large EST collections, genetic and physical molecular mapping, gene targeting systems, TILLING, RNA interference (RNAi), etc.

We aim to provide the scientific community with accurate and timely sequence annotations of the wheat genome and, to facilitate comprehensive analyses of the structure and function of the wheat genome. CD Genomics offers a comprehensive range of wheat genomics research:

• Molecular mapping of the wheat genome
• In situ hybridization studies in wheat
• In situ cloning in wheat
• Gene distribution in wheat: gene-rich and gene-poor regions
• Flow cytogenetics and microdissection of wheat chromosomes
• Spatial sequencing of wheat genes
• Functional genomics
• Comparative genomics
• Epigenetics in Wheat
• Wheat chloroplast and mitochondrial genomes
• Wheat quantitative trait loci (QTL) and protein quantity loci (PQL)
• Wheat genome origin/evolution

Applications of genomics to molecular breeding of wheat

CD Genomics has made a significant contribution to molecular breeding in wheat by providing insights into the genetic basis of important traits and enabling the development of more precise and effective crop improvement strategies.

• Association mapping

Association mapping has been applied to study a variety of traits in wheat, including kernel morphology, milling quality, wheat grain protein content, resistance to rust and powdery mildew, and kernel yield. By identifying significant marker-trait associations, association mapping can help reveal the genetic architecture behind these traits and facilitate targeted breeding efforts.

• Marker-assisted selection (MAS)

MAS has been successfully used to transfer genes for insect and pest resistance, as well as genes associated with improved bread-making and pasta quality, into wheat lines adapted to specific regions.

Case study of wheat genome sequencing

Disease-resistance is a key trait in wheat breeding, and recent breakthroughs in long-read genome sequencing have greatly facilitated the cloning of disease resistance genes. Researchers combined long-read, optical mapping, and chromosome conformation capture techniques to perform a high-quality chromosome-scale assembly of the South African bread wheat (Triticum aestivum) cultivar Kariega. This assembly provided unprecedented continuity and enabled the identification of disease-resistance genes with high precision.

They identified the race-specific disease resistance gene Yr27 (encoding an intracellular immune receptor) as the major contributor to this resistance. Yr27 is allelic to the leaf rust resistance gene Lr13; the Yr27 and Lr13 proteins show 97% sequence identity. This may provide a basis for engineering Yr27 alleles with multiple recognition specificities in wheat.

Fig. 1. Assembly-guided cloning of QYr.sgi-2B.1. (Kishor et al., 2020)

CD Genomics offers cutting-edge wheat genome sequencing services to provide comprehensive genomic information to researchers and breeders for their studies. We aim to provide data to support basic research on the genetics of important wheat traits and to promote wheat improvement. If you are interested, please feel free to contact us.

Reference

1. Athiyannan, Naveenkumar, et al. Long-read genome sequencing of bread wheat facilitates disease resistance gene cloning. Nature genetics. 54.3 (2022): 227-231.