Rudolf Appels

The integration of biotechnology concepts and technologies are now accepted as part of an overall strategy in plant breeding as the multidisciplinary approaches that characterize crop improvement enable a holistic systems approach to the study of expression and regulation of genes (and gene networks). Speedy delivery of new genotypes for planting is crucial and marker-assisted selection applications provide more informative diagnostic probes for identifying favorable combinations of alleles in new germplasm. Components of plant yield and grain quality are complex and this article discusses the technical advances in the context of developing plants that can contribute to increased production to address broader issues of climate change and providing food for an increasing world population.

Combinations of genetic variation and the addition of flour from non-wheat sources are discussed as approaches to modifying the processing and health attributes of wheat bread. Natural variation in the major seed proteins (comprising the gluten complex) affecting flour quality has been extremely well characterized and GM approaches have been used to investigate further sources of variation. Variation leading to changes in antigenicity and allergenicity can now be characterized as the responses of humans to the consumption of wheat products are more fully understood. Modern as well as traditional applications of food processing can decrease or increase epitopes in gluten proteins, thus more focus is argued to be required on the identification and details of toxic epitopes associated with specific health problems. In view of the level of gluten sensitivity within a proportion of the human population, the preparation of bread with lower or no gluten is considered to be a priority.

It is ten years since Volume 1 of The World Wheat Book was completed and the intervening years have seen many changes in the world economy, in agriculture in the countries where wheat is grown, and major developments in the techniques of wheat breeding. This second volume therefore updates the first volume by adding to the countries discussed, giving an update on agronomy and cropping practices, and reviewing the technological advances in wheat breeding techniques. The opening chapters summarise the history of wheat growing, the development of wheat breeding, and the current status of breeding in the countries covered. The next set of chapters looks at agronomy and cropping practices in a wide range of wheat growing regions across the world. The third set of chapters records the latest advances in wheat breeding, looking at concepts and strategies as well as current and developing techniques. The fourth set reviews the developing end uses. The final group of chapters examines specific biotic and abiotic threats from viruses, insect pests and diseases. This book is subtitled A History of Wheat Breeding. It would be even more accurate to say that it records and discusses the continuing history of wheat breeding.

Genetic maps are the fundamental tools to identify features of phenotypes that are linked to specific genetic loci and eventually DNA sequences or genes. The major use of genetic linkage maps has, therefore, been to identify quantitative trait loci (QTL). Genetic maps are also essential for marker-assisted selection, comparative mapping, high-resolution mapping and map-based cloning. To date, over 40 maps with at least 300 markers have been published for different Triticeae populations. The quality of genetic maps can be affected by a number of factors and map curation ensures that map quality issues are identified and, where possible, resolved. We report on the issues involved in the production of quality genetic linkage maps by inspection of marker genotype data after map construction. A number of technologies, which have been developed to complement the genetic linkage maps of the Triticeae such as radiation induced deletion mutations, optical mapping and HAPPY mapping, are discussed. We also report on the construction of consensus maps and the issues involved in the building of these. Genetic map quality, including the ordering of loci within linkage groups, is of great importance for robust QTL detection and a number of QTL mapping methods are discussed in relation to features of the genetic map used in the analysis. Finally, we describe high-resolution mapping, which is used to improve the confidence interval for a QTL and to obtain markers closer to the trait of interest.

The quality attributes of cereal grains are valued in the context of a complex food chain that integrates outputs achievable by breeding, production, and processing. New processing technologies, environmental change, and changes in consumer preferences demand that quality attributes of wheat and barley need to be continually modified. The advances in the genomics of quality described in this chapter provide the basis for ensuring that the genetic approaches encompassing the complexities of the gene networks underpinning quality attributes can meet the challenges presented by the rapid changes occurring within the food chain.

When genomic research first came on the scene, much of the biomedical research community viewed it as a limited venture with limited potential. We now know that such an assessment was both highly premature and wonderfully inaccurate. In the last ten years, we’ve witnessed such remarkable acceleration in the merger of basic and applied genomic research that, among other things, genomic research is now thought of as being intrinsic to current drug research. Through rigorous comparative analysis, the genomes of cold-blooded vertebrate, avian, and other mammalian species are providing a deeper understanding of the human genome. Moreover, genomic sequences, which are becoming available for several species have proven to be highly relevant to drug research with regard to a number of otherwise intractable conditions.

Marker Assisted Selection (MAS) is being applied to a large breeding program that makes approximately 3,000 crosses and has a field program of 180,000 plots across 14 sites each year. In the breeding program MAS is seen as complementing the existing screening for yield, quality and disease resistance. This paper describes the experiences of applying MAS, role of MAS in the breeding program, its effect on breeding methodology, and future directions for MAS in the program