Cereals are the major sources of calories worldwide. Their production should be high to achieve food security, despite the projected increase in global population. Genomics research may enhance cereal productivity. Genomics immensely benefits from robust next-generation sequencing (NGS) techniques, which produce vast amounts of sequence data in a time and cost-efficient way. Research has demonstrated that gene sequences among closely related species that share common ancestry have remained well conserved over millions of years of evolution. Comparative genomics allows for comparison of genome sequences across different species, with the implication that genomes with large sizes can be investigated using closely related species with smaller genomes. This offers prospects of studying genes in a single species and, in turn, gaining information on their functions in other related species. Comparative genomics is expected to provide invaluable information on the control of gene function in complex cereal genomes, and also in designing molecular markers across related species. This chapter discusses advances in sequencing technologies, their application in cereal genomics and their potential contribution to the understanding of the relationships between the different cereal genomes and their phenotypes.
Part of the book: Plant Genomics
In bread wheat (Triticum aestivum L.), flowering time and plant stature are important phenological and agronomic traits for adaptation, yield potential, and yield stability. Timely flowering is critical for production, and the flowering window has to be late enough to avoid early season frosts but early enough to avoid late season stresses such as heat and terminal drought. Flowering time is controlled mainly by vernalization, photoperiod response, and earliness per se genes, which can be exploited to fine‐tune growth and tailor flowering time for the production of desirable wheat cultivars. Tailoring flowering time could help reduce preharvest sprouting problems by escaping high temperatures and late season rainfall, which promote preharvest sprouting, hence yield loss. Concisely summarizing available information on flowering time and identifying research gaps could provide direction for future research. This chapter, therefore, discusses: (i) the progress made in discovering genes involved and the impact of their extensive allelic variation on flowering time, (ii) the potential benefits of tailoring wheat's flowering time to improve yield, and (iii) the benefits of introgressing genes for other complimentary traits, such as semidwarf and preharvest sprouting resistance on advanced lines to achieve higher yield, thus, sustainable food security.
Part of the book: Wheat Improvement, Management and Utilization
Wheat (Triticum aestivum L.) houses a wide range of nutritional components such as iron (Fe), zinc (Zn), vitamins and phenolic acids, which are important for plant metabolism and human health. The bioavailability of these nutritional components is low due to their interaction with other components and low quantity in the endosperm. Biofortification is a more sustainable approach that could improve the bioavailability of essential nutritional components. Substantial progress has been made to improve nutritional quality through the application of conventional, technological and transgenic approaches. This has led to the discovery, cloning and introgression of the Gpc-B1 gene; the invention of online databases with minimally characterized biosynthetic, metabolic pathways and biological processes of wheat-related species; the establishment of genetic variation in grain Fe and Zn content and the biofortification of wheat with Zn by the HarvestPlus organization. Nonetheless, the biofortification of wheat with micronutrients and phenolic acids is still a challenge due to incomplete understanding of the wheat genome, biosynthesis and translocation of selected nutritional components into different wheat grain compartments. There is a need to integrate selected omics technologies to obtain a holistic overview and manipulate key biological processes involved in the remobilization and biosynthesis of nutritional components into desired wheat grain compartments.
Part of the book: Wheat Improvement, Management and Utilization