This proceedings is a collection of 46 selected papers that were presented at the 12th International Wheat Genetics Symposium (IWGS). Since the launch of the wheat genome sequencing project in 2005, the arrival of draft genome sequences has marked a new era in wheat genetics and genomics, catalyzing rapid advancement in the field. This book provides a comprehensive review of the forefront of wheat research, across various important topics such as germplasm and genetic diversity, cytogenetics and allopolyploid evolution, genome sequencing, structural and functional genomics, gene function and molecular biology, biotic stress, abiotic stress, grain quality, and classical and molecular breeding. Following an introduction, 9 parts of the book are dedicated to each of these topics. A final, 11th part entitled “Toward Sustainable Wheat Production” contains 7 excellent papers that were presented in the 12th IWGS Special Session supported by the OECD. With rapid population growth and radical climate changes, the world faces a global food crisis and is in need of another Green Revolution to boost yields of wheat and other widely grown staple crops. Although this book focuses on wheat, many of the newly developed techniques and results presented here can be applied to other plant species with large and complex genomes. As such, this volume is highly recommended for all students and researchers in wheat sciences and related plant sciences and for those who are interested in stable food production and food security.

Drought is the main constraint in common bean (Phaseolus vulgaris) production. Although breeding efforts to increase drought resistance have shown gains in productivity, their full potential remains untapped. Improvements have been limited by the complexity of the trait involved, limited germplasm recombination, and most importantly, the poorly understood genetic basis of tolerance. To gain information about the genetics and mechanism(s) of drought adaptation, I explored the genetic diversity of wild and domesticated Mesoamerican gene pool of the species through genetic analyses in natural, bi-parental, and multi-parental populations. In the first chapter, I evaluated root and shoot traits in a large panel of wild accessions and reference domesticated cultivars, both from the Mesoamerican distribution of common bean, in a greenhouse tube experiment. The domesticated beans were, in general, more vigorous and deeper-rooted than wild beans. Nevertheless, some wild beans were outstanding in their productivity and rooting capacity. A comparison of the measured phenotypic traits with the climatic and soil characteristics of the location of origin of the individual wild bean accessions showed that most traits were significantly associated with mean annual temperature and aridity. The most deeply rooted and productive accessions originated from the driest regions. Each wild accession was genotyped with both a SNP array and a GBS platform; three populations of wild bean accessions were identified, of which the most productive, deeply rooted, and more drought-tolerant population, originating from Central and North-West Mexico and Oaxaca. Through genome-wide association analyses, genomic regions associated with productivity, root depth, and drought adaptation were identified. Some co-located with regions showing signals of selection suggesting that drought stress is a driver of local adaptation in wild common beans.In the second chapter, I investigated the effects of drought stress on the genetic architecture of photosynthate allocation and remobilization in pods, one of the main mechanisms of drought resistance and overall productivity. A bi-parental recombinant inbred line (RIL) population of the Mesoamerican gene pool was evaluated in field conditions under well-watered conditions and terminal and intermittent drought stress in two years. There was a significant effect of the water regime and year on pod harvest index (PHI), a measure of the partition of seed biomass to pod biomass, its components, phenology and grain yield at the phenotypic and QTL level. QTLs for pod harvest index, including a major, stable QTL on chromosome Pv07 was detected. For grain yield, the QTLs were not stable; however, three were detected for the overall mean across environments. There was differential co-localization of the components of PHI, co-localizing mainly with either the pod wall, seed mass, or both. Three of the eight yield QTLs co-localized with PHI QTLs, underlying the importance of photosynthate remobilization in productivity. Epistasis explained a considerable part of the variation, especially for PHI and yield. In the third chapter, to further test the value of wild variation as compared with the domesticated forms, joint linkage mapping of nested populations was carried out in three newly develop domesticated by wild backcrossed recombinant inbred line populations. The populations were developed by crossing three wild accessions representing the extreme range of rainfall of the Mesoamerican wild bean distribution to an elite drought resistant domesticated parent. Grain yield was evaluated under field conditions in two fully irrigated trials in two seasons and a simulated terminal drought in the second season. The highest yielding populations were the populations from the lower part of the rainfall distribution. The populations were genotyped and a consensus map was developed containing 721 SNP markers. Twenty QTLs were found in 13 unique regions on eight chromosomes. At least one wild allele with a significant positive additive effect was found in five of these regions. The additive effects of all the QTLs ranged from -164 to 277 kg ha−1, with some evidence of allelic series. The variation explained by these QTLs ranged from 0.6 to 5.4 % of the total variation. These results underlie the potential of wild variation for bean crop improvement as well the identification of regions for efficient marker-assisted introgression and candidate genes.

This anchor volume to the series Managing Global Genetic Resources examines the structure that underlies efforts to preserve genetic material, including the worldwide network of genetic collections; the role of biotechnology; and a host of issues that surround management and use. Among the topics explored are in situ versus ex situ conservation, management of very large collections of genetic material, problems of quarantine, the controversy over ownership or copyright of genetic material, and more.

Researchers in the field of ecological genomics aim to determine how a genome or a population of genomes interacts with its environment across ecological and evolutionary timescales. Ecological genomics is trans-disciplinary by nature. Ecologists have turned to genomics to be able to elucidate the mechanistic bases of the biodiversity their research tries to understand. Genomicists have turned to ecology in order to better explain the functional cellular and molecular variation they observed in their model organisms. We provide an advanced-level book that covers this recent research and proposes future development for this field. A synthesis of the field of ecological genomics emerges from this volume. Ecological Genomics covers a wide array of organisms (microbes, plants and animals) in order to be able to identify central concepts that motivate and derive from recent investigations in different branches of the tree of life. Ecological Genomics covers 3 fields of research that have most benefited from the recent technological and conceptual developments in the field of ecological genomics: the study of life-history evolution and its impact of genome architectures; the study of the genomic bases of phenotypic plasticity and the study of the genomic bases of adaptation and speciation.

Exploring plant genetic resources is crucial in a time when food security has been a critical topic worldwide due to crop shortages and the impact of climate change. This new book, Plant Genetic Resources for the 21st Century: The OMICS Era, presents the practical advancements in genomics, epigenetics, metabolomics, and phenomics from the point of view of researchers and scientists working in the field of genebanks, genetics resources, and germplasm for enabling plant breeding and adaptation to a changing climate. The book highlights the importance of genebanks as centers of innovation for crop and forage improvement and discusses database solutions for genebanks and germplasm collections. The book first looks at plant genetic resources and their values and goes on to investigate several genomic technologies for plant improvement, conservation, and better adaptation to changing climates. Major crops such as wheat and barley are discussed with genomic approaches for diversity and resilience to drought and other adverse conditions. Other omics techniques discussed include phenomics for the improvement of crop adaptation, metabolomics research for germplasm improvement and adaptation, and more. This volume will be valuable for researchers who are presently working in or with genebanks and genetic resources, primarily for trait or allele discovery and germplasm improvement. Most chapters in the book can also be used as teaching material at the undergraduate and postgraduate levels.