This collection reviews advances in the key areas required to achieve durable disease resistance in cereal crops, from advances in understanding pathogen biology/epidemiology and plant pathogen interactions to identifying sources of resistance and advance techniques for breeding new varieties.
Human population is escalating at an enormous pace and is estimated to reach 9.7 billion by 2050. As a result, there will be an increase in demand for agricultural production by 60–110% between the years 2005 and 2050 at the global level; the number will be even more drastic in the developing world. Pathogens, animals, and weeds are altogether responsible for between 20 to 40 % of global agricultural productivity decrease. As such, managing disease development in plants continues to be a major strategy to ensure adequate food supply for the world. Accordingly, both the public and private sectors are moving to harness the tools and paradigms that promise resistance against pests and diseases. While the next generation of disease resistance research is progressing, maximum disease resistance traits are expected to be polygenic in nature and controlled by selective genes positioned at putative quantitative trait loci (QTLs). It has also been realized that sources of resistance are generally found in wild relatives or cultivars of lesser agronomic significance. However, introgression of disease resistance traits into commercial crop varieties typically involves many generations of backcrossing to transmit a promising genotype. Molecular marker-assisted breeding (MAB) has been found to facilitate the pre-selection of traits even prior to their expression. To date, researchers have utilized disease resistance genes (R-genes) in different crops including cereals, pulses, and oilseeds and other economically important plants, to improve productivity. Interestingly, comparison of different R genes that empower plants to resist an array of pathogens has led to the realization that the proteins encoded by these genes have numerous features in common. The above observation therefore suggests that plants may have co-evolved signal transduction pathways to adopt resistance against a wide range of divergent pathogens. A better understanding of the molecular mechanisms necessary for pathogen identification and a thorough dissection of the cellular responses to biotic stresses will certainly open new vistas for sustainable crop disease management. This book summarizes the recent advances in molecular and genetic techniques that have been successfully applied to impart disease resistance for plants and crops. It integrates the contributions from plant scientists targeting disease resistance mechanisms using molecular, genetic, and genomic approaches. This collection therefore serves as a reference source for scientists, academicians and post graduate students interested in or are actively engaged in dissecting disease resistance in plants using advanced genetic tools.
There is an increasing need for an understanding of the fundamental processes involved in the mechanisms by which disease resistances are introduced into crop plants. This book provides a wide-ranging coverage of the successes and failures of the classical techniques; it describes the advances towards modern technology and addresses the problems of pathogen variation. Crop plants that are considered include: cereals (wheat, barley, rice), potatoes, vegetables and soft fruits.
This book presents deliberations on molecular and genomic mechanisms underlying the interactions of crop plants to the biotic stresses caused by different diseases and pests that are important to develop resistant crop varieties. Knowledge on the advanced genetic and genomic crop improvement strategies including molecular breeding, transgenics, genomic-assisted breeding, and the recently emerging genome editing for developing resistant varieties in cereal crops is imperative for addressing FHNEE (food, health, nutrition, energy, and environment) security. Whole genome sequencing of these crops followed by genotyping-by-sequencing has provided precise information regarding the genes conferring resistance useful for gene discovery, allele mining, and shuttle breeding which in turn opened up the scope for 'designing' crop genomes with resistance to biotic stresses. The eight chapters each dedicated to a cereal crop in this volume elucidate on different types of biotic stresses and their effects on and interaction with the crop; enumerate on the available genetic diversity with regard to biotic stress resistance among available cultivars; illuminate on the potential gene pools for utilization in interspecific gene transfer; present brief on classical genetics of stress resistance and traditional breeding for transferring them to their cultivated counterparts; depict the success stories of genetic engineering for developing biotic stress-resistant crop varieties; discuss on molecular mapping of genes and QTLs underlying stress resistance and their marker-assisted introgression into elite varieties; enunciate on different genomics-aided techniques including genomic selection, allele mining, gene discovery, and gene pyramiding for developing adaptive crop varieties with higher quantity and quality of yields, and also elaborate some case studies on genome editing focusing on specific genes for generating biotic stress-resistant crops.
Genetic and Genomic Resources For Cereals Improvement is the first book to bring together the latest available genetic resources and genomics to facilitate the identification of specific germplasm, trait mapping, and allele mining that are needed to more effectively develop biotic and abiotic-stress-resistant grains. As grain cereals, including rice, wheat, maize, barley, sorghum, and millets constitute the bulk of global diets, both of vegetarian and non-vegetarian, there is a greater need for further genetic improvement, breeding, and plant genetic resources to secure the future food supply. This book is an invaluable resource for researchers, crop biologists, and students working with crop development and the changes in environmental climate that have had significant impact on crop production. It includes the latest information on tactics that ensure that environmentally robust genes and crops resilient to climate change are identified and preserved. - Provides a single-volume resource on the global research work on grain cereals genetics and genomics - Presents information for effectively managing and utilizing the genetic resources of this core food supply source - Includes coverage of rice, wheat, maize, barley, sorghum, and pearl, finger and foxtail millets
Plant diseases and pests are a major constraint to agricultural production despite the various measures used to control them. Chemical control, although often e~~ective, may pose environmental hazards and is relatively expensive, especially in developing countries where it may be completely uneconomic. Control through genetically mediated resistance to diseases and pests, is both cheap and environmentally sa~e and at present most diseases and pests o~ staple ~ood crops are controlled through some form of resistance. One of the basic problems in the use of resistance is its ~re quent lack of durability; very often a type of resistance is used that 'breaks down' after a certain period. The temporary nature of this resistance, due to the development of new strains of pest or pathogen able to overcome it, has seriously hindered the improvement o~ the yield potential of many crops as a continuing effort is needed to replace old cultivars who resistance has failed, with new ones. Following Vanderplank's now classical publications (1963, 1968) which differentiated horizontal and vertical resistance, studies on several host-parasite systems have shown that di~ferent types of resistance can be distinguished genetically and epidemiologically, and on the ability o~ the pests or pathogens to adapt to them. A knowledge of how resistance operates at the population level has also opened up possibilities of 'managing' relatively simple resistance types in such a way that a stable host-pathogen system can be pro duced with a minimum of crop loss.
Assists policymakers in evaluating the appropriate scientific methods for detecting unintended changes in food and assessing the potential for adverse health effects from genetically modified products. In this book, the committee recommended that greater scrutiny should be given to foods containing new compounds or unusual amounts of naturally occurring substances, regardless of the method used to create them. The book offers a framework to guide federal agencies in selecting the route of safety assessment. It identifies and recommends several pre- and post-market approaches to guide the assessment of unintended compositional changes that could result from genetically modified foods and research avenues to fill the knowledge gaps.
Wheat Blast provides systematic and practical information on wheat blast pathology, summarises research progress and discusses future perspectives based on current understanding of the existing issues. The book explores advance technologies that may help in deciding the path for future research and development for better strategies and techniques to manage the wheat blast disease. It equips readers with basic and applied understanding on the identification of disease, its distribution and chances of further spread in new areas, its potential to cause yield losses to wheat, the conditions that favour disease development, disease prediction modelling, resistance breeding methods and management strategies against wheat blast. Features: Provides comprehensive information on wheat blast pathogen and its management under a single umbrella Covers disease identification and diagnostics which will be helpful to check introduction in new areas Discusses methods and protocol to study the different aspects of the disease such as diagnostics, variability, resistance screening, epiphytotic creation etc. Gives deep insight on the past, present and future outlook of wheat blast research progress This book’s chapters are contributed by experts and pioneers in their respective fields and it provides comprehensive insight with updated findings on wheat blast research. It serves as a valuable reference for researchers, policy makers, students, teachers, farmers, seed growers, traders, and other stakeholders dealing with wheat.
From February 24 -28, 1992 an international symposium on Durability of Disease Resistance was held at the International Agricultural Centre in Wageningen, the Netherlands. The symposium, organized by the Department of Plant Breeding of Wageningen Agricultural University and the Centre for Plant Breeding and Repro duction Research, CPRO-DLO, was part of the DGIS funded programme Durable Resistance in Developing Countries. Without any form of prevention or protection nearly all crops will be seriously or even severely damaged by a range of pathogens. In modern agriculture man has been able to control many if not most pathogens using i) pesticides, ii) phyto sanitary methods such as control of seed and plant material in order to start a crop disease free, iii) agronomic measures such as crop rotation, iv) disease resis tance or combinations of these measures. Over the years the use of pesticides has increased enormously and so did the pro blems associated with pesticide use, such as environmental pollution and building of resistance and tolerance to these pesticides in the pathogens. The use of resis tance too increased strongly over the years and here too problems arose.