Deals with the historical perspectives and the current status of doubled haploid production along with its practical implications in basic and applied research. It highlights various haploid production methods with a comprehensive discussion on their pros and cons, bottlenecks, and embryogenic pathways. The review also describes in detail the results of molecular and genomic studies conducted to investigate the underlying principles of this spectacular technique that has changed the status of many species from recalcitrant to responsive over the last ninety years.
The importance of haploids is well known to geneticists and plant breeders. The discovery of anther-derived haploid Datura plants in 1964 initiated great excitement in the plant breeding and genetics communities as it offered shortcuts in producing highly desirable homozygous plants. Unfortunately, the expected revolution was slow to materialise due to problems in extending methods to other species, including genotypic dependence, recalcitrance, slow development of tissue culture technologies and a lack of knowledge of the underlying processes. Recent years have witnessed great strides in the research and application of haploids in higher plants. After a lull in activities, drivers for the resurgence have been: (1) development of effective tissue culture protocols, (2) identification of genes c- trolling embryogenesis, and (3) large scale and wide spread commercial up-take in plant breeding and plant biotechnology arenas. The first major international symposium on “Haploids in Higher Plants” took place in Guelph, Canada in 1974. At that time there was much excitement about the potential benefits, but in his opening address Sir Ralph Riley offered the following words of caution: “I believe that it is quite likely that haploid research will contr- ute cultivars to agriculture in several crops in the future. However, the more extreme claims of the enthusiasts for haploid breeding must be treated with proper caution. Plant breeding is subject from time to time to sweeping claims from ent- siastic proponents of new procedures.
This book is open access under a CC BY 4.0 license. By 2050, human population is expected to reach 9.7 billion. The demand for increased food production needs to be met from ever reducing resources of land, water and other environmental constraints. Rice remains the staple food source for a majority of the global populations, but especially in Asia where ninety percent of rice is grown and consumed. Climate change continues to impose abiotic and biotic stresses that curtail rice quality and yields. Researchers have been challenged to provide innovative solutions to maintain, or even increase, rice production. Amongst them, the ‘green super rice’ breeding strategy has been successful for leading the development and release of multiple abiotic and biotic stress tolerant rice varieties. Recent advances in plant molecular biology and biotechnologies have led to the identification of stress responsive genes and signaling pathways, which open up new paradigms to augment rice productivity. Accordingly, transcription factors, protein kinases and enzymes for generating protective metabolites and proteins all contribute to an intricate network of events that guard and maintain cellular integrity. In addition, various quantitative trait loci associated with elevated stress tolerance have been cloned, resulting in the detection of novel genes for biotic and abiotic stress resistance. Mechanistic understanding of the genetic basis of traits, such as N and P use, is allowing rice researchers to engineer nutrient-efficient rice varieties, which would result in higher yields with lower inputs. Likewise, the research in micronutrients biosynthesis opens doors to genetic engineering of metabolic pathways to enhance micronutrients production. With third generation sequencing techniques on the horizon, exciting progress can be expected to vastly improve molecular markers for gene-trait associations forecast with increasing accuracy. This book emphasizes on the areas of rice science that attempt to overcome the foremost limitations in rice production. Our intention is to highlight research advances in the fields of physiology, molecular breeding and genetics, with a special focus on increasing productivity, improving biotic and abiotic stress tolerance and nutritional quality of rice.
The production of doubled haploids has become a necessary tool in advanced plant breeding institutes and commercial companies for breeding many crop species. However, the development of new, more efficient and cheaper large scale production protocols has meant that doubled haploids are also recently being applied in less advanced breeding programmes. This Manual was prepared to stimulate the wider use of this technology for speeding and opening up new breeding possibilities for many crops including some woody tree species. Since the construction of genetic maps using molecular markers requires the development of segregating doubled haploid populations in numerous crop species, we hope that this Manual will also help molecular biologists in establishing such mapping populations. For many years, both the Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA) have supported and coordinated research that focuses on development of more efficient doubled haploid production methods and their applications in breeding of new varieties and basic research through their Plant Breeding and Genetics Section of the Joint F AO/IAEA Division of Nuclear Techniques in Food and Agriculture. The first F AO/IAEA scientific network (Coordinated Research Programme - CRP) dealing with doubled haploids was initiated by the Plant Breeding and Genetics Section in 1986.
During the past decade, there has been tremendous progress in maize biotechnology. This volume provides an overview of our current knowledge of maize molecular genetics, how it is being used to improve the crop, and future possibilities for crop enhancement. Several chapters deal with genetically engineered traits that are currently, or soon will be, in commercial production. Technical approaches for introducing novel genes into the maize genome, the regeneration of plants from transformed cells, and the creation of transgenic lines for field production are covered. Further, the authors describe how molecular genetic techniques are being used to identify genes and characterize their function, and how these procedures are utilized to develop elite maize germplasm. Moreover, molecular biology and physiological studies of corn as a basis for the improvement of its nutritional and food-making properties are included. Finally, the growing use of corn as biomass for energy production is discussed.
Global population is mounting at an alarming stride to surpass 9.3 billion by 2050, whereas simultaneously the agricultural productivity is gravely affected by climate changes resulting in increased biotic and abiotic stresses. The genus Brassica belongs to the mustard family whose members are known as cruciferous vegetables, cabbages or mustard plants. Rapeseed-mustard is world’s third most important source of edible oil after soybean and oil palm. It has worldwide acceptance owing to its rare combination of health promoting factors. It has very low levels of saturated fatty acids which make it the healthiest edible oil that is commonly available. Apart from this, it is rich in antioxidants by virtue of tocopherols and phytosterols presence in the oil. The high omega 3 content reduces the risk of atherosclerosis/heart attack. Conventional breeding methods have met with limited success in Brassica because yield and stress resilience are polygenic traits and are greatly influenced by environment. Therefore, it is imperative to accelerate the efforts to unravel the biochemical, physiological and molecular mechanisms underlying yield, quality and tolerance towards biotic and abiotic stresses in Brassica. To exploit its fullest potential, systematic efforts are needed to unlock the genetic information for new germplasms that tolerate initial and terminal state heat coupled with moisture stress. For instance, wild relatives may be exploited in developing introgressed and resynthesized lines with desirable attributes. Exploitation of heterosis is another important area which can be achieved by introducing transgenics to raise stable CMS lines. Doubled haploid breeding and marker assisted selection should be employed along with conventional breeding. Breeding programmes aim at enhancing resource use efficiency, especially nutrient and water as well as adoption to aberrant environmental changes should also be considered. Biotechnological interventions are essential for altering the biosynthetic pathways for developing high oleic and low linolenic lines. Accordingly, tools such as microspore and ovule culture, embryo rescue, isolation of trait specific genes especially for aphid, Sclerotinia and alternaria blight resistance, etc. along with identification of potential lines based on genetic diversity can assist ongoing breeding programmes. In this book, we highlight the recent molecular, genetic and genomic interventions made to achieve crop improvement in terms of yield increase, quality and stress tolerance in Brassica, with a special emphasis in Rapeseed-mustard.
Maize is one of the world’s highest value crops, with a multibillion dollar annual contribution to agriculture. The great adaptability and high yields available for maize as a food, feed and forage crop have led to its current production on over 140 million hectares worldwide, with acreage continuing to grow at the expense of other crops. In terms of tons of cereal grain produced worldwide, maize has been number one for many years. Moreover, maize is expanding its contribution to non-food uses, including as a major source of ethanol as a fuel additive or fuel alternative in the US. In addition, maize has been at the center of the transgenic plant controversy, serving as the first food crop with released transgenic varieties. By 2008, maize will have its genome sequence released, providing the sequence of the first average-size plant genome (the four plant genomes that are now sequenced come from unusually tiny genomes) and of the most complex genome sequenced from any organism. Among plant science researchers, maize has the second largest and most productive research community, trailing only the Arabidopsis community in scale and significance. At the applied research and commercial improvement levels, maize has no peers in agriculture, and consists of thousands of contributors worthwhile. A comprehensive book on the biology of maize has not been published. The "Handbook of Maize: the Genetics and Genomics" center on the past, present and future of maize as a model for plant science research and crop improvement. The books include brief, focused chapters from the foremost maize experts and feature a succinct collection of informative images representing the maize germplasm collection.
Doubled haploid technology is an important tool for plant breeding. It allows for significant time reduction in the achievement of homozygous breeding lines of value in crop improvement. This volume provides an excellent overview of haploid induction and the application of doubled haploids. The authors emphasize advances made in the understanding of microspore embryogenesis, but treat also advances in gynogenesis and the manipulation of parthenogenetic haploid development. The text contains a thorough discussion of the application of haploidy to the improvement of a number of species from various families, including Brassicaceae, Poaceae, and Solanaceae. The various methods applicable to these species are described in detail. Each chapter contains critical evaluation of the scientific literature and an extensive list of references. This volume is ideally suited for plant breeders, geneticists, and plant cell biologists.
This paper provides guidelines for new high-throughput screening methods – both phenotypic and genotypic – to enable the detection of rare mutant traits, and reviews techniques for increasing the efficiency of crop mutation breeding.
The Alliums are some of the most ancient cultivated crops and include onions, garlic, leeks and other related plants. This book provides an up-to-date review of Allium science for postgraduates and researchers. It contains commissioned chapters on topics that have shown major advances particularly in the last ten years such as molecular biology, floriculture and biofertilizers.
