Development And Characterization Of Microsatellite Markers For The Grain Amaranths Amaranthus Spp L

The grain amaranths (Amaranthus hypochondriacus L., A. cruentus L., and A. caudatus L.) are important pseudocereals native to the Americas that have received increased attention for their nutritional content, specifically their balance of amino acids. The objective of this project was to produce and characterize a set of highly informative, reproducible microsatellite markers for the grain amaranths. A total of 1457 clones were sequenced from three genomic libraries enriched for the microsatellite motifs AAC, AAT and AC. Of these, 353 (24%) contained unique microsatellites. An additional 29 microsatellite loci were identified among 728 BAC-end sequences of a newly developed amaranth BAC library. Flanking primers were designed for 319 of the microsatellite loci and all were screened on a panel of diverse amaranths, including grain and weedy Amaranthus species. A total of 179 (56%) microsatellites were polymorphic across accessions from the three grain amaranths. Among these polymorphic microsatellite loci, a total of 731 alleles were identified with average of four alleles per locus. Heterozygosity values ranged from 0.14 to 0.83 with a mean value of 0.62. Thirty-seven (21%) of the markers were polymorphic between the parents of a segregating population and were shown to be inherited in a normal Mendelian fashion based on chi-squared analysis, demonstrating the utility of these markers for linkage mapping of the amaranth genome. Phylogenetic analysis using the marker data showed A. hybridus accessions in two of the three major grain amaranth clades, suggesting the polyphyletic evolution of the three cultivated species from different A. hybridus ancestors. The microsatellite markers reported here will be useful for further evaluating the relationships among the grain amaranths and their relatives and are an ideal resource for use in marker-assisted breeding programs, germplasm analysis and varietal identification. The transferability of these markers to A. hybridus, A. powellii, and A. retroflexus as reported here suggests that the markers may be useful to other species with the genus Amaranthus, including economically important weeds, vegetable amaranths, and ornamentals.

This book describes the development of genetic resources in amaranths, with a major focus on genomics, reverse, and forward genetics tools and strategies that have been developed for crop improvement. Amaranth is an ancient crop native to the New World. Interest in amaranths is being renewed, due to their adaptability, stress tolerance, and nutritional value. There are about 65 species in the genus, including Amaranthus caudatus L., A. cruentus L., and A. hypochondriacus L., which are primarily grown as protein-rich grains or pseudocereals. The genus also includes major noxious weeds (e.g., A. palmeri). The amaranths are within the Caryophyllales order and thus many species (e.g., A. tricolor) produce red (betacyanin) or yellow (betaxanthin) betalain pigments, which are chemically distinct from the anthocyanins responsible for red pigmentation in other plants. A. hypochondriacus, which shows disomic inheritance (2n = 32; n= 466 Mb), has been sequenced and annotated with 23,059 protein-coding genes. Additional members of the genus are now also been sequenced including weedy amaranths, other grain amaranths, and their putative progenitors.

This book caters to the need of researchers working in the ever-evolving field of agricultural biotechnology. It discusses and provides in-depth information about latest advancements happening in this field. The book discusses evolution of plant tissue culture techniques, development of doubled haploids technology, role of recombinant-DNA technology in crop improvement. It also provides an insight into the global status of genetically modified crops, use of RNAi technology and mi-RNAs in plant improvement. Chapters are also dedicated for different branches of ‘omics’ science including genomics, bioinformatics, proteomics, metabolomics and phenomics along with the use of molecular markers in tagging and mapping of various genes/QTLs of agronomic importance. This book also covers the role of enzymes and microbes in agriculture in productivity enhancement. It is of interest to teachers, researchers of biotechnology and agriculture scientists. Also the book serves as additional reading material for undergraduate and postgraduate students of biotechnology, agriculture, horticulture, forestry, ecology, soil science, and environmental sciences. National and international biotechnologists and agricultural scientists will also find this to be a useful read.

This book presents deliberations on molecular and genomic mechanisms underlying the interactions of crop plants to the abiotic stresses caused by heat, cold, drought, flooding, submergence, salinity, acidity, etc., 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 vegetable 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 abiotic stresses. The nine chapters each dedicated to a vegetable crop or crop group in this volume elucidate on different types of abiotic stresses and their effects on and interaction with the crop; enumerate on the available genetic diversity with regard to abiotic 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 abiotic 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 abiotic stress-resistant crops

Neglected and Underutilized Crops: Future Smart Food explores future food crops with climate resilience potential. Sections cover their botany, nutritional significance, global distribution, production technology, and tolerance to biotic and abiotic stresses of neglected and underutilized crops. By simply changing species in a crop rotation system, the cycle of some pests and diseases is disrupted and probabilities of infestations are reduced. Finally, the book provides case studies that highlight where the adaptation of crops to local environments, especially with regard to climate change, have been successful.These crops can help make agricultural production systems more resilient to climate change. Although a few books on neglected and underutilized crops are available, this comprehensive book covers the full scope of crop husbandry, nutritional significance and global distribution. Contains consistent coverage of botany, nutritional significance, production technology, and tolerance to biotic and abiotic stresses Presents case studies of success stories where adaptations in local environments have made a difference, especially with climate change Addresses key opportunities for improving global food security

"Education, arts and social sciences, natural and technical sciences in the United States and Canada".

This book reviews the history, current state of knowledge, and different research approaches and techniques of studies on interactions between humans and plants in an important area of agriculture and ongoing plant domestication: Mesoamerica. Leading scholars and key research groups in Mexico discuss essential topics as well as contributions from international research groups that have conducted studies on ethnobotany and domestication of plants in the region. Such a convocation will produce an interesting discussion about future investigation and conservation of regional human cultures, genetic resources, and cultural and ecological processes that are critical for global sustainability.

Biotic stresses cause yield loss of 31-42% in crops in addition to 6-20% during post-harvest stage. Understanding interaction of crop plants to the biotic stresses caused by insects, bacteria, fungi, viruses, and oomycetes, etc. is important to develop resistant crop varieties. Knowledge on the advanced genetic and genomic crop improvement strategies including molecular breeding, transgenics, genomics-assisted breeding and the recently emerging genome editing for developing resistant varieties in vegetable crops is imperative for addressing FPNEE (food, health, nutrition. energy and environment) security. Whole genome sequencing of these crops followed by genotyping-by-sequencing have facilitated precise information about 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 nine chapters each dedicated to a vegetable crop or crop-group in this volume will deliberate on different types of biotic stress agents and their effects on and interaction with crop plants; will 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; will brief on the classical genetics of stress resistance and traditional breeding for transferring them to their cultivated counterparts; will enunciate the success stories of genetic engineering for developing biotic stress resistant varieties; will discuss on molecular mapping of genes and QTLs underlying biotic stress resistance and their marker-assisted introgression into elite varieties; will enunciate on different emerging genomics-aided techniques including genomic selection, allele mining, gene discovery and gene pyramiding for developing resistant crop varieties with higher quantity and better quality; and will also elaborate some case studies on genome editing focusing on specific genes for generating disease and insect resistant crops.

This book serves the larger community of plant researchers working on the taxonomy, species delimitation, phylogeny, and biogeography of pseudo-cereals, with a special emphasis on amaranths. It also provides extensive information on the nutritive value of underutilized pseudo-cereals, the goal being to broaden the vegetable list. Amaranthus is a cosmopolitan genus of annual or short-lived perennial plants. Most of the species are summer annual weeds and are commonly referred to as pigweed. Only a few are cultivated as vitamin-rich vegetables and ornamentals. The protein-rich seeds of a handful of species, known as grain amaranths, are consumed as pseudo-cereals. Amaranthusmanifests considerable morphological diversity among and even within certain species, and there is no general agreement on the taxonomy or number of species. Currently the genus Amaranthus is believed to include three recognized subgenera and 70 species. Amatanthus is considered to potentially offer an alternative crop in temperate and tropical climate. The classification of amaranths is ambiguous due to the lack of discrete and quantitative species-defining characteristics and the wide range of phenotypic plasticity, as well as introgression and hybridization involving weedy and crop species. It is a known fact that both vegetable and grain amaranths have evolved from their respective weed progenitors. There are more than 180 different weed species that are herbicide-resistant, and amaranths are considered to be leading members of the resistant biotypes. Amaranth species provide ample scope for investigating herbicide resistance mechanisms. Amaranths also show variability in terms of their mating behavior and germplasm, adaptability to different growing conditions, and wide range of variability in sexual systems, from monoecy to dioecy. A solid grasp of these parameters is essential to the future utilization of amaranths as super crops. There are quite a few amaranth research center and germplasm collections all over the world that maintain and evaluate working germplasms. To date, the genetic improvement of amaranths has primarily involved the application of conventional selection methods. But advances in genomics and biotechnology have dramatically enriched the potential to manipulate the amaranth genome, especially improving the amount and availability of nutrients. In conclusion, the book covers all aspects of amaranths, including their food value, significance as vegetables and pseudo-cereals, taxonomy, phylogeny, germplasm variability, breeding behavior and strategies, cultivation practices, and variability in terms of their sexual systems. It offers a valuable resource for all students, researchers and experts working in the field of plant taxonomy and diversity.