Development and Application of Genomic Models for Large-Crop Plant Genomes

Plant genomes vary enormously in size. A part of this variation is generated by polyploidy, which is ubiquitous in the plant kingdom; however, even between closely related, ostensibly diploid species, it can still vary by an order of magnitude. A notable, but not atypical example is the contrast between rice (1 C DNA content of 0.50 pg, equivalent to 450 Mbp) and barley (5.55 pg, 5300 Mbp). The gene content of these two species is thought to be rather similar, numbering something under 40,000, depending on the gene prediction program employed [1]. Thus, much of the difference in DNA content is made up of nongenic DNA—in particular, retrotransposons

Model Plants and Crop Improvement

Within the past decade, there has been an explosion of research in both the public and private sectors regarding the use of plant genetic models to improve crop yield. Bringing together experts from across the globe, Model Plants and Crop Improvement provides a critical assessment of the potential of model plant species for crop improvement. The first comprehensive summary of the use of model plant systems, the book delineates the model species' contribution to understanding the genomes of crop species. The book provides an in-depth examination of the achievements and limitations of the model paradigm. It explores how continued research in models can contribute to the goal of delivering the outputs of molecular biology to crops. Covering the major genetic models such as Arabidopsis thaliana, Lotus japonicus, and Medigago, the book goes on to discuss applications to food plants of global importance including rice, canola, and legumes. The book introduces the evolutionary, genetic, genomic, and morphological attributes of B. distachyon that make it such an attractive new model plant system. As the post-genomic era dawns, a key question to address is how this growing body of genetic and biological information can be extended beyond the model to the modeled species. This book takes you one step closer to applying modeling results to crops in the field

Perennial Lymegrass (Leymus arenarius and L. mollis) as Potential Crop Species for Northern Latitudes

The aim of the present study is to improve the perennial lymegrass (L. arenarius and L. mollis) for cultivation as potential cereal crop for Iceland as well as for other regions of native lymegrass distribution. The study will also provide cereal breeders with broader genetic resource containing several characters of the wild species such as tolerance to extreme environments and perhaps resistance to pathological diseases

Developing a framework for arts in health programs targeting individuals with chronic pain: a mixed-methods study of practitioners

Objectives: Chronic pain is a leading cause of morbidity and disability across the world. Cultural engagement may be a valuable tool in addressing the social disconnection that often accompanies chronic pain. This study sought to develop a framework for arts in health programs targeting individuals with chronic pain. / Study design: Sequential explanatory mixed-methods study. / Methods: Web-based, cross-sectional survey sent to arts and cultural professionals to assess their experience with arts in health programming. Semi-structured interviews conducted with a sample of survey respondents to explore their perspectives on targeted arts in health programming for individuals with chronic pain. / Results: Between October 2019 and January 2020, 208 surveys were completed by arts and cultural professionals. One hundred and twenty (58%) of the respondents indicated that they currently run an arts in health or museums in health program. Among these 120 respondents, 52 (43%) targeted older adults, 50 (42%) targeted individuals with mental health concerns, and 18 (15%) targeted individuals living with pain. Improving well-being (101 [84%]) and reducing social isolation (90 [75%]) were the most common intended program outcomes, while improving pain was the least common outcome (26 [22%]). Fifteen survey respondents were interviewed. Interviewees identified four interdependent themes regarding best practices for arts in health programs pertaining to (1) program content and structure, (2) program facilitation, (3) partnerships, and (4) programs for individuals with chronic pain. / Conclusions: The cultural sector can support chronic pain prevention and treatment efforts through the development of specialized programs. This study provides a framework for developing arts in health programs that support individuals living with chronic pain

Resistance to the cereal cyst nematode (Heterodera avenae) transferred from the wild grass Aegilops ventricosa to hexaploid wheat by a "stepping-stone" procedure

Transfer of resistance toHeterodera avenae, the cereal cyst nematode (CCN), by a stepping-stoneprocedure from the wild grassAegilops ventricosa to hexaploid wheat has been demonstrated. The number of nematodes per plant was lower, and reached a plateau much earlier, in the resistant introgression line H93-8 (1–2 nematodes per plant) than in the recipient H10-15 wheat (14–16 nematodes per plant). Necrosis (hypersensitive reaction) near the nematode, little cell fusion, and few, often degraded syncytia were observed in infested H93-8 roots, while abundant, well-formed syncytia were present in the susceptible H10-15 wheat. Line H93-8 was highly resistant to the two Spanish populations tested, as well as the four French races (Fr1-Fr4), and the British pathotype Hall, but was susceptible to the Swedish pathotypes HgI and HgIII. Resistance was inherited as though determined by a single quasi-dominant factor in the F2 generations resulting from crosses of H93-8 with H10-15 and with Loros, a resistant wheat carrying the geneCre1 (syn.Ccn1). The resistance gene in H93-8 (Cre2 orCcn2) is not allelic with respect to that in Loros. RFLPs and other markers, together with the cytogenetical evidence, indicate that theCre2 gene has been integrated into a wheat chromosome without affecting its meiotic pairing ability. Introduction ofCre2 by backcrossing into a commercial wheat backgroud increases grain yield when under challenge by the nematode and is not detrimental in the absence of infestation

Homoeologous gene silencing in tissue cultured wheat callus

Abstract Background In contrast to diploids, most polyploid plant species, which include the hexaploid bread wheat, possess an additional layer of epigenetic complexity. Several studies have demonstrated that polyploids are affected by homoeologous gene silencing, a process in which sub-genomic genomic copies are selectively transcriptionally inactivated. This form of silencing can be tissue specific and may be linked to developmental or stress responses. Results Evidence was sought as to whether the frequency of homoeologous silencing in in vitro cultured wheat callus differ from that in differentiated organs, given that disorganized cells are associated with a globally lower level of DNA methylation. Using a reverse transcription PCR (RT-PCR) single strand conformation polymorphism (SSCP) platform to detect the pattern of expression of 20 homoeologous sets of single-copy genes known to be affected by this form of silencing in the root and/or leaf, we observed no silencing in any of the wheat callus tissue tested. Conclusion Our results suggest that much of the homoeologous silencing observed in differentiated tissues is probably under epigenetic control, rather than being linked to genomic instability arising from allopolyploidization. This study reinforces the notion of plasticity in the wheat epi-genome.</p

The GCP molecular marker toolkit, an instrument for use in breeding food security crops

Crop genetic resources carry variation useful for overcoming the challenges of modern agriculture. Molecular markers can facilitate the selection of agronomically important traits. The pervasiveness of genomics research has led to an overwhelming number of publications and databases, which are, nevertheless, scattered and hence often difficult for plant breeders to access, particularly those in developing countries. This situation separates them from developed countries, which have better endowed programs for developing varieties. To close this growing knowledge gap, we conducted an intensive literature review and consulted with more than 150 crop experts on the use of molecular markers in the breeding program of 19 food security crops. The result was a list of effectively used and highly reproducible sequence tagged site (STS), simple sequence repeat (SSR), single nucleotide polymorphism (SNP), and sequence characterized amplified region (SCAR) markers. However, only 12 food crops had molecular markers suitable for improvement. That is, marker-assisted selection is not yet used for Musa spp., coconut, lentils, millets, pigeonpea, sweet potato, and yam. For the other 12 crops, 214 molecular markers were found to be effectively used in association with 74 different traits. Results were compiled as the GCP Molecular Marker Toolkit, a free online tool that aims to promote the adoption of molecular approaches in breeding activities

Inherited epidermolysis bullosa

Inherited epidermolysis bullosa (EB) encompasses a number of disorders characterized by recurrent blister formation as the result of structural fragility within the skin and selected other tissues. All types and subtypes of EB are rare; the overall incidence and prevalence of the disease within the United States is approximately 19 per one million live births and 8 per one million population, respectively. Clinical manifestations range widely, from localized blistering of the hands and feet to generalized blistering of the skin and oral cavity, and injury to many internal organs. Each EB subtype is known to arise from mutations within the genes encoding for several different proteins, each of which is intimately involved in the maintenance of keratinocyte structural stability or adhesion of the keratinocyte to the underlying dermis. EB is best diagnosed and subclassified by the collective findings obtained via detailed personal and family history, in concert with the results of immunofluorescence antigenic mapping, transmission electron microscopy, and in some cases, by DNA analysis. Optimal patient management requires a multidisciplinary approach, and revolves around the protection of susceptible tissues against trauma, use of sophisticated wound care dressings, aggressive nutritional support, and early medical or surgical interventions to correct whenever possible the extracutaneous complications. Prognosis varies considerably and is based on both EB subtype and the overall health of the patient

Inheritance and relationships of flowering time and seed size in kabuli chickpea

Flowering time and seed size are the important traits for adaptation in chickpea. Early phenology (time of flowering, podding and maturity) enhance chickpea adaptation to short season environments. Along with a trait of consumer preference, seed size has also been considered as an important factor for subsequent plant growth parameters including germination, seedling vigour and seedling mass. Small seeded kabuli genotype ICC 16644 was crossed with four genotypes (JGK 2, KAK 2, KRIPA and ICC 17109) to study inheritance of flowering time and seed size. The relationships of phenology with seed size, grain yield and its component traits were studied. The study included parents, F1, F2 and F3 of four crosses. The segregation data of F2 indicated flowering time in chickpea was governed by two genes with duplicate recessive epistasis and lateness was dominant to earliness. Two genes were controlling 100-seed weight where small seed size was dominant over large seed size. Early phenology had significant negative or no association (ICC 16644 × ICC 17109) with 100-seed weight. Yield per plant had significant positive association with number of seeds per plant, number of pods per plant, biological yield per plant, 100-seed weight, harvest index and plant height and hence could be considered as factors for seed yield improvement. Phenology had no correlation with yield per se (seed yield per plant) in any of the crosses studied. Thus, present study shows that in certain genetic background it might be possible to breed early flowering genotypes with large seed size in chickpea and selection of early flowering genotypes may not essentially have a yield penalty