159 research outputs found
Ethical Considerations in Agro-biodiversity Research, Collecting, and Use
Humans have always played a crucial role in the evolutionary dynamics of agricultural biodiversity and thus there is a strong relationship between these resources and human cultures. These agricultural resources have long been treated as a global public good, and constitute the livelihoods of millions of predominantly poor people. At the same time, agricultural biodiversity is under serious threat in many parts of the world despite extensive conservation efforts. Ethical considerations regarding the collecting, research, and use of agricultural biodiversity are currently topics of great concern. For example, easy access to genetic resources for breeding purposes is important, but international agreements and legal frameworks are necessary to ensure adequate recognition of the contributions of local communities and traditional farmers in creating and nurturing these resources. Here, we assess ethical principles in the context of existing codes of conduct that are relevant for agro-biodiversity researchers. We aim to create awareness among scientists and policy makers who are concerned with agro-biodiversity research and its potential impact on local communities. We encourage a serious assessment of the ethical principles presented here and hope to facilitate an integration of these principles into the reader's personal ethical framework. Key ethical principles considered here include the importance of obtaining prior informed consent, equity, and the inalienability of rights of local communities and farmers
Patterns of domestication in the Ethiopian oil-seed crop noug (Guizotia abyssinica)
Noug (Guizotia abyssinica) is a semidomesticated oil-seed crop, which is primarily cultivated in Ethiopia. Unlike its closest crop relative, sunflower, noug has small seeds, small flowering heads, many branches, many flowering heads, and indeterminate flowering, and it shatters in the field. Here, we conducted common garden studies and microsatellite analyses of genetic variation to test whether high levels of crop–wild gene flow and/or unfavorable phenotypic correlations have hindered noug domestication. With the exception of one population, analyses of microsatellite variation failed to detect substantial recent admixture between noug and its wild progenitor. Likewise, only very weak correlations were found between seed mass and the number or size of flowering heads. Thus, noug's ‘atypical’ domestication syndrome does not seem to be a consequence of recent introgression or unfavorable phenotypic correlations. Nonetheless, our data do reveal evidence of local adaptation of noug cultivars to different precipitation regimes, as well as high levels of phenotypic plasticity, which may permit reasonable yields under diverse environmental conditions. Why noug has not been fully domesticated remains a mystery, but perhaps early farmers selected for resilience to episodic drought or untended environments rather than larger seeds. Domestication may also have been slowed by noug's outcrossing mating syste
Application of genomicsassisted breeding for generation of climate resilient crops: progress and prospects
CCAFS Climat
Crop wild relatives of the brinjal eggplant ( Solanum melongena ): Poorly represented in genebanks and many species at risk of extinction
This is the publisher's Early View pdf without final pagination .© 2016 Botanical Society of America. This is an open access article, available to all readers online, published under a creative commons license. The attached file is the published version of the article
Global agricultural intensification during climate change: A role for genomics
Summary: Agriculture is now facing the 'perfect storm' of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic-assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change. >
Diversity analysis of 80,000 wheat accessions reveals consequences and opportunities of selection footprints
Undomesticated wild species, crop wild relatives, and landraces represent sources of variation for wheat improvement to address challenges from climate change and the growing human population. Here, we study 56,342 domesticated hexaploid, 18,946 domesticated tetraploid and 3,903 crop wild relatives in a massive-scale genotyping and diversity analysis. Using DArTseqTM technology, we identify more than 300,000 high-quality SNPs and SilicoDArT markers and align them to three reference maps: the IWGSC RefSeq v1.0 genome assembly, the durum wheat genome assembly (cv. Svevo), and the DArT genetic map. On average, 72% of the markers are uniquely placed on these maps and 50% are linked to genes. The analysis reveals landraces with unexplored diversity and genetic footprints defined by regions under selection. This provides fertile ground to develop wheat varieties of the future by exploring specific gene or chromosome regions and identifying germplasm conserving allelic diversity missing in current breeding programs
Wheat genetic resources have avoided disease pandemics, improved food security, and reduced environmental footprints: A review of historical impacts and future opportunities
The use of plant genetic resources (PGR)—wild relatives, landraces, and isolated breeding gene pools—has had substantial impacts on wheat breeding for resistance to biotic and abiotic stresses, while increasing nutritional value, end-use quality, and grain yield. In the Global South, post-Green Revolution genetic yield gains are generally achieved with minimal additional inputs. As a result, production has increased, and millions of hectares of natural ecosystems have been spared. Without PGR-derived disease resistance, fungicide use would have easily doubled, massively increasing selection pressure for fungicide resistance. It is estimated that in wheat, a billion liters of fungicide application have been avoided just since 2000. This review presents examples of successful use of PGR including the relentless battle against wheat rust epidemics/pandemics, defending against diseases that jump species barriers like blast, biofortification giving nutrient-dense varieties and the use of novel genetic variation for improving polygenic traits like climate resilience. Crop breeding genepools urgently need to be diversified to increase yields across a range of environments (>200 Mha globally), under less predictable weather and biotic stress pressure, while increasing input use efficiency. Given that the ~0.8 m PGR in wheat collections worldwide are relatively untapped and massive impacts of the tiny fraction studied, larger scale screenings and introgression promise solutions to emerging challenges, facilitated by advanced phenomic and genomic tools. The first translocations in wheat to modify rhizosphere microbiome interaction (reducing biological nitrification, reducing greenhouse gases, and increasing nitrogen use efficiency) is a landmark proof of concept. Phenomics and next-generation sequencing have already elucidated exotic haplotypes associated with biotic and complex abiotic traits now mainstreamed in breeding. Big data from decades of global yield trials can elucidate the benefits of PGR across environments. This kind of impact cannot be achieved without widescale sharing of germplasm and other breeding technologies through networks and public–private partnerships in a pre-competitive space
A Disease-Mediated Trophic Cascade in the Serengeti and its Implications for Ecosystem C
The removal of rinderpest had cascading effects on herbivore populations, fire, tree density, and even ecosystem carbon in the Serengeti ecosystem of East Africa
Complete Chloroplast Genome Sequence of a Major Invasive Species, Crofton Weed (Ageratina adenophora)
Crofton weed (Ageratina adenophora) is one of the most hazardous invasive plant species, which causes serious economic losses and environmental damages worldwide. However, the sequence resource and genome information of A. adenophora are rather limited, making phylogenetic identification and evolutionary studies very difficult. Here, we report the complete sequence of the A. adenophora chloroplast (cp) genome based on Illumina sequencing.The A. adenophora cp genome is 150, 689 bp in length including a small single-copy (SSC) region of 18, 358 bp and a large single-copy (LSC) region of 84, 815 bp separated by a pair of inverted repeats (IRs) of 23, 755 bp. The genome contains 130 unique genes and 18 duplicated in the IR regions, with the gene content and organization similar to other Asteraceae cp genomes. Comparative analysis identified five DNA regions (ndhD-ccsA, psbI-trnS, ndhF-ycf1, ndhI-ndhG and atpA-trnR) containing parsimony-informative characters higher than 2%, which may be potential informative markers for barcoding and phylogenetic analysis. Repeat structure, codon usage and contraction of the IR were also investigated to reveal the pattern of evolution. Phylogenetic analysis demonstrated a sister relationship between A. adenophora and Guizotia abyssinica and supported a monophyly of the Asterales.We have assembled and analyzed the chloroplast genome of A. adenophora in this study, which was the first sequenced plastome in the Eupatorieae tribe. The complete chloroplast genome information is useful for plant phylogenetic and evolutionary studies within this invasive species and also within the Asteraceae family
Response of Sunflower (Helianthus annuus L.) Leaf Surface Defenses to Exogenous Methyl Jasmonate
Helianthus annuus, the common sunflower, produces a complex array of secondary compounds that are secreted into glandular trichomes, specialized structures found on leaf surfaces and anther appendages of flowers. The primary components of these trichome secretions are sesquiterpene lactones (STL), a diverse class of compounds produced abundantly by the plant family Compositae and believed to contribute to plant defense against herbivory. We treated wild and cultivated H. annuus accessions with exogenous methyl jasmonate, a plant hormone that mediates plant defense against insect herbivores and certain classes of fungal pathogens. The wild sunflower produced a higher density of glandular trichomes on its leaves than the cultivar. Comparison of the profiles of glandular trichome extracts obtained by liquid chromatography–mass spectroscopy (LC-MS) showed that wild and cultivated H. annuus were qualitatively similar in surface chemistry, although differing in the relative size and proportion of various compounds detected. Despite observing consistent transcriptional responses to methyl jasmonate treatment, we detected no significant effect on glandular trichome density or LC-MS profile in cultivated or wild sunflower, with wild sunflower exhibiting a declining trend in overall STL production and foliar glandular trichome density of jasmonate-treated plants. These results suggest that glandular trichomes and associated compounds may act as constitutive defenses or require greater levels of stimulus for induction than the observed transcriptional responses to exogenous jasmonate. Reduced defense investment in domesticated lines is consistent with predicted tradeoffs caused by selection for increased yield; future research will focus on the development of genetic resources to explicitly test the ecological roles of glandular trichomes and associated effects on plant growth and fitness
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