Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.770
Filtrar
1.
GM Crops Food ; 12(1): 192-211, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33380258

RESUMO

Evolution of resistance to genetically modified Bacillus thuringiensis (Bt) crops in pest populations is a major threat to the sustainability of the technology. Incidents of field resistance that have led to control problems of Bt crops or significantly reduced susceptibility of individual Bt proteins in pyramided plants have increased dramatically across the world, especially in recent years. Analysis of globally published data showed that 61.5% and 60.0% of the cases of resistance with major alleles that allowed homozygous resistant genotypes to survival on Bt crops were functionally non-recessive and did not involve fitness costs, respectively. Dominance levels (DFLs) measured on Bt plants ranged from -0.02 to 1.56 with a mean (± sem) of 0.35 ± 0.13 for the 13 cases of single-gene resistance to Bt plants that have been evaluated. Among these, all six cases with field control problems were functionally non-recessive with a mean DFL of 0.63 ± 0.24, which was significantly greater than the DFL (0.11 ± 0.07) of the seven cases without field resistance. In addition, index of fitness costs (IFC) of major resistance was calculated for each case based on the fitness of resistant (R'R') and heterozygous (R'S') genotypes on non-Bt plants divided by the fitness of their susceptible (S'S') counterparts. The estimated IFCs for 15 cases of single-gene resistance were similar for R'R' and R'S', and for the cases with and without field resistance; and the values averaged 1.10 ± 0.12 for R'R' and 1.20 ± 0.18 for R'S'. Limited published data suggest that resistance of insects to dual/multiple-gene Bt crops is likely to be more recessive than the related single-gene resistance, but their IFCs are similar. The quantitative analysis of the global data documents that the prevalence of non-recessive resistance has played an essential role in the widespread evolution of resistance to Bt crops, while the lack of fitness costs is apparently not as critical as the non-recessive resistance. The results suggest that planting of 'high dose' traits is an effective method for Bt crop IRM and more comprehensive management strategies that are also effective for functionally non-recessive resistance should be deployed.


Assuntos
Bacillus thuringiensis , Animais , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Produtos Agrícolas/genética , Endotoxinas , Proteínas Hemolisinas/genética , Insetos , Resistência a Inseticidas/genética , Controle Biológico de Vetores , Plantas Geneticamente Modificadas
2.
Sci Total Environ ; 750: 141422, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32858290

RESUMO

Glyphosate-based herbicides (GBHs) are the most frequently used herbicides globally. They were launched as a safe solution for weed control, but recently, an increasing number of studies have shown the existence of GBH residues and highlighted the associated risks they pose throughout ecosystems. Conventional agricultural practices often include the use of GBHs, and the use of glyphosate-resistant genetically modified crops is largely based on the application of glyphosate, which increases the likelihood of its residues ending up in animal feed. These residues persist throughout the digestive process of production animals and accumulate in their excretion products. The poultry industry, in particular, is rapidly growing, and excreted products are used as plant fertilizers in line with circular food economy practices. We studied the potential effects of unintentional glyphosate contamination on an agronomically important forage grass, meadow fescue (Festuca pratensis) and a horticulturally important strawberry (Fragaria x vescana) using glyphosate residues containing poultry manure as a plant fertilizer in a common garden experiment. Glyphosate in the manure decreased plant growth in both species and vegetative reproduction in F. x vescana. Furthermore, our results indicate that glyphosate residues in organic fertilizers might have indirect effects on sexual reproduction in F. pratensis and herbivory in F. x vescana because they positively correlate with plant size. Our results highlight that glyphosate can be unintentionally spread via organic fertilizer, counteracting its ability to promote plant growth.


Assuntos
Fertilizantes , Herbicidas , Animais , Produtos Agrícolas/genética , Ecossistema , Glicina/análogos & derivados , Herbicidas/toxicidade , Esterco , Plantas Geneticamente Modificadas
3.
GM Crops Food ; 12(1): 71-83, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-32997586

RESUMO

This study assessed the farm-level economic and environmental impacts from the use of genetically modified (GM) corn in Vietnam (resistant to Lepidopteran pests of corn and tolerant to the herbicide glyphosate). It was largely based on a farmer survey conducted in 2018-19. The GM varieties out-performed conventional varieties in terms of yield by +30.4% (+15.2% if the yield comparison is with only the nearest performing equivalent conventional varieties) and reduced the cost of production by between US $26.47 per ha and US $31.30 per ha. For every extra US $1 spent on GM seed relative to conventional seed, farmers gained between an additional US $6.84 and US $12.55 in extra income. The GM maize technology also reduced insecticide and herbicide use. The average amount of herbicide active ingredient applied to the GM crop area was 26% lower (1.66 kg per ha) than the average value for the conventional corn area (2.26 kg/ai per ha) and in terms of the associated environmental impact of the herbicide use, as measured by the Environmental Impact Quotient (EIQ) indicator, it was lower by 36% than the average value applicable to the conventional corn area. Insecticides were used on a significantly lower GM crop area and, when used, in smaller amounts. The average amount of insecticide applied to the GM corn crop was significantly lower by 78% (0.08 kg/ai per ha) than the average value for the conventional corn area (0.36 kg/ai per ha) and in terms of the associated environmental impact of the insecticide use, as measured by the EIQ indicator, it was also lower by 77% than the average value for conventional corn (14.06 per ha).


Assuntos
Produtos Agrícolas/genética , Zea mays/genética , Fazendas , Plantas Geneticamente Modificadas/genética , Inquéritos e Questionários , Vietnã
4.
Food Chem ; 334: 127608, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711280

RESUMO

Food analysis to ensure food safety and quality are relevant to all countries. This study aimed to develop a detection technique by combining recombinase polymerase amplification with CRISPR-Cas12a for food safety (termed RPA-Cas12a-FS). Our data showed that this novel method could be detected via fluorescence intensity for the molecular identification of foodborne pathogenic bacteria, genetically modified crops, and meat adulteration. After optimization, the sensitivity and stability of RPA-Cas12a-FS was further enhanced. The RPA-Cas12a-FS system could specifically detect target gene levels as low as 10 copies in 45 min at 37 °C. The RPA-Cas12a-FS system was sensitive both using standard samples in the lab and using samples from the field, which indicated that this detection method was practical. In conclusion, a simple, rapid, and highly sensitive detection method based on CRISPR-Cas12a was developed for molecular identification in the food safety field without requiring technical expertise or ancillary equipment.


Assuntos
Sistemas CRISPR-Cas , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Proteínas de Bactérias/genética , Proteínas Associadas a CRISPR/genética , Produtos Agrícolas/genética , Endodesoxirribonucleases/genética , Fluorescência , Inocuidade dos Alimentos , Carne , Plantas Geneticamente Modificadas/genética , RNA Guia , Recombinases/genética , Sensibilidade e Especificidade
5.
GM Crops Food ; 12(1): 106-114, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33079624

RESUMO

Agricultural biotechnology is enhancing agricultural productivity, food security, and livelihoods globally. Some developing countries have established functional biosafety regulatory systems and have commercialized genetically modified (GM) crops. Release of GM crops requires enhanced capacity for regulatory compliance and product stewardship to help ensure sustainable use of biotechnology products. We conducted a survey of 66 stakeholders, mostly from Africa and Asia, in two-week international agricultural biotechnology short courses. Respondents showed knowledge of biotechnology benefits and expressed potential barriers to commercialization. They identified 16 crops in the "pipeline for commercialization." Stakeholders also shared ideas about how to build capacity for product stewardship. Product stewardship is a concept which requires each person in the product life cycle - innovators, scientists, and technology users, to share responsibility. This paper focuses on adoption of product stewardship for post-release management of GM crops which encompasses trait performance, resistance management, integrated pest management (IPM), good agricultural practices, high-quality seeds and planting material, intellectual property management, labeling, identity preservation, consumer acceptance, and effective marketing.


Assuntos
Biotecnologia , Produtos Agrícolas , Agricultura , Produtos Agrícolas/genética , Abastecimento de Alimentos , Plantas Geneticamente Modificadas
6.
GM Crops Food ; 12(1): 125-144, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33079628

RESUMO

Plants are susceptible to phytopathogens, including bacteria, fungi, and viruses, which cause colossal financial shortfalls (pre- and post-harvest) and threaten global food safety. To combat with these phytopathogens, plant possesses two-layer of defense in the form of PAMP-triggered immunity (PTI), or Effectors-triggered immunity (ETI). The understanding of plant-molecular interactions and revolution of high-throughput molecular techniques have opened the door for innovations in developing pathogen-resistant plants. In this context, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) has transformed genome editing (GE) technology and being harnessed for altering the traits. Here we have summarized the complexities of plant immune system and the use of CRISPR-Cas9 to edit the various components of plant immune system to acquire long-lasting resistance in plants against phytopathogens. This review also sheds the light on the limitations of CRISPR-Cas9 system, regulation of CRISPR-Cas9 edited crops and future prospective of this technology.


Assuntos
Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Sistemas CRISPR-Cas/genética , Produtos Agrícolas/genética , Edição de Genes , Doenças das Plantas/genética
7.
GM Crops Food ; 12(1): 18-24, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32787504

RESUMO

Since 1996 till 2018, the global area cultivated with GM crops has increased 113-fold, making biotech crops one of the fastest adopted crop technology in the past decades. In the European Union, only two countries still cultivate one available transgenic crop event on minor hectarage. Moreover, the number of notifications for confined field trials has dramatically dropped in the last decade. All these are happening while the EU legislation on GM crops has come under severe criticism. The percentage of EU citizens concerned about the presence of GMOs in the environment has decreased from 30% (in 2002) to 19% (in 2011), while the level of concern about the use of GM ingredients in food or drinks has decreased from 63% (in 2005) to 27% (in 2019). The steadily increasing acceptance of the EU citizens of GMOs in the environment and food, as it was recorded by Eurobarometers, should additionally ease the way and support a positive change of the legal framework that regulates the GM crops' testing and commercial cultivation in the EU.


Assuntos
Biotecnologia , Produtos Agrícolas/genética , Animais , Animais Geneticamente Modificados , União Europeia , Plantas Geneticamente Modificadas
8.
GM Crops Food ; 12(1): 57-70, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877304

RESUMO

Hybrid seeds of several important crops with supreme qualities including yield, biotic and abiotic stress tolerance have been cultivated for decades. Thus far, a major challenge with hybrid seeds is that they do not have the ability to produce plants with the same qualities over subsequent generations. Apomixis, an asexual mode of reproduction by avoiding meiosis, exists naturally in flowering plants, and ultimately leads to seed production. Apomixis has the potential to preserve hybrid vigor for multiple generations in economically important plant genotypes. The evolution and genetics of asexual seed production are unclear, and much more effort will be required to determine the genetic architecture of this phenomenon. To fix hybrid vigor, synthetic apomixis has been suggested. The development of MiMe (mitosis instead of meiosis) genotypes has been utilized for clonal gamete production. However, the identification and parental origin of genes responsible for synthetic apomixis are little known and need further clarification. Genome modifications utilizing genome editing technologies (GETs), such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (cas), a reverse genetics tool, have paved the way toward the utilization of emerging technologies in plant molecular biology. Over the last decade, several genes in important crops have been successfully edited. The vast availability of GETs has made functional genomics studies easy to conduct in crops important for food security. Disruption in the expression of genes specific to egg cell MATRILINEAL (MTL) through the CRISPR/Cas genome editing system promotes the induction of haploid seed, whereas triple knockout of the Baby Boom (BBM) genes BBM1, BBM2, and BBM3 cause embryo arrest and abortion, which can be fully rescued by male-transmitted BBM1. The establishment of synthetic apomixis by engineering the MiMe genotype by genome editing of BBM1 expression or disruption of MTL leads to clonal seed production and heritability for multiple generations. In the present review, we discuss current developments related to the use of CRISPR/Cas technology in plants and the possibility of promoting apomixis in crops to preserve hybrid vigor. In addition, genetics, evolution, epigenetic modifications, and strategies for MiMe genotype development are discussed in detail.


Assuntos
Apomixia , Sistemas CRISPR-Cas , Produtos Agrícolas/genética , Edição de Genes , Vigor Híbrido , Sementes
9.
Food Chem ; 335: 127627, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32738534

RESUMO

A colloidal gold immunochromatographic strip (ICS) for simultaneous detection of multiple transgenic proteins, including CP4 EPSPS, BT-Cry1Ab and BT-Cry1Ac, was developed in this study. The sensitivity of the strip to the target protein was 5 ng/mL for CP4 EPSPS, 100 ng/mL for BT-Cry1Ab and Cry1Ac, respectively. Parallel analysis for maize, soybean, sugar beet and cotton showed the strip could detect 1% of transgenic content in crops containing BT-Cry1Ab and Cry1Ac, and, at least, 0.1% of content in crops containing CP4 EPSPS. The detection results for seed samples indicated the multicomponent analysis ICS had good accuracy. The analysis could be completed within 10 min and had the advantages of being high-throughput, easy to operate and visual detection. This is the first report of semi-quantitative ICS for detecting three transgenic proteins simultaneously. The developed approach may provide insights into the development of ICS for analyzing simultaneously multiple components in genetically modified crops.


Assuntos
Proteínas de Bactérias/análise , Produtos Agrícolas/genética , Endotoxinas/análise , Proteínas Hemolisinas/análise , Imunoensaio/instrumentação , Plantas Geneticamente Modificadas , Animais , Coloide de Ouro/química , Fitas Reagentes , Fatores de Tempo
10.
Pest Manag Sci ; 77(1): 22-32, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32776423

RESUMO

Cytochrome P450s (P450s) have been at the center of herbicide metabolism research as a result of their ability to endow selectivity in crops and resistance in weeds. In the last 20 years, ≈30 P450s from diverse plant species have been revealed to possess herbicide-metabolizing function, some of which were demonstrated to play a key role in plant herbicide sensitivity. Recent research even demonstrated that some P450s from crops and weeds metabolize numerous herbicides from various chemical backbones, which highlights the importance of P450s in the current agricultural systems. However, due to the enormous number of plant P450s and the complexity of their function, expression and regulation, it remains a challenge to fully explore the potential of P450-mediated herbicide metabolism in crop improvement and herbicide resistance mitigation. Differences in the substrate specificity of each herbicide-metabolizing P450 are now evident. Comparisons of the substrate specificity and protein structures of P450s will be beneficial for the discovery of selective herbicides and may lead to the development of crops with higher herbicide tolerance by transgenics or genome-editing technologies. Furthermore, the knowledge will help design sound management strategies for weed resistance including the prediction of cross-resistance patterns. Overcoming the ambiguity of P450 function in plant xenobiotic pathways will unlock the full potential of this enzyme family in advancing global agriculture and food security. © 2020 Society of Chemical Industry.


Assuntos
Herbicidas , Produtos Agrícolas/genética , Sistema Enzimático do Citocromo P-450/genética , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Plantas Daninhas/genética
11.
GM Crops Food ; 12(1): 25-35, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32687427

RESUMO

The importance of food security and nourishment is recognized in Southern African region and in many communities, globally. However, the attainment of food security in Southern African countries is affected by many factors, including adverse environmental conditions, pests and diseases. Scientists have been insistently looking for innovative strategies to optimize crop production and combat challenges militating against attainment of food security. In agriculture, strategies of increasing crop production include but not limited to improved crop varieties, farming practices, extension services, irrigation services, mechanization, information technology, use of fertilizers and agrochemicals. Equally important is genetic modification (GM) technology, which brings new prospects in addressing food security problems. Nonetheless, since the introduction of genetically modified crops (GMOs) three decades ago, it has been a topic of public discourse across the globe, conspicuously so in Southern African region. This is regardless of the evidence that planting GMOs positively influenced farmer's incomes, economic access to food and increased tolerance of crops to various biotic and abiotic stresses. This paper looks at the issues surrounding GMOs adoption in Southern Africa and lack thereof, the discourse, and its potential in contributing to the attainment of food security for the present as well as future generations.


Assuntos
Produtos Agrícolas/genética , Alimentos Geneticamente Modificados , África Austral , Agricultura , Abastecimento de Alimentos , Plantas Geneticamente Modificadas
12.
PLoS One ; 15(11): e0242940, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33253289

RESUMO

Accurate identification of named accessions in germplasm collections is extremely important, especially for vegetatively propagated crops which are expensive to maintain. Thus, an inexpensive, reliable, and rapid genotyping method is essential because it avoids the need for laborious and time-consuming morphological comparisons. Single Nucleotide Polymorphism (SNP) marker panels containing large numbers of SNPs have been developed for many crop species, but such panels are much too large for basic cultivar identification. Here, we have identified a minimum set of SNP markers sufficient to distinguish apple cultivars held in the English and Welsh national collections providing a cheaper and automatable alternative to the markers currently used by the community. We show that SNP genotyping with a small set of well selected markers is equally efficient as microsatellites for the identification of apple cultivars and has the added advantage of automation and reduced cost when screening large numbers of samples.


Assuntos
Genoma de Planta/genética , Malus/genética , Repetições de Microssatélites/genética , Polimorfismo de Nucleotídeo Único/genética , Alelos , Cruzamento , Produtos Agrícolas/genética , Genótipo , Humanos , Malus/classificação , Banco de Sementes/classificação
13.
Proc Natl Acad Sci U S A ; 117(43): 26849-26853, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33046649

RESUMO

Pesticides are a ubiquitous component of conventional crop production but come with considerable economic and ecological costs. We tested the hypothesis that variation in pesticide use among crop species is a function of crop economics and the phylogenetic relationship of a crop to native plants because unrelated crops accrue fewer herbivores and pathogens. Comparative analyses of a dataset of 93 Californian crops showed that more valuable crops and crops with close relatives in the native plant flora received greater pesticide use, explaining roughly half of the variance in pesticide use among crops against pathogens and herbivores. Phylogenetic escape from arthropod and pathogen pests results in lower pesticides, suggesting that the introduced status of some crops can be leveraged to reduce pesticides.


Assuntos
Agricultura/estatística & dados numéricos , Artrópodes , Produtos Agrícolas/genética , Ecossistema , Praguicidas , Animais , California , Filogenia
14.
Sci Rep ; 10(1): 18532, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33116201

RESUMO

Ethiopia is the largest wheat producer in sub-Saharan Africa yet remains a net importer. Increasing domestic wheat production is a national priority. Improved varieties provide an important pathway to enhancing productivity and stability of production. Reliably tracking varietal use and dynamics is a challenge, and the value of conventional recall surveys is increasingly questioned. We report the first nationally representative, large-scale wheat DNA fingerprinting study undertaken in Ethiopia. Plot level comparison of DNA fingerprinting with farmer recall from nearly 4000 plots in the 2016/17 season indicates that only 28% of farmers correctly named wheat varieties grown. The DNA study reveals that new, rust resistant bread wheat varieties are now widely adopted. Germplasm originating from CGIAR centres has made a significant contribution. Corresponding productivity gains and economic benefits have been substantial, indicating high returns to investments in wheat improvement. The study provides an accurate assessment of wheat varietal status and sets a benchmark for national policy-makers and donors. In recent decades, the Ethiopian wheat landscape has transformed from local tetraploid varieties to widespread adoption of high yielding, rust resistant bread wheat. We demonstrate that DNA fingerprinting can be applied at scale and is likely to transform future crop varietal adoption studies.


Assuntos
Agricultura/métodos , Impressões Digitais de DNA/métodos , Triticum/genética , Produtos Agrícolas/genética , Etiópia , Fazendeiros/educação
15.
Nat Biotechnol ; 38(10): 1203-1210, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33020633

RESUMO

Wild and weedy relatives of domesticated crops harbor genetic variants that can advance agricultural biotechnology. Here we provide a genome resource for the wild plant green millet (Setaria viridis), a model species for studies of C4 grasses, and use the resource to probe domestication genes in the close crop relative foxtail millet (Setaria italica). We produced a platinum-quality genome assembly of S. viridis and de novo assemblies for 598 wild accessions and exploited these assemblies to identify loci underlying three traits: response to climate, a 'loss of shattering' trait that permits mechanical harvest and leaf angle, a predictor of yield in many grass crops. With CRISPR-Cas9 genome editing, we validated Less Shattering1 (SvLes1) as a gene whose product controls seed shattering. In S. italica, this gene was rendered nonfunctional by a retrotransposon insertion in the domesticated loss-of-shattering allele SiLes1-TE (transposable element). This resource will enhance the utility of S. viridis for dissection of complex traits and biotechnological improvement of panicoid crops.


Assuntos
Genoma de Planta/genética , Milhetes/genética , Proteínas de Plantas/genética , Setaria (Planta)/genética , Alelos , Sistemas CRISPR-Cas/genética , Produtos Agrícolas/genética , Elementos de DNA Transponíveis/genética , Domesticação , Grão Comestível/genética , Edição de Genes , Genótipo , Fenótipo , Filogenia
16.
Nat Commun ; 11(1): 5203, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060603

RESUMO

Ending all forms of hunger by 2030, as set forward in the UN-Sustainable Development Goal 2 (UN-SDG2), is a daunting but essential task, given the limited timeline ahead and the negative global health and socio-economic impact of hunger. Malnutrition or hidden hunger due to micronutrient deficiencies affects about one third of the world population and severely jeopardizes economic development. Staple crop biofortification through gene stacking, using a rational combination of conventional breeding and metabolic engineering strategies, should enable a leap forward within the coming decade. A number of specific actions and policy interventions are proposed to reach this goal.


Assuntos
Biofortificação/métodos , Engenharia Metabólica/métodos , Cruzamento , Produtos Agrícolas/genética , Países em Desenvolvimento , Abastecimento de Alimentos , Alimentos Fortificados , Saúde Global , Humanos , Desnutrição/prevenção & controle , Micronutrientes , Minerais , Oryza , Plantas/genética , Plantas Geneticamente Modificadas , Formulação de Políticas , Provitaminas , Desenvolvimento Sustentável/economia , Desenvolvimento Sustentável/tendências , Nações Unidas , Vitaminas
17.
PLoS One ; 15(10): e0239122, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33031381

RESUMO

Cowpea [Vigna unguiculata (L.) Walp] is one of the important climate-resilient legume crops for food and nutrition security in sub-Saharan Africa. Ethiopia is believed to harbor high cowpea genetic diversity, but this has not yet been efficiently characterized and exploited in breeding. The objective of this study was to evaluate the extent and pattern of genetic diversity in 357 cowpea accestions comprising landraces (87%), breeding lines (11%) and released varieties (2%), using single nucleotide polymorphism markers. The overall gene diversity and heterozygosity were 0.28 and 0.12, respectively. The genetic diversity indices indicated substantial diversity in Ethiopian cowpea landraces. Analysis of molecular variance showed that most of the variation was within in the population (46%) and 44% between individuals, with only 10% of the variation being among populations. Model-based ancestry analysis, the phylogenetic tree, discriminant analysis of principal components and principal coordinate analysis classified the 357 genotypes into three well-differentiated genetic populations. Genotypes from the same region grouped into different clusters, while others from different regions fell into the same cluster. This indicates that differences in regions of origin may not be the main driver determining the genetic diversity in cowpea in Ethiopia. Therefore, differences in sources of origin, as currently distributed in Ethiopia, should not necessarily be used as indices of genetic diversity. Choice of parental lines should rather be based on a systematic assessment of genetic diversity in a specific population. The study also suggested 94 accesstions as core collection which retained 100% of the genetic diversity from the entire collection. This core set represents 26% of the entire collection pinpointing a wide distribution of the diversity within the ethiopian landraces. The outcome of this study provided new insights into the genetic diversity and population structure in Ethiopian cowpea genetic resources for designing effective collection and conservation strategies for efficient utilization in breeding.


Assuntos
Vigna/genética , Produtos Agrícolas/genética , DNA de Plantas/genética , Etiópia , Marcadores Genéticos , Variação Genética , Filogenia , Filogeografia , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único , Vigna/classificação
18.
Sci Rep ; 10(1): 15733, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978485

RESUMO

The transmission of pollen is the main cause of maize gene flow. Under the compulsory labeling system for genetically modified (GM) products in China, isolation measures are crucial. At present, there is no effective isolation device for preventing and controlling the short-range flow of GM maize pollen. The purposes of the present experiments were to overcome the deficiencies of existing technology and to demonstrate a new isolation device for decreasing the gene flow distance of GM maize. The isolation device we invented was shown to be more robust than traditional isolation methods, and it can be disassembled and repeatedly reused. The most important point was that the frequency of gene flow could be greatly reduced using this device. When the distance from the isolation device was more than 1 m, the gene flow rate could be decreased to less than 1%, and when the distance from the isolation device was more than 10 m, the gene flow rate could be reduced to less than 0.1%. When the isolation device was adopted to isolate GM maize in conjunction with bagging the tassels of GM maize at the pollination stage, the gene flow could be controlled to less than 0.1% when the distance from the isolation device was more than 1 m. This device was, however, only applicable for small plots and can shorten the isolation distance of GM maize planting and improve the purity of seeds, all while meeting the needs of close isolation breeding. The use of this device represents a feasible method for risk prevention and control of GM crops.


Assuntos
Agricultura/métodos , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimento , China , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Fluxo Gênico , Melhoramento Vegetal , Polinização , Zea mays/genética
19.
Nat Commun ; 11(1): 4876, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978378

RESUMO

In most crops, genetic and environmental factors interact in complex ways giving rise to substantial genotype-by-environment interactions (G×E). We propose that computer simulations leveraging field trial data, DNA sequences, and historical weather records can be used to tackle the longstanding problem of predicting cultivars' future performances under largely uncertain weather conditions. We present a computer simulation platform that uses Monte Carlo methods to integrate uncertainty about future weather conditions and model parameters. We use extensive experimental wheat yield data (n = 25,841) to learn G×E patterns and validate, using left-trial-out cross-validation, the predictive performance of the model. Subsequently, we use the fitted model to generate circa 143 million grain yield data points for 28 wheat genotypes in 16 locations in France, over 16 years of historical weather records. The phenotypes generated by the simulation platform have multiple downstream uses; we illustrate this by predicting the distribution of expected yield at 448 cultivar-location combinations and performing means-stability analyses.


Assuntos
Simulação por Computador , Produtos Agrícolas/genética , Genótipo , Incerteza , Tempo (Meteorologia) , Agricultura/métodos , DNA de Plantas , Grão Comestível/genética , França , Interação Gene-Ambiente , Modelos Genéticos , Fenótipo , Triticum/genética
20.
Plant Biotechnol J ; 18(12): 2388-2405, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32875704

RESUMO

Agricultural production faces a Herculean challenge to feed the increasing global population. Food production systems need to deliver more with finite land and water resources while exerting the least negative influence on the ecosystem. The unpredictability of climate change and consequent changes in pests/pathogens dynamics aggravate the enormity of the challenge. Crop improvement has made significant contributions towards food security, and breeding climate-smart cultivars are considered the most sustainable way to accelerate food production. However, a fundamental change is needed in the conventional breeding framework in order to respond adequately to the growing food demands. Progress in genomics has provided new concepts and tools that hold promise to make plant breeding procedures more precise and efficient. For instance, reference genome assemblies in combination with germplasm sequencing delineate breeding targets that could contribute to securing future food supply. In this review, we highlight key breakthroughs in plant genome sequencing and explain how the presence of these genome resources in combination with gene editing techniques has revolutionized the procedures of trait discovery and manipulation. Adoption of new approaches such as speed breeding, genomic selection and haplotype-based breeding could overcome several limitations of conventional breeding. We advocate that strengthening varietal release and seed distribution systems will play a more determining role in delivering genetic gains at farmer's field. A holistic approach outlined here would be crucial to deliver steady stream of climate-smart crop cultivars for sustainable agriculture.


Assuntos
Produtos Agrícolas , Ecossistema , Agricultura , Produtos Agrícolas/genética , Genoma de Planta/genética , Genômica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA