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1.
Methods Mol Biol ; 2287: 267-279, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34270036

RESUMO

The intergeneric hybridization of wheat (Triticum aestivum L.) with maize (Zea mays L.) enables the production of doubled haploids (DHs) of wheat from all wheat hybrids with high efficiencies. Wheat and maize donor plants are raised in environmentally controlled greenhouses until crossing. Before anthesis, wheat spikes are emasculated and then pollinated with maize. Auxin is applied to each individual wheat floret 1 day after pollination. About 2 weeks after crossing, in vitro embryo culture is performed, enabling the regeneration of haploid wheat plantlets after maize chromosome elimination. Haploid plantlets are transferred to the greenhouse and after recovery, their genome is doubled with colchicine. Haploid plantlets can be sampled for DNA extractions and molecular analyses to aid the rapid discard of undesirable plantlets. Doubled haploid plants are raised in a greenhouse until maturity. Seeds of each fertile DH are harvested and often sown the same year. Several cycles of multiplication and evaluation in replicated plot trials and different geographical locations are then done to select the best candidate(s) for varietal registration.


Assuntos
Hibridização Genética , Melhoramento Vegetal/métodos , Triticum/crescimento & desenvolvimento , Triticum/genética , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Cruzamentos Genéticos , Haploidia , Sementes/genética , Sementes/crescimento & desenvolvimento
2.
Biology (Basel) ; 10(5)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068451

RESUMO

There is an urgent need to increase and improve the production of most agronomic species to meet the current food security challenge [...].

3.
Theor Appl Genet ; 132(11): 3063-3078, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31485698

RESUMO

KEY MESSAGE: The comparison of QTL detection performed on an elite panel and an (elite [Formula: see text] exotic) progeny shows that introducing exotic germplasm into breeding programs can bring new interesting allelic diversity. Selection of stable varieties producing the highest amount of extractable sugar per hectare (ha), resistant to diseases, and respecting environmental criteria is undoubtedly the main target for sugar beet breeding. As sodium, potassium, and [Formula: see text]-amino nitrogen in sugar beets are the impurities that have the biggest negative impact on white sugar extraction, it is interesting to reduce their concentration in further varieties. However, domestication history and strong selection pressures have affected the genetic diversity needed to achieve this goal. In this study, quantitative trait locus (QTL) detection was performed on two populations, an (elite [Formula: see text] exotic) sugar beet progeny and an elite panel, to find potentially new interesting regions brought by the exotic accession. The three traits linked with impurities content were studied. Some QTLs were detected in both populations, the majority in the elite panel because of most statistical power. Some of the QTLs were colocated and had favorable effect in the progeny since the exotic allele was linked with a decrease in the impurity content. A few number of favorable QTLs were detected in the progeny, only. Consequently, introgressing exotic genetic material into sugar beet breeding programs can allow the incorporation of new interesting alleles.


Assuntos
Beta vulgaris/genética , Melhoramento Vegetal , Locos de Características Quantitativas , Açúcares/química , Alelos , Beta vulgaris/química , Mapeamento Cromossômico , Genótipo , Modelos Genéticos , Nitrogênio , Fenótipo , Polimorfismo de Nucleotídeo Único , Potássio , Sódio
4.
Transgenic Res ; 28(Suppl 2): 65-73, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31321686

RESUMO

The large French research project GENIUS (2012-2019, https://www6.inra.genius-project_eng/ ) provides a good showcase of current genome editing techniques applied to crop plants. It addresses a large variety of agricultural species (rice, wheat, maize, tomato, potato, oilseed rape, poplar, apple and rose) together with some models (Arabidopsis, Brachypodium, Physcomitrella). Using targeted mutagenesis as its work horse, the project is limited to proof of concept under confined conditions. It mainly covers traits linked to crop culture, such as disease resistance to viruses and fungi, flowering time, plant architecture, tolerance to salinity and plant reproduction but also addresses traits improving the quality of agricultural products for industrial purposes. Examples include virus resistant tomato, early flowering apple and low-amylose starch potato. The wide range of traits illustrates the potential of genome editing towards a more sustainable agriculture through the reduction of pesticides and to the emergence of innovative bio-economy sectors based on custom tailored quality traits.


Assuntos
Agricultura/tendências , Sistemas CRISPR-Cas/genética , Produtos Agrícolas/genética , Edição de Genes/métodos , Animais , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Brachypodium/genética , Brachypodium/crescimento & desenvolvimento , Bryopsida/genética , Bryopsida/crescimento & desenvolvimento , Produtos Agrícolas/crescimento & desenvolvimento , Genoma de Planta/genética , Mutagênese/genética , Fenótipo
5.
Plant Cell Rep ; 38(9): 1065-1080, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31101972

RESUMO

KEY MESSAGE: The StGBSSI gene was successfully and precisely edited in the tetraploid potato using gene and base-editing strategies, leading to plants with impaired amylose biosynthesis. Genome editing has recently become a method of choice for basic research and functional genomics, and holds great potential for molecular plant-breeding applications. The powerful CRISPR-Cas9 system that typically produces double-strand DNA breaks is mainly used to generate knockout mutants. Recently, the development of base editors has broadened the scope of genome editing, allowing precise and efficient nucleotide substitutions. In this study, we produced mutants in two cultivated elite cultivars of the tetraploid potato (Solanum tuberosum) using stable or transient expression of the CRISPR-Cas9 components to knock out the amylose-producing StGBSSI gene. We set up a rapid, highly sensitive and cost-effective screening strategy based on high-resolution melting analysis followed by direct Sanger sequencing and trace chromatogram analysis. Most mutations consisted of small indels, but unwanted insertions of plasmid DNA were also observed. We successfully created tetra-allelic mutants with impaired amylose biosynthesis, confirming the loss of function of the StGBSSI protein. The second main objective of this work was to demonstrate the proof of concept of CRISPR-Cas9 base editing in the tetraploid potato by targeting two loci encoding catalytic motifs of the StGBSSI enzyme. Using a cytidine base editor (CBE), we efficiently and precisely induced DNA substitutions in the KTGGL-encoding locus, leading to discrete variation in the amino acid sequence and generating a loss-of-function allele. The successful application of base editing in the tetraploid potato opens up new avenues for genome engineering in this species.


Assuntos
Edição de Genes , Solanum tuberosum/genética , Sintase do Amido/genética , Alelos , Sistemas CRISPR-Cas , Tetraploidia
6.
Mol Ecol ; 27(13): 2823-2833, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29772088

RESUMO

Genome-environment association methods aim to detect genetic markers associated with environmental variables. The detected associations are usually analysed separately to identify the genomic regions involved in local adaptation. However, a recent study suggests that single-locus associations can be combined and used in a predictive way to estimate environmental variables for new individuals on the basis of their genotypes. Here, we introduce an original approach to predict the environmental range (values and upper and lower limits) of species genotypes from the genetic markers significantly associated with those environmental variables in an independent set of individuals. We illustrate this approach to predict aridity in a database constituted of 950 individuals of wild beets and 299 individuals of cultivated beets genotyped at 14,409 random single nucleotide polymorphisms (SNPs). We detected 66 alleles associated with aridity and used them to calculate the fraction (I) of aridity-associated alleles in each individual. The fraction I correctly predicted the values of aridity in an independent validation set of wild individuals and was then used to predict aridity in the 299 cultivated individuals. Wild individuals had higher median values and a wider range of values of aridity than the cultivated individuals, suggesting that wild individuals have higher ability to resist to stress-aridity conditions and could be used to improve the resistance of cultivated varieties to aridity.


Assuntos
Adaptação Fisiológica/genética , Interação Gene-Ambiente , Marcadores Genéticos , Genética Populacional , Alelos , Genoma/genética , Genômica , Genótipo , Metagenômica , Modelos Genéticos , Polimorfismo de Nucleotídeo Único/genética
7.
Theor Appl Genet ; 130(9): 1857-1866, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28589246

RESUMO

KEY MESSAGE: Using a much higher number of SNP markers and larger sample sizes than all the previous studies, we characterized the genetic relationships among wild and cultivated plants of section Beta. We analyzed the genetic variation of Beta section Beta, which includes wild taxa (Beta macrocarpa, B. patula, B. vulgaris subsp. adanensis and B. vulgaris subsp. maritima) and cultivars (fodder beet, sugar beet, garden beet, leaf beet, and swiss chards), using 9724 single nucleotide polymorphism markers. The analyses conducted at the individual level without a priori groups confirmed the strong differentiation of B. macrocarpa and B. vulgaris subsp. adanensis from the other taxa. B. vulgaris subsp. maritima showed a complex genetic structure partly following a geographical pattern, which confounded the differences between this taxon and the cultivated varieties. Cultivated varieties were structured into three main groups: garden beets, fodder and sugar beets, and leaf beets and swiss chards. The genetic structure described here will be helpful to correctly estimate linkage disequilibrium and to test for statistical associations between genetic markers and environmental variables.


Assuntos
Beta vulgaris/classificação , Genética Populacional , Polimorfismo de Nucleotídeo Único , Beta vulgaris/genética , Marcadores Genéticos , Desequilíbrio de Ligação
8.
Plant Genome ; 9(1)2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-27898760

RESUMO

Transposable elements (TEs) account for more than 80% of the wheat genome. Although they represent a major obstacle for genomic studies, TEs are also a source of polymorphism and consequently of molecular markers such as insertion site-based polymorphism (ISBP) markers. Insertion site-based polymorphisms have been found to be a great source of genome-specific single-nucleotide polymorphism (SNPs) in the hexaploid wheat ( L.) genome. Here, we report on the development of a high-throughput SNP discovery approach based on sequence capture of ISBP markers. By applying this approach to the reference sequence of chromosome 3B from hexaploid wheat, we designed 39,077 SNPs that are evenly distributed along the chromosome. We demonstrate that these SNPs can be efficiently scored with the KASPar (Kompetitive allele-specific polymerase chain reaction) genotyping technology. Finally, through genetic diversity and genome-wide association studies, we also demonstrate that ISBP-derived SNPs can be used in marker-assisted breeding programs.


Assuntos
Genoma de Planta , Técnicas de Genotipagem/métodos , Polimorfismo de Nucleotídeo Único/genética , Sequências Repetitivas de Ácido Nucleico/genética , Triticum/genética , Estudo de Associação Genômica Ampla , Genótipo , Triticum/classificação
9.
Theor Appl Genet ; 129(2): 257-71, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26526552

RESUMO

KEY MESSAGE: The genetic variation of Beta section Beta is structured into four taxonomic and spatial clusters. There are significant associations between molecular markers and environmental variables. ABSTRACT: We investigated the genetic diversity of Beta section Beta, which includes the wild and cultivated relatives of the sugar beet. The taxa included in the study were: Beta vulgaris subsp. maritima, B. vulgaris subsp. adanensis, B. macrocarpa, B. patula and B. vulgaris subsp. vulgaris (garden beet, leaf beet and swiss chards). We collected 1264 accessions originating from the entire distribution area of these taxa and genotyped them for 4436 DArT markers (DArTs). We showed that the genetic variation of these accessions is structured into four taxonomic and spatial clusters: (1) samples of Beta macrocarpa, (2) samples of Beta vulgaris subsp. adanensis, (3) Mediterranean and Asian samples and (4) Atlantic and Northern European samples. These last two clusters were mainly composed of samples of Beta vulgaris subsp. maritima. We investigated in deeper detail the genetic structure of B. vulgaris subsp. maritima, which constituted the majority (80%) of the wild samples. This subspecies exhibited a clinal genetic variation from South-East to North-West. We detected some markers significantly associated to environmental variables in B. vulgaris subsp. maritima. These associations are interpreted as results of natural selection. The variable most often involved in the associations was annual mean temperature. Therefore, these markers can be useful for the development of frost-tolerant winter beets and drought-tolerant rain-fed beets.


Assuntos
Adaptação Biológica/genética , Beta vulgaris/genética , Variação Genética , Teorema de Bayes , Chenopodiaceae/genética , Análise por Conglomerados , Produtos Agrícolas/genética , DNA de Plantas/genética , Interação Gene-Ambiente , Marcadores Genéticos , Genética Populacional , Genótipo , Modelos Lineares , Modelos Genéticos , Análise de Componente Principal
10.
Theor Appl Genet ; 128(11): 2255-71, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26239407

RESUMO

KEY MESSAGE: Genetic diversity in worldwide population of beets is strongly affected by the domestication history, and the comparison of linkage disequilibrium in worldwide and elite populations highlights strong selection pressure. Genetic relationships and linkage disequilibrium (LD) were evaluated in a set of 2035 worldwide beet accessions and in another of 1338 elite sugar beet lines, using 320 and 769 single nucleotide polymorphisms, respectively. The structures of the populations were analyzed using four different approaches. Within the worldwide population, three of the methods gave a very coherent picture of the population structure. Fodder beet and sugar beet accessions were grouped together, separated from garden beets and sea beets, reflecting well the origins of beet domestication. The structure of the elite panel, however, was less stable between clustering methods, which was probably because of the high level of genetic mixing in breeding programs. For the linkage disequilibrium analysis, the usual measure (r (2)) was used, and compared with others that correct for population structure and relatedness (r S (2) , r V (2) , r VS (2)). The LD as measured by r (2) persisted beyond 10 cM within the elite panel and fell below 0.1 after less than 2 cM in the worldwide population, for almost all chromosomes. With correction for relatedness, LD decreased under 0.1 by 1 cM for almost all chromosomes in both populations, except for chromosomes 3 and 9 within the elite panel. In these regions, the larger extent of LD could be explained by strong selection pressure.


Assuntos
Beta vulgaris/genética , Ligação Genética , Desequilíbrio de Ligação , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único , Beta vulgaris/classificação , Impressões Digitais de DNA , DNA de Plantas/genética , Genética Populacional , Genótipo , Modelos Genéticos , Seleção Genética
11.
Plant Cell Rep ; 28(9): 1329-39, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19529940

RESUMO

Albinism remains a major problem in cereal improvement programs that rely on doubled haploid (DH) technology, and the factors controlling the phenomenon are not well understood. Here we report on the positive influence of copper on the production of DH plants obtained through microspore embryogenesis (ME) in recalcitrant cultivars of barley (Hordeum vulgare L.). The presence of copper sulphate in the anther pre-treatment medium improved green DH plant regeneration from cultivars known to produce exclusively albino plants using classical procedures. In plastids, the effect of copper was characterized by a decrease in starch and a parallel increase in internal membranes. The addition of copper sulphate in the ME pre-treatment medium should enable breeders to exploit the genetic diversity of recalcitrant cultivars through DH technology. We examined programmed cell death (PCD) during microspore development to determine whether PCD may interfere with the induction of ME and/or the occurrence of albinism. By examining the fate of nuclei in various anther cell layers, we demonstrated that the kinetics of PCD in anthers differed between the barley cultivars Igri and Cork that show a low and a high rate of albinism, respectively. However, no direct correlation between PCD in the anther cell layers and the rate of albinism was observed and copper had no influence on the PCD kinetic in these cultivars. It was concluded that albinism following ME was not due to PCD in anthers, but rather to another unknown phenomenon that appears to specifically affect plastids during microspore/pollen development.


Assuntos
Apoptose , Sulfato de Cobre/farmacologia , Hordeum/efeitos dos fármacos , Hordeum/embriologia , Pigmentação/efeitos dos fármacos , Técnicas de Cultura de Células , Meios de Cultura/farmacologia , DNA de Plantas/efeitos dos fármacos , Desenvolvimento Embrionário , Haploidia , Plastídeos/efeitos dos fármacos , Plastídeos/ultraestrutura , Regeneração
12.
Planta ; 229(2): 393-402, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18974997

RESUMO

Microspore embryogenesis (ME) is a process in which the gametophytic pollen programme of the microspore is reoriented towards a new embryo sporophytic programme. This process requires a stress treatment, usually performed in the anther or isolated microspores for several days. Despite the universal use of stress to induce ME, very few studies have addressed the physiological processes that occur in the anther during this step. To further understand the processes triggered by stress treatment, we followed the response of anthers by measuring the expression of stress-related genes in two barley (Hordeum vulgare L.) cultivars differing in their ME response. Genes encoding enzymes involved in oxidative stress (glutathione-S-transferase, GST; oxalate oxidase, OxO), in the synthesis of jasmonic acid (13-lipoxygenase, Lox; allene oxide cyclase, AOC; allene oxide synthase, AOS) and in the phenylpropanoid pathway (phenylalanine ammonia lyase, PAL), as well as those encoding PR proteins (Barwin, chitinase 2b, Chit 2b; glucanase, Gluc; basic pathogenesis-related protein 1, PR1; pathogenesis-related protein 10, PR10) were up-regulated in whole anthers upon stress treatment, indicating that anther perceives stress and reacts by triggering general plant defence mechanisms. In particular, both OxO and Chit 2b genes are good markers of anther reactivity owing to their high level of induction during the stress treatment. The effect of copper sulphate appeared to limit the expression of defence-related genes, which may be correlated with its positive effect on the yield of microspore embryos.


Assuntos
Desenvolvimento Embrionário , Regulação da Expressão Gênica de Plantas , Hordeum/embriologia , Hordeum/imunologia , Pólen/embriologia , Pólen/genética , Ciclopentanos/metabolismo , Genes de Plantas , Hordeum/enzimologia , Hordeum/genética , Estresse Oxidativo/genética , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pólen/citologia , Pólen/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxidos/metabolismo
13.
J Plant Physiol ; 161(6): 747-55, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15266723

RESUMO

Sugars and polyols were tested at different steps of anther culture in barley (Hordeum vulgare L.) to elucidate their influence on both the overall yield of androgenesis and the structure of plastids in relation to albinism. During the pretreatment period, the osmotic regulation in the medium was beneficial to microspore embryogenesis regardless of the type and concentration of the tested osmoticum. The use of mannitol (300 mOsm/kg), sorbitol (180 mOsm/kg), PEG (240 mOsm/kg) and sucrose (180 mOsm/kg) gave the best results in terms of green plant production, although the influence of each substance differed according to the studied parameter. Similarly, during anther culture the regulation of the osmotic pressure in the medium had various effects, according to the osmoticum used. The best results were obtained using mannitol (364 mOsm/kg), providing 139.7 green plants per 100 plated anthers. Plastids were examined by electron microscopy following both pretreatment and culture. In the presence of mannitol and PEG, plastids did not accumulate starch at any stage of the protocol but they started to differentiate into chloroplasts in the microspore-derived embryos. Using sorbitol and sucrose, plastids differentiated poorly but accumulated large amounts of starch, suggesting that these sugars are metabolized by micropores and microspore derived structures. However, the accumulation of starch was not correlated with the occurrence of albinism. These results indicated that, in barley, the osmotic regulation was favourable to switch the microspore gametophytic program toward a sporophytic program regardless of the nature of the osmoticum. In addition, during the pretreatment period, mannito was found to be the most suitable osmoticum for subsequent embryo development.


Assuntos
Hordeum/crescimento & desenvolvimento , Hordeum/genética , Plastídeos/fisiologia , Hordeum/efeitos dos fármacos , Hordeum/ultraestrutura , Manitol/farmacologia , Microscopia Eletrônica , Concentração Osmolar , Plastídeos/efeitos dos fármacos , Plastídeos/ultraestrutura , Estações do Ano , Sorbitol/farmacologia , Sacarose/farmacologia
14.
Buenos Aires; Librería Hachette; nov.1950. 268 p. (Colección Saber, 9). (81609).
Monografia em Espanhol | BINACIS | ID: bin-81609
15.
Buenos Aires; Librería Hachette; nov.1950. 268 p. (Colección Saber, 9).
Monografia em Espanhol | LILACS-Express | BINACIS | ID: biblio-1204119
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