Cappelle-en-Pévèle, France
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Azzimonti G.,French National Institute for Agricultural Research | Marcel T.C.,French National Institute for Agricultural Research | Robert O.,Florimond Desprez | Paillard S.,CNRS Institute of Genetics, Environment and Plant Protection | And 2 more authors.
Molecular Breeding | Year: 2014

Quantitative resistance is generally associated with several genes, located in quantitative trait loci (QTLs). Although often described as non-isolate-specific and durable, some cases of erosion of this resistance have been observed. The likelihood of an erosion of quantitative resistance could be reduced, provided that this resistance rests on diversified mechanisms. We hypothesized that QTLs phenotypically expressed on different components, govern different mechanisms of resistance. A doubled haploid population of 91 lines, derived from a cross between the wheat cultivars Apache and Balance, was used to identify leaf rust resistance QTLs. After establishing a linkage map with 355 markers, 13 QTLs were found involved in field resistance, for over 2 years in two locations. Ten of these QTLs were associated with five resistance components (infection efficiency, latent period, lesion size, spore production per lesion and spore production per unit of sporulating tissue) measured in two greenhouse experiments. All but one of the QTLs found in the greenhouse were associated with one or two resistance components, supporting the hypothesis that different genetic factors are mostly involved in the expression of different resistance components. Analyzing separately different field scoring dates revealed QTLs involved at different stages of the epidemic. The QTLs displayed different degrees of isolate-specificity on field resistance, as measured by LOD scores and R2, leading to the conclusion that isolate-specificity is both a qualitative and quantitative feature of quantitative resistance. A profile of each QTL was drawn, to evaluate its usefulness according to the objectives of the breeding program. © 2014 European Union.


Andrello M.,CNRS Center of Evolutionary and Functional Ecology | Henry K.,Florimond Desprez | Devaux P.,Florimond Desprez | Desprez B.,Florimond Desprez | Manel S.,CNRS Center of Evolutionary and Functional Ecology
Theoretical and Applied Genetics | Year: 2016

Key message: The genetic variation of BetasectionBetais 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. © 2015, Springer-Verlag Berlin Heidelberg.


PubMed | CNRS Center of Evolutionary and Functional Ecology and Florimond Desprez
Type: Journal Article | Journal: TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik | Year: 2016

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.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.


PubMed | Polytechnic Institute of LaSalle Beauvais, Leroux SAS, Institut Universitaire de France and Florimond Desprez
Type: Journal Article | Journal: Journal of agricultural and food chemistry | Year: 2015

During the heat treatment of coffee and its substitutes some compounds potentially deleterious to health are synthesized by the Maillard reaction. Among these, N()-carboxymethyl-lysine (CML) was detected at high levels in coffee substitutes. The objective of this study was to evaluate the impact of changes in agricultural practice on the lysine content present in chicory roots and try to limit CML formation during roasting. Of the 24 varieties analyzed, small variations in lysine content were observed, 213 8 mg/100 g dry matter (DM). The formation of lysine tested in five commercial varieties was affected by the nitrogen treatment with mean levels of 176 2 mg/100 g DM when no fertilizer was added and 217 7 mg/100 g DM with a nitrogen supply of 120 kg/ha. The lysine content of fresh roots was significantly correlated to the concentration of CML formed in roasted roots (r = 0.51; p < 0.0001; n = 76).


Tabib Ghaffary S.M.,Plant Research International | Robert O.,Bioplante | Laurent V.,Bioplante | Lonnet P.,Florimond Desprez | And 4 more authors.
Theoretical and Applied Genetics | Year: 2011

The ascomycete Mycosphaerella graminicola is the causal agent of septoria tritici blotch (STB), one of the most destructive foliar diseases of bread and durum wheat globally, particularly in temperate humid areas. A screening of the French bread wheat cultivars Apache and Balance with 30 M. graminicola isolates revealed a pattern of resistant responses that suggested the presence of new genes for STB resistance. Quantitative trait loci (QTL) analysis of a doubled haploid (DH) population with five M. graminicola isolates in the seedling stage identified four QTLs on chromosomes 3AS, 1BS, 6DS and 7DS, and occasionally on 7DL. The QTL on chromosome 6DS flanked by SSR markers Xgpw5176 and Xgpw3087 is a novel QTL that now can be designated as Stb18. The QTLs on chromosomes 3AS and 1BS most likely represent Stb6 and Stb11, respectively, and the QTLs on chromosome 7DS are most probably identical with Stb4 and Stb5. However, the QTL identified on chromosome 7DL is expected to be a new Stb gene that still needs further characterization. Multiple isolates were used and show that not all isolates identify all QTLs, which clearly demonstrates the specificity in the M. graminicola-wheat pathosystem. QTL analyses were performed with various disease parameters. The development of asexual fructifications (pycnidia) in the characteristic necrotic blotches of STB, designated as parameter P, identified the maximum number of QTLs. All other parameters identified fewer but not different QTLs. The segregation of multiple QTLs in the Apache/Balance DH population enabled the identification of DH lines with single QTLs and multiple QTL combinations. Analyses of the marker data of these DH lines clearly demonstrated the positive effect of pyramiding QTLs to broaden resistance spectra as well as epistatic and additive interactions between these QTLs. Phenotyping of the Apache/Balance DH population in the field confirmed the presence of the QTLs that were identified in the seedling stage, but Stb18 was inconsistently expressed and might be particularly effective in young plants. In contrast, an additional QTL for STB resistance was identified on chromosome 2DS that is exclusively and consistently expressed in mature plants over locations and time, but it was also strongly related with earliness, tallness as well as resistance to Fusarium head blight. Although to date no Stb gene has been reported on chromosome 2D, the data provide evidence that this QTL is only indirectly related to STB resistance. This study shows that detailed genetic analysis of contemporary commercial bread wheat cultivars can unveil novel Stb genes that can be readily applied in marker-assisted breeding programs. © The Author(s) 2011.


Prat N.,University of Natural Resources and Life Sciences, Vienna | Guilbert C.,University of Natural Resources and Life Sciences, Vienna | Prah U.,University of Natural Resources and Life Sciences, Vienna | Wachter E.,University of Natural Resources and Life Sciences, Vienna | And 4 more authors.
Theoretical and Applied Genetics | Year: 2016

Key message: The QTL Fhb1was successfully introgressed and validated in three durum wheat populations. The novel germplasm and the QTL detected will support improvement of Fusarium resistance in durum wheat.Abstract: Durum wheat (Triticum durum Desf.) is particularly susceptible to Fusarium head blight (FHB) and breeding for resistance is hampered by limited genetic variation within this species. To date, resistant sources are mainly available in a few wild relative tetraploid wheat accessions. In this study, the effect of the well-known hexaploid wheat (Triticum aestivum L.) quantitative trait locus (QTL) Fhb1 was assessed for the first time in durum wheat. Three F7-RIL mapping populations of about 100 lines were developed from crosses between the durum wheat experimental line DBC-480, which carries an Fhb1 introgression from Sumai-3, and the European T. durum cultivars Karur, Durobonus and SZD1029K. The RILs were evaluated in field experiments for FHB resistance in three seasons using spray inoculation and genotyped with SSR as well as genotyping-by-sequencing markers. QTL associated with FHB resistance were identified on chromosome arms 2BL, 3BS, 4AL, 4BS, 5AL and 6AS at which the resistant parent DBC-480 contributed the positive alleles. The QTL on 3BS was detected in all three populations centered at the Fhb1 interval. The Rht-B1 locus governing plant height was found to have a strong effect in modulating FHB severity in all populations. The negative effect of the semi-dwarf allele Rht-B1b on FHB resistance was compensated by combining with Fhb1 and additional resistance QTL. The successful deployment of Fhb1 in T. durum was further substantiated by assessing type 2 resistance in one population. The efficient introgression of Fhb1 represents a significant step forward for enhancing FHB resistance in durum wheat. © 2016 The Author(s)


Prat N.,University of Natural Resources and Life Sciences, Vienna | Prat N.,University Blaise Pascal | Buerstmayr M.,University of Natural Resources and Life Sciences, Vienna | Steiner B.,University of Natural Resources and Life Sciences, Vienna | And 2 more authors.
Molecular Breeding | Year: 2014

Fusarium head blight (FHB) is a serious threat worldwide due to its dramatic consequences and effects on small grain cereal production such as yield and quality losses and most importantly mycotoxin contamination. Durum wheat (Triticum durum Desf.) is particularly susceptible to FHB. Enhancing resistance has proven difficult due to the narrow genetic variation for this trait in the durum wheat gene pool. Broadening the genetic basis by incorporating resistance alleles from wild and cultivated relatives is a promising approach for durum resistance breeding. This review summarizes the current information on sources available for FHB resistance improvement in durum wheat which include wild and cultivated tetraploid wheat, hexaploid wheat and alien species. The genetic basis of FHB resistance of a few tetraploid sources in the T. durum background has been dissected by QTL mapping. So far, thirteen QTL with small to moderate effects have repeatedly been detected on 11 chromosomes with alleles improving FHB resistance deriving from relatives and durum wheat itself. Notably, the QTL found in tetraploid wheat populations largely overlap with the QTL identified in hexaploid wheat suggesting a common genetic basis of FHB resistance. FHB resistance breeding by allele introgression into durum wheat is feasible, and QTL pyramiding appears a practicable strategy for durum resistance breeding. © 2014, Springer Science+Business Media Dordrecht.


PubMed | University of Natural Resources and Life Sciences, Vienna, University Blaise Pascal and Florimond Desprez
Type: Journal Article | Journal: TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik | Year: 2016

The QTL Fhb1 was successfully introgressed and validated in three durum wheat populations. The novel germplasm and the QTL detected will support improvement of Fusarium resistance in durum wheat. Durum wheat (Triticum durum Desf.) is particularly susceptible to Fusarium head blight (FHB) and breeding for resistance is hampered by limited genetic variation within this species. To date, resistant sources are mainly available in a few wild relative tetraploid wheat accessions. In this study, the effect of the well-known hexaploid wheat (Triticum aestivum L.) quantitative trait locus (QTL) Fhb1 was assessed for the first time in durum wheat. Three F7-RIL mapping populations of about 100 lines were developed from crosses between the durum wheat experimental line DBC-480, which carries an Fhb1 introgression from Sumai-3, and the European T. durum cultivars Karur, Durobonus and SZD1029K. The RILs were evaluated in field experiments for FHB resistance in three seasons using spray inoculation and genotyped with SSR as well as genotyping-by-sequencing markers. QTL associated with FHB resistance were identified on chromosome arms 2BL, 3BS, 4AL, 4BS, 5AL and 6AS at which the resistant parent DBC-480 contributed the positive alleles. The QTL on 3BS was detected in all three populations centered at the Fhb1 interval. The Rht-B1 locus governing plant height was found to have a strong effect in modulating FHB severity in all populations. The negative effect of the semi-dwarf allele Rht-B1b on FHB resistance was compensated by combining with Fhb1 and additional resistance QTL. The successful deployment of Fhb1 in T. durum was further substantiated by assessing type 2 resistance in one population. The efficient introgression of Fhb1 represents a significant step forward for enhancing FHB resistance in durum wheat.


PubMed | Florimond Desprez
Type: Journal Article | Journal: Plant cell reports | Year: 2013

A method to remove the exine from mature tobacco pollen and to release numerous intact pollen protoplasts has been developed. Post-anthesis binucleate pollen was treated with water, buffered with MES at pH 5.5, for two hours. Rupture of the exine was caused by the force of pollen hydration exposing the intine to subsequent enzymatic maceration. The high osmotic pressure (1000 mOsmkg(-1) H2O) of pollen protoplasts required a special maceration medium, 4% KCl (w/v). Action of an enzyme solution containing 1% (w/v) Macerozyme and 1% (w/v) Cellulase gave rise to viable protoplasts within 4 hours. When cultured in a tobacco mesophyll protoplast culture medium, the pollen protoplasts underwent regeneration of a cell wall, formation of various tube-shaped structures, and division of the generative nucleus into two nuclei. Using a PEG/Ca(2+) method pollen protoplasts were fused with diploid mesophyll protoplasts. Evidence of transfer of chloroplasts into the pollen protoplasts was observed after one day of culture.


PubMed | Florimond Desprez
Type: Journal Article | Journal: Plant cell reports | Year: 2013

Mature pollen protoplasts (n) isolated from kanamycin resistant plants of Nicotiana tabacum (2n = 4x = 48) were fused with somatic mesophyll protoplasts (2n) of Nicotiana plumbaginifolia (2n = 20) to produce plants. A total of 3.610(6) mature pollen protoplasts were fused with 710(6) mesophyll protoplasts using a PEG/Ca(2+) method. Mature pollen protoplasts did not divide in our culture conditions, and N. plumbaginifolia protoplasts stopped dividing when the protoplast-derived colonies were transferred to a selection medium containing paromomycine (20 mgl(-1)). A total of 133 actively growing colonies were recovered on the selection medium containing kanamycin (100 mgl(-1)). Plants from twenty resulting cell lines were confirmed as hybrids (17) or cybrids (3) based on leaf and floral morphology and fertility analysis. Isozyme pattern analysis confirmed the nuclear hybrid and cybrid nature, respectively, for 2 and 3 typical gametosomatic selected plants. Root tip squashes of 6 of the gametosomatic hybrid plants revealed chromosome numbers ranging from 44 to 68; the 3 selected cybrid plants had 48 chromosomes. Evidence for organelle transmission from the mesophyll partner in the gametosomatic plants is shown. From the analysis it can be concluded that the gametosomatic fusion involving mature pollen protoplasts (n) carrying a dominant selection marker can be convenient for synthesis of either hybrids or cybrids. Such gametosomatic fusion is therefore considered as a new approach towards the production of androgenetic plants with a choosen cytoplasm.

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