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Cappelle-en-Pévèle, France

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. Source

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. Source

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. Source

Loyce C.,Agro ParisTech | Meynard J.M.,French National Institute for Agricultural Research | Bouchard C.,French National Institute for Agricultural Research | Rolland B.,French National Institute for Agricultural Research | And 15 more authors.
Field Crops Research | Year: 2012

Since the 1970s, winter wheat management in France has focused on growing high-yielding cultivars with the intensive use of external inputs. However, over the last 10 years, breeding priorities have changed in favour of the development of cultivars with multiple resistance to fungal diseases and lodging. Low-input strategies have also been developed, to reduce costs and to meet environmental targets. In this study, we assessed the economic, energetic and environmental performances of three cultivars (C) grown under four management intensities. Two of these cultivars (Isengrain and Trémie) are both high-yielding and disease-susceptible, whereas the third (Oratorio) is multiresistant to diseases and lodging but has a lower potential yield. The four crop management systems (CM) were designed with a decrease in input level (seeds, N fertilizer, fungicides, growth regulator) from CM1 to CM4. We set up a multi-year and multi-site network to test the C-CM pairs in a wide range of environments. The evaluation of C-CM pairs was based on a set of indicators dealing with economics (profitability, input and machinery costs per tonne), environment (pesticide use, N recovery), and energy (energy use efficiency, energy costs). As regards profitability and costs per tonne, we assessed the vulnerability of the C-CM pairs to several grain and oil price scenarios. The demonstration of synergy between the two types of innovation (multiresistant cultivars, low-input management) is a major result: each makes the other more profitable, increasing its chances of adoption in the field. The ecology-based technology package, involving the use of lower-yielding multiresistant cultivars under lower external input levels, was more profitable when grain prices were low (less than €123-157 per tonne (for low and high oil prices, respectively)). By contrast, the intensive technology package, consisting of high-yielding cultivars and high levels of external inputs (N, fungicides and growth regulators), was more profitable when grain prices exceeded €123-157 per tonne (for low and high oil prices, respectively). However, it was less optimal in terms of fossil energy use and potential environmental impact. In a context of fluctuating grain and oil prices and a need to preserve resources (e.g. fossil energy, water quality), our results demonstrate the potential benefits of using low-input crop management systems, with cultivars displaying multiple resistance to diseases and lodging (Oratorio-CM3). The loss of productivity (1tha-1 less than for Isengrain-CM2) due to the lower yield potential of the multiresistant cultivar and the lower levels of inputs must be seen as a necessary evil if we are to decrease the overuse of resources. There is a need to adapt current procedures for cultivar evaluation, to promote the breeding of multiresistant cultivars for low-input systems. New cultivars should be evaluated under a range of conditions, from high- to low-input systems. © 2011 Elsevier B.V. Source

Loaec G.,Polytechnic Institute of LaSalle Beauvais | Niquet-Leridon C.,Polytechnic Institute of LaSalle Beauvais | Henry N.,Florimond Desprez | Jacolot P.,Polytechnic Institute of LaSalle Beauvais | And 8 more authors.
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, Nε-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). © 2015 American Chemical Society. Source

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