Rincent R.,French National Institute for Agricultural Research |
Rincent R.,KWS Saat AG |
Nicolas S.,French National Institute for Agricultural Research |
Bouchet S.,French National Institute for Agricultural Research |
And 23 more authors.
Theoretical and Applied Genetics | Year: 2014
Key message: Genetic and phenotypic analysis of two complementary maize panels revealed an important variation for biomass yield. Flowering and biomass QTL were discovered by association mapping in both panels.Abstract: The high whole plant biomass productivity of maize makes it a potential source of energy in animal feeding and biofuel production. The variability and the genetic determinism of traits related to biomass are poorly known. We analyzed two highly diverse panels of Dent and Flint lines representing complementary heterotic groups for Northern Europe. They were genotyped with the 50 k SNP-array and phenotyped as hybrids (crossed to a tester of the complementary pool) in a western European field trial network for traits related to flowering time, plant height, and biomass. The molecular information revealed to be a powerful tool for discovering different levels of structure and relatedness in both panels. This study revealed important variation and potential genetic progress for biomass production, even at constant precocity. Association mapping was run by combining genotypes and phenotypes in a mixed model with a random polygenic effect. This permitted the detection of significant associations, confirming height and flowering time quantitative trait loci (QTL) found in literature. Biomass yield QTL were detected in both panels but were unstable across the environments. Alternative kinship estimator only based on markers unlinked to the tested SNP increased the number of significant associations by around 40 % with a satisfying control of the false positive rate. This study gave insights into the variability and the genetic architectures of biomass-related traits in Flint and Dent lines and suggests important potential of these two pools for breeding high biomass yielding hybrid varieties. © 2014, Springer-Verlag Berlin Heidelberg.
Rincent R.,University Paris - Sud |
Rincent R.,KWS Saat AG |
Laloe D.,French National Institute for Agricultural Research |
Nicolas S.,University Paris - Sud |
And 17 more authors.
Genetics | Year: 2012
Genomic selection refers to the use of genotypic information for predicting breeding values of selection candidates. A prediction formula is calibrated with the genotypes and phenotypes of reference individuals constituting the calibration set. The size and the composition of this set are essential parameters affecting the prediction reliabilities. The objective of this study was to maximize reliabilities by optimizing the calibration set. Different criteria based on the diversity or on the prediction error variance (PEV) derived from the realized additive relationship matrix-best linear unbiased predictions model (RA-BLUP) were used to select the reference individuals. For the latter, we considered the mean of the PEV of the contrasts between each selection candidate and the mean of the population (PEVmean) and the mean of the expected reliabilities of the same contrasts (CDmean). These criteria were tested with phenotypic data collected on two diversity panels of maize (Zea mays L.) genotyped with a 50k SNPs array. In the two panels, samples chosen based on CDmean gave higher reliabilities than random samples for various calibration set sizes. CDmean also appeared superior to PEVmean, which can be explained by the fact that it takes into account the reduction of variance due to the relatedness between individuals. Selected samples were close to optimality for a wide range of trait heritabilities, which suggests that the strategy presented here can efficiently sample subsets in panels of inbred lines. A script to optimize reference samples based on CDmean is available on request. © 2012 by the Genetics Society of America.
Zaharieva M.,University of Lima |
Bonjean A.,Limagrain |
Monneveux P.,International Potato Center
Genetic Resources and Crop Evolution | Year: 2014
Wheat landraces cultivated in the Saharan oases have been submitted during centuries to drought, heat and salinity and are expected to have developed tolerance to these constraints. The different forms present in the oases of Libya, Algeria and Morocco have been collected and described by several authors who highlighted the peculiarity and diversity of this germplasm, on the basis of spike and grain morphology. The origin, date and way of introduction of wheat in the Saharan oases are however largely unknown. Most landraces may have been introduced from Egypt, possibly during wet climatic episodes. Spike morphological traits of some landraces suggest an Asiatic origin (Iran, Turkestan and Afghanistan). More recent introductions have also probably occurred. This lack of information as well as the potential interest of this germplasm for wheat improvement would merit further studies. Marker-based diversity analysis of Saharan wheats and comparison with North-African and Asian wheats might permit to precise their classification and confirm their origin. Evaluation for tolerance to abiotic constraints would allow a better understanding of their adaptation to the oases environments and identification of potential progenitors to be used by wheat breeders. Such studies are urgent considering the quick genetic erosion of this germplasm due to drastic ecological and socio-economic changes affecting Saharan oases and their cropping systems. © 2014 Springer Science+Business Media Dordrecht.
Allen A.M.,University of Bristol |
Barker G.L.A.,University of Bristol |
Wilkinson P.,University of Bristol |
Burridge A.,University of Bristol |
And 12 more authors.
Plant Biotechnology Journal | Year: 2013
Globally, wheat is the most widely grown crop and one of the three most important crops for human and livestock feed. However, the complex nature of the wheat genome has, until recently, resulted in a lack of single nucleotide polymorphism (SNP)-based molecular markers of practical use to wheat breeders. Recently, large numbers of SNP-based wheat markers have been made available via the use of next-generation sequencing combined with a variety of genotyping platforms. However, many of these markers and platforms have difficulty distinguishing between heterozygote and homozygote individuals and are therefore of limited use to wheat breeders carrying out commercial-scale breeding programmes. To identify exome-based co-dominant SNP-based assays, which are capable of distinguishing between heterozygotes and homozygotes, we have used targeted re-sequencing of the wheat exome to generate large amounts of genomic sequences from eight varieties. Using a bioinformatics approach, these sequences have been used to identify 95 266 putative single nucleotide polymorphisms, of which 10 251 were classified as being putatively co-dominant. Validation of a subset of these putative co-dominant markers confirmed that 96% were true polymorphisms and 65% were co-dominant SNP assays. The new co-dominant markers described here are capable of genotypic classification of a segregating locus in polyploid wheat and can be used on a variety of genotyping platforms; as such, they represent a powerful tool for wheat breeders. These markers and related information have been made publically available on an interactive web-based database to facilitate their use on genotyping programmes worldwide. © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.
Ober E.S.,UK National Institute of Agricultural Botany |
Werner P.,KWS UK |
Flatman E.,Limagrain |
Angus W.J.,Angus Wheat Consultants Ltd |
And 3 more authors.
Functional Plant Biology | Year: 2014
The ability of roots to extract soil moisture is critical for maintaining yields during drought. However, the extent of genotypic variation for rooting depth and drought tolerance in Northern European wheat (Triticum aestivum L.) germplasm is not known. The objectives of this study were to measure genotypic differences in root activity, test relationships between water use and yield, examine trade-offs between yield potential and investment of biomass in deep roots, and identify genotypes that contrast in deep root activity. A diverse set of 21 wheat genotypes was evaluated under irrigated and managed drought conditions in the field. Root activity was inferred from patterns of water extraction from the soil profile. Genotypes were equally capable of exploiting soil moisture in the upper layers, but there were significant genotypic differences in rates of water uptake after anthesis in deeper soil layers. For example, across the three years of the study, the variety Xi19 showed consistently deeper root activity than the variety Spark; Xi19 also showed greater drought tolerance than Spark. There were positive correlations between water extraction from depth and droughted yields and drought tolerance, but correlations between deep water use and yield potential were not significant or only weakly negative. With appropriate screening tools, selection for genotypes that can better mine deep soil water should improve yield stability in variable rainfall environments. © CSIRO 2014.
Dumitru L.M.,Research Station for Fruit Growing |
Gavat C.,Research Station for Fruit Growing |
Dumitru D.V.,Limagrain |
Stanica F.,University of Bucharest
Acta Horticulturae | Year: 2015
Nectarine tree is one of the most appreciated fruit species cultivated in the temperate climate for special qualities of fruit and for the particularities of the trees (precocious, productive and proper capacity to recover after climatic damages). In the last years, in Romania, the orchard owners' aims were to plant intensive orchards and to use dwarf and semi-dwarf trees. In this paper we present some nectarine and brugnone cultivars, which produced good results in the south-eastern part of Romania. The recommended nectarine cultivars are: 'Melania', 'Nəicə', and 'Liviu', that are dwarf cultivars, and 'Valerica', a semi-dwarf brugnone. © 2015 ISHS.
McVetty P.B.E.,University of Manitoba |
Biocatalysis and Agricultural Biotechnology | Year: 2012
This review describes the discovery of a prokaryotic gene conferring tolerance to the broad spectrum, broadleaf herbicide bromoxynil, the development of chimeric genes suited to eukaryotic organisms, the transformation of broadleaf plants with several versions of the bromoxynil tolerance chimeric genes and the selection of the best constructs and inserts (events) in Brassica napus. This review further describes the use of the pRPA-BL-235 bromoxynil tolerance construct in canola cultivar development and commercial bromoxynil tolerant canola (Navigator Compas™) production in Canada. Regulatory aspects involved in the development and commercialization of a new chimeric gene crop in Canada are reviewed. Finally, the steps taken to remove bromoxynil tolerant canola from breeding programs, commercial production, the environment and the market are reviewed. © 2012.