71 research outputs found
Improving the quality of African robustas: QTLs for yield- and quality-related traits in Coffea canephora.
Author Correction: A chickpea genetic variation map based on the sequencing of 3,366 genomes
In Extended Data Fig. 1 of this Article, the labels ‘Market class’ and ‘Biological status’ were inadvertently swapped. In the corresponding figure legend, “Track 1: Biological status; Track 2: Market class;” should have been “Track 1: Market class; Track 2: Biological status;”. The original Article has been corrected online
Foundation characteristics of edible Musa triploids revealed from allelic distribution of SSR markers
Background and Aims The production of triploid banana and plantain (Musa spp.) cultivars with improved characteristics (e.g. greater disease resistance or higher yield), while still preserving the main features of current popular cultivars (e.g. taste and cooking quality), remains a major challenge for Musa breeders. In this regard, breeders require a sound knowledge of the lineage of the current sterile triploid cultivars, to select diploid parents that are able to transmit desirable traits, together with a breeding strategy ensuring final triploidization and sterility. Highly polymorphic single sequence repeats (SSRs) are valuable markers for investigating phylogenetic relationships. Methods Here, the allelic distribution of each of 22 SSR loci across 561 Musa accessions is analysed. Key Results and ConclusionsWe determine the closest diploid progenitors of the triploid 'Cavendish' and 'Gros Michel' subgroups, valuable information for breeding programmes. Nevertheless, in establishing the likely monoclonal origin of the main edible triploid banana subgroups (i.e. 'Cavendish', 'Plantain' and 'Mutika- Lujugira'), we postulated that the huge phenotypic diversity observed within these subgroups did not result from gamete recombination, but rather from epigenetic regulations. This emphasizes the need to investigate the regulatory mechanisms of genome expression on a unique model in the plant kingdom. We also propose experimental standards to compare additional and independent genotyping data for reference. (Résumé d'auteur
A western Sahara centre of domestication inferred from pearl millet genomes
There have been intense debates over the geographic origin of African crops and agriculture. Here, we used whole-genome sequencing data to infer the domestication origin of pearl millet (Cenchrus americanus). Our results supported an origin in western Sahara, and we dated the onset of cultivated pearl millet expansion in Africa to 4,900 years ago. We provided evidence that wild-to-crop gene flow increased cultivated genetic diversity leading to diversity hotspots in western and eastern Sahel and adaptive introgression of 15 genomic regions. Our study reconciled genetic and archaeological data for one of the oldest African crops
Resequencing of 429 chickpea accessions from 45 countries provides insights into genome diversity, domestication and agronomic traits
We report a map of 4.97 million single-nucleotide polymorphisms of the chickpea from whole-genome resequencing of 429 lines sampled from 45 countries. We identified 122 candidate regions with 204 genes under selection during chickpea breeding. Our data suggest the Eastern Mediterranean as the primary center of origin and migration route of chickpea from the Mediterranean/Fertile Crescent to Central Asia, and probably in parallel from Central Asia to East Africa (Ethiopia) and South Asia (India). Genome-wide association studies identified 262 markers and several candidate genes for 13 traits. Our study establishes a foundation for large-scale characterization of germplasm and population genomics, and a resource for trait dissection, accelerating genetic gains in future chickpea breeding
Assessing microsatellite linkage disequilibrium in wild, cultivated, and mapping populations of Theobroma cacao L. and its impact on association mapping
Nucleotide diversity of genes involved in sucrose metabolism. Towards the identification of candidates genes controlling sucrosse variability in Coffea sp.
Quality and drought stress tolerance are two important targets for Coffea species cultivation. Currently, efficient genetic improvement of these traits is still hampered by the lack of early and cheap predictors. In this context, identification of molecular tools linked to these traits would significantly improve breeding efficiency. Based on the available literature, different metabolisms involved in the variability of both drought tolerance and coffee quality can be proposed. Based on this information, a study was initiated in Coffea species, aiming at estimating nucleotide diversity of four sucrose metabolism enzymes (Sucrose Synthase, Cell Wall Invertase, acid Vacuolar Invertase and Sucrose Phosphate Synthase). The two mains objectives of this work were i) to assess the level of variability of these genes within the whole area of distribution of Coffea canephora, and within 15 related Coffea species representing the four groups of diversity of this genus, and ii) to identify polymorphisms useful for mapping and association genetic studies. Almost 200 polymorphisms (SNP, INDELS, SSR) were identified through sequencing of Coffea canephora genotypes. In addition, analysis of the variability of these genes between different Coffea species allowed the identification of 300 additional polymorphic sites. Parallel in-silico analysis of EST resources confirmed the interest of this approach towards the identification of polymorphisms in Coffea sp. Identification of nucleotide polymorphisms will not only provide useful markers for traditional genetic studies (genetic mapping, population genetics, association studie) but also provide criteria to infer the evolutionary history of the analysed genes. Such information will be particularly relevant to select the best candidate genes to test in future association studies
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