Genomics of Drought Tolerance in Flax (Linum usitatissimum L.)
Notice bibliographique
Résumé
Flax (Linum usitatissimum L.), one of the eight founder crops of agriculture, is a versatile plant that has been a source of fiber and oil for millennia. Flax production, however, is constrained by various factors, including moisture stress. Yet, variations in the level of tolerance to different moisture regimes exists among flax germlines, thereby providing opportunities for breeders. To understand the global scale eco-geographic adaptation and to further gain insight into the genetic architecture of drought-related traits leading towards marker-assisted breeding and/or genomic selection in flax, a genome-wide investigation using high density single nucleotide polymorphism (SNP) data was performed in two sets of flax genotypes: a core (n=407) and a mini-core (n=115) collection, both representing the major world flax growing regions. The core collection was used to demonstrate haplotype distribution and possible driving forces that have shaped the population structure of the crop. The mini-core was used to perform genotype-phenotype association for drought-related traits through genome-wide association studies (GWAS) based on phenotypic values generated in two experiments. In the first experiment, 16 early root and shoot traits were evaluated using a semi-hydroponic pouch system in a controlled environment, while in the second experiment 11 drought-related traits were evaluated under irrigated and non-irrigated conditions. For the latter, GWAS was performed using the adjusted values of six of the measured traits that significantly responded to the watering regime, as well as six calculated stress indices for each trait. The genetic structure analysis clustered the core collection into four major groups: Temperate, South Asian, Mediterranean and Abyssinian. The Temperate group comprised the majority of the core collection and was dominated by accessions from Eurasia, the Americas and Oceania. Despite their limited representation, the other three groups harbored a high concentration of endemic haplotypes that can be attributed to the long history of flax cultivation in these regions hypothesized to be the centers of diversification the crop. More in-depth samplings from these regions is thus expected to broaden the genetic diversity of the flax core collection substantially. Genetic variation within morphotypes is more pronounced than between the fiber and oil types, reflecting selection of genotypes for dually elite traits i.e. both for seed and fiber. The overall result suggests the contribution of use-directed human selection and eco-geographic variations along the latitudinal gradient as major forces in shaping the genetic structure of the crop. The two GWAS experiments, i.e., early root-shoot growth and field-drought-tolerance-related traits, yielded 228 and 144 quantitative trait nucleotides (QTNs), respectively, that were associated with at least one trait. Most loci, 100 kb up- and downstream of the associated QTN, harbored genes predicted to play roles in modulating the associated trait or traits. In the root-shoot GWAS, genes predicted to encode GRAS transcription factors, mitogen-activated protein kinases (MAPKs), and auxin related lateral organ boundary proteins were present at root trait QTN loci, while QTN loci associated with shoot traits mainly harbored genes involved in photo-morphogenesis and plant immunity. QTN loci of drought tolerant traits consistently harbored genes known to mediate responses to abiotic stress, including drought, heat and salt, suggesting the importance of these loci for stress tolerance to be considered as candidate QTL of the traits associated with.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».