Impact of breeding selection and agronomy on cereal roots
Notice bibliographique
Résumé
Cereals are an important part of the prairie cropping system. Their production in the Canadian Prairies is hindered by several biotic and abiotic stresses and production challenges. To mitigate crop production challenges and improve yield, breeders have developed cultivars that are adapted to diverse environmental conditions by employing different management practices, such as the application of Plant Growth Regulators (PGRs). However, efforts to mitigate crop production challenges have focused on shoot traits (i.e., aboveground parameters), while studies on root traits are largely unexplored. Roots are crucial for anchorage, water, and nutrient uptake, and play a vital role in regulating plant metabolic and physiological functions. Addressing agronomic challenges from a root’s perspective is important to make crops more resilient to ever-growing problems compounded by climate change. Therefore, two experiments were conducted at the Plant Growth Facility, University of Alberta (UofA), and the Growth Chamber, Biological Science Building, UofA, respectively, to explore (i) the impact of breeding selection over time on root traits and (ii) the effects of PGR application on root traits of barley sown at different seeding rates. In the first experiment, we assessed the impact of breeding selection on the root traits of old versus current barley cultivars and winter wheat genotypes. The experiment was a Randomized Complete Block Design with four replications, repeated twice (blocks), with six barley cultivars (three old and three current cultivars) and four winter wheat genotypes (two old and two current). The old barley cultivar, Bonanza, had significantly higher total root length (TRL) compared to the current popular barley cultivar, AAC Synergy, with which it shares a similar pedigree. All other current barley cultivars (AB Standswell, AB Advantage, and AAC Synergy) sharing a similar pedigree with Bonanza had a significantly lower proportion of their TRL in the small root diameter \n class compared to Bonanza. Current winter wheat genotypes assessed had similar root traits and similar root diameter class distribution, with old winter wheat genotypes sharing a similar pedigree. Therefore, breeding selection conducted in the Canadian Prairies over the last 40 years, together with changes in tillage practices to conservation tillage, decreased TRL in the popular current barley variety, AAC Synergy, and enhanced root fineness in all current barley cultivars. No impact was observed in winter wheat. In the second experiment, we evaluated the effects of PGRs and seeding rates on popular Canadian feed and malting barley cultivars, along with one best-performing old cultivar (Kasota) selected from the first experiment. The study was a split-split-plot experiment with PGR treatments (PGR versus No-PGR/control), three barley seeding rates (1-plant/pot, 2-plants/pot, and 4 plants/pot), and three barley cultivars (AB Cattlelac - feed, Kasota - old, and AAC Synergy- malting barley cultivars) replicated four times; the study was repeated twice (blocks). Moddus (commercial PGR registered in Canada for barley) was sprayed at BBCH 31-32. Plant height, shoot dry weight, and total biomass significantly reduced at all seeding rates with PGR application, while tiller numbers significantly increased when one plant was sown per pot with PGR application. Total root length, total root surface area, root dry weight, root volume, and root shoot ratio significantly increased at all seeding rates with PGR application, while mean root diameter significantly reduced. Specific root length increased significantly with PGR application when one plant was sown per pot, while the other seeding rate showed no significant differences. Higher seeding rate significantly reduced shoots and root parameters in all assessed barley cultivars. There was a significant interaction of PGRs x seeding rates for tiller numbers and specific root length traits. Therefore, as the key finding is that PGR application and seeding rate singly or in combination significantly impacted barley root traits.
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
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Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| 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 ».