Canadian Forest Service Publications

Plant growth regulators for enhancing Alberta native grass and forb seed germination. 2019. Small, C.C.; Degenhardt, D.; McDonald, T. Ecological Engineering:X 1(2019):100003.

Year: 2019

Issued by: Northern Forestry Centre

Catalog ID: 39798

Language: English

CFS Availability: PDF (download)

Available from the Journal's Web site.
DOI: 10.1016/j.ecoena.2019.100003

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A germination trial was conducted to screen effects of plant growth regulators (PGRs) on 9 Alberta native grass and forb species with the aim of identifying PGRs with the capacity to improve seed germination and early plant development in disturbed and reconstructed soil conditions. Seeds were treated with 500 mg/L of various gibberellins (GA3 40 [40% GA3], GA3 90 [90% GA3], and GA4/7), 5 mg/L cytokinin (kinetin), and 0.1 mg/L brassinosteroids (brassinolide). Experiments were conducted in a growth chamber following a 24 h soaking period. PGR seed treatment did not significantly increase percent (%) germination for the majority of species, but rather assisted in breaking seed dormancy and enhancing early radical emergence. Early germination at day 7 was measured for Fragaria virginiana (130–150% increase over the control for GA3 40, GA3 90, GA4/7, and brassinolide), Koeleria macrantha (36% increase for GA3 40), Poa palustris (98–123% increase for all PGRs), Agrostis scabra (42–56% increase for all PGRs) and Festuca hallii (85–93% increase for kinetin and brassinolide). Gibberellin treatments were significantly more effective in improving shoot growth; kinetin and brassinolide were significantly more effective in enhancing root development for the majority of tested plant species. PGRs having the greatest overall impact on seed germination and plant development, as measured by vigor index were brassinolide and GA4/7. Tested PGRs have the potential to benefit native grass and forb restoration and re-vegetation efforts, improving the efficacy of planting prescriptions, with the aim of increasing early groundcover, stabilizing soils, enhancing biodiversity, and reducing the time to reclamation certification.

Plain Language Summary

When land is reclaimed after industrial activity such as mining, one of the major challenges is to get native plants re-established on the site. We conducted a germination study to screen the effects of plant growth regulators on nine species of grasses and forbs (non-woody plants that are not grasses) that are native to Alberta. We hoped to identify those plant growth regulators with the potential to improve seed germination and early plant development. We anticipated that this could provide native plants with a competitive advantage over aggressive nonnative species. We found that products containing brassinolide enhanced root length, while products containing gibberellin A increased shoot growth after 14 days. These same products had the greatest positive effect on the vigor with which all nine of the native plant species grew. Native grasses become established on sites more slowly than weeds and agronomic species; therefore, an increase in seedling vigor should help native species to survive, especially under less than ideal environmental conditions. Our results indicate that the application of plant growth regulators to native plant species might help to reduce the time required to establish self-sustaining native plant communities on reclaimed lands.

#39798 / 18-12-J L’un des grands défis liés à la remise en état des terres après des activités industrielles, comme des activités d’extraction minière, consiste à faire pousser des plantes indigènes sur le site. Nous avons réalisé une étude sur la germination pour déterminer les effets de régulateurs de croissance des plantes sur neuf espèces de graminées et de plantes herbacées (plantes non ligneuses qui ne sont pas des graminées) qui poussent en Alberta. Nous espérions identifier les régulateurs de croissance ayant le potentiel d’améliorer la germination des graines et le développement précoce des plantes. Nous pensions que cela pourrait fournir un avantage concurrentiel aux plantes indigènes par rapport aux espèces étrangères agressives. Nous avons découvert que les produits contenant de la brassinolide augmentaient la longueur des racines, tandis que les produits contenant de la gibbérelline A amélioraient la croissance des pousses après 14 jours. Ces produits avaient les effets les plus positifs sur la vigueur de neuf espèces de plantes indigènes. Les graminées indigènes présentes sur le site poussaient plus lentement que les mauvaises herbes et les espèces agronomiques. L’augmentation de la vigueur des semis devrait donc aider les espèces indigènes à survivre, surtout dans des conditions environnementales qui sont loin d’être idéales. Nos résultats indiquent que l’utilisation de régulateurs de croissance avec des espèces indigènes pourrait aider à réduire le temps requis pour faire pousser des plantes indigènes autonomes sur des terres remises en état.