Why are the seeds of this species difficult? The seeds may have physiological dormancy, which would have to be overcome before they will germinate. The seeds are also relatively short-lived, so may not remain viable for a long time in storage.
Brassica oleracea (Image: S. Wood, RBG Kew)
This species has Orthodox seeds - dry to 15-20% eRH and store at -20ºC, or as cool as possible.
The seeds of this species are relatively Short-lived in storage. Monitor viability at least every five years, and more frequently once viability begins to decline. When viability falls close to the regeneration standard, the collection will need to be re-generated or re-collected.
Remove seed covering structures before sowing. Germinate on agar, germination paper or sand, under a constant temperature of 16 or 21°C. An alternating temperature regime of 23/9ºC (with a 12hrs light and 12 hrs darkness) can also be used.
The seeds of this species may have Physiological Dormancy (based on other species in the same genus).If germination is low, this type of seed dormancy can be overcome by mimicking the seasonal patterns of the species' native habitat. Use a moist pre-chill or pre-heat treatment (depending on local climatic conditions) or a dry after-ripening treatment, before germinating the seeds on agar, germination paper or sand at their optimum temperature. If this does not work, you can perform delicate surgery to enable the embryo to grow. Excise the tissue near the root tip.
(Image: S. Wood, RBG Kew)
Accepted name: Brassica oleracea L.
Synonyms: Brassica oleracea var. glauca A.Chev.
Common name: various
References and Links
- Food and Agriculture Organization of the United Nations and International Plant Genetic Resources Institute (1994). Genebank Standards. FAO/IPGRI, Rome, Italy.
- Walters, C., Wheeler, L.M., Grotenhuis, J.M. (2005). Longevity of seeds stored in a genebank: species characteristics. Seed Science Research, 15 (1): 1-20.
- AFPD (African Flowering Plants Database) - Conservatoire et Jardin Botaniques de la Ville de Genève, Switzerland, and South African National Biodiversity Institute, Pretoria, RSA: Brassica oleracea.
- AVRDC - The World Vegetable Centre, Taiwan: fact sheet on Brassica oleracea.
- PROTAbase (Plant Resources of Tropical Africa) - Wageningen, Netherlands: Brassica oleracea.
- SID (Seed Information Database) - Royal Botanic Gardens, Kew, UK: Brassica oleracea.
- Tropicos - Missouri Botanical Garden, USA: Brassica oleracea.