Why are the seeds of this species difficult? Species of the Anacardiaceae family can produce a high proportion of empty seeds, which collectors and curators must take account of. The seeds may have physiological dormancy, which can be overcome by mimicking the seasonal patterns of the species' native habitat.
Ozoroa obovata (Image: S. Wood, RBG Kew)
This species most probably has Orthodox seeds (based other species in the same genus) - dry to 15-20% eRH and store at -20ºC, or as cool as possible.
Based on the germination requirements for other species in the same genus: soak the seeds in water for 1 day (at 20 or 25ºC) to remove the fruit pulp, then chip the seeds with a scalpel before germinating on agar or sand at 20 or 25ºC. Perform a cut-test on any seeds that have not germinated, to check for empty seeds. All empty seeds are non-viable in germination tests.
The seeds of this species may be Physiologically Dormant (based on members of the same family). If germination is low, overcome dormancy 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)
The production of empty seeds is common in some species of the Anacardiaceae. Empty seeds may have a normal seed coat but an absent or under-developed embryo, or limited storage tissue.
Accepted name: Ozoroa obovata (Oliv.) R.Fern & A.Fern
References and Links
- Black, M., Bewley, J.D. and Halmer, P. (2006). The Encyclopaedia of Seeds: science, technology and uses. CAB International, UK.
- Food and Agriculture Organization of the United Nations and International Plant Genetic Resources Institute (1994). Genebank Standards. FAO/IPGRI, Rome, Italy.
- AFPD (African Flowering Plants Database) - Conservatoire et Jardin Botaniques de la Ville de Genève, Switzerland, and South African National Biodiversity Institute, Pretoria, RSA: Ozoroa obovata.
- PROTAbase (Plant Resources of Tropical Africa) - Wageningen, Netherlands: Ozoroa obovata.
- SID (Seed Information Database) - Royal Botanic Gardens, Kew, UK: Ozoroa obovata.
- Tropicos - Missouri Botanical Garden, USA: Ozoroa obovata.