Why are the seeds of this species difficult? Some sub-species may have seeds with physiological dormancy. Wild-growing sub-species may produce a high proportion of empty seeds, which collectors and curators must take account of.
Triticum aestivum (Image: S. Wood, RBG Kew)
This species has Orthodox seeds - dry to 15-20% eRH and store at -20ºC, or as cool as possible.
Germinate on agar, germination paper (top of paper or between paper) or sand at 15 or 20°C. 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.
Some sub-species may have seeds with non-deep Physiological Dormancy, particularly if grown in cool locations. If germination is low, use a moist pre-chill or pre-heat (30-35°C) treatment (depending on local climatic conditions) to overcome dormancy.
The occurrence of empty seeds is common in wild-collected accessions of this species. Empty seeds may have a normal seed coat but an absent or under-developed embryo, or limited storage tissue.
The seeds are oval in shape, with usually two per spikelet, and have a central groove on the ventral surface and a terminal tuft of hairs. The endosperm is starchy and glutinous, surrounding the basal dorsal embryo.
Triticum aestivum section
(Image: S. Wood, RBG Kew)
Accepted name: Triticum aestivum L.
Synonyms: Triticum vulgare Vill. var. aestivum (L.) Fisch., Triticum aestivum L. subsp. vulgare (Vill.) Domin, Triticum sativum Lam. subsp. vulgare (Vill.) Voss, Triticum sativum Lam., Triticum sativum Lam. var. vulgare (Vill.) Desv.
Common name: common wheat
References and Links
- Baskin, C.C. and Baskin J.M. (1998). Seeds: ecology, biogeography, and evolution of dormancy and germination. Academic Press, USA.
- 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.
- International Seed Testing Association (2010). International Rules for Seed Testing: edition 2010. ISTA, Bassersdorf, Switzerland.
- Purseglove, J.W. (1972). Tropical Crops: monocotyledons. Longman Group Ltd., UK.
- Priestley, D.A. (1986). Seed Ageing. Cornell University Press, USA.
- Rao, N.K., Hanson, J., Dulloo, M.E., Ghosh, K., Nowell, D. and Larinde, M. (2006). Manual of seed handling in genebanks. Handbooks for Genebanks No. 8. Bioversity International, 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: Triticum aestivum.
- PROTAbase (Plant Resources of Tropical Africa) - Wageningen, Netherlands: Triticum aestivum.
- SID (Seed Information Database) - Royal Botanic Gardens, Kew, UK: Triticum aestivum.
- Tropicos - Missouri Botanical Garden, USA: Triticum aestivum.