1.5 Flashcards
Advantages of seed banks
Ease if storage.
Economy if space.
Relatively low labour costs.
Capacity to store large samples at economically viable cost.
Why store plant seeds not complete plant?
Seeds are a convenient means of long-term storage of genetic diversity.
Samples are small in size, easily handled, require low maintenance and frequently remain viable for long periods.
In general seeds require low temperatures and dedication to allow seeds to maintain viability.
Economical with space.
Disadvantages of seed banks
Can be expensive to run because of the need to maintain low temperatures.
Germination tests, growth trials and regeneration can be expensive.
Not suitable for plants with recalcitrant seeds
How are botanic gardens involved in seed banks?
Worldwide botanic gardens store seeds in seed banks.
Mainly wild species stored.
Isolate embryos, minute seeds and tissues can be stored in conditions of cryopreservation.
These techniques have potential to preserve and maintain biodiversity.
Examples of seed banks
Kew’s Millennium Seed Bank at Wakehurst Place.
Rôle of Seed Banks in Conserving UK Native Species
Preserve genetic diversity, seed bank is kind of genre bank.
Preserves genes that plant breeders need to:
Improve yield.
Increase disease resistance.
Improve drought tolerance.
Improve nutritional quality and taste.
Also forestalls loss of genetic diversity in rare and imperiled species.
Better than ‘living’ collections that can be damaged by natural and man made incidents, war, disease etc.
Seed provenance
Definition
Refers to the specified area in which plants that produced seed are located or were derived. ie. place of origin.
Also refers to the origin or original home of a particular population or strain.
Provenance means that, in essence, separate races have developed in different regions which vary greatly in frost hardiness, rates of growth, ultimate height, moisture stress resistance and susceptibility to pests and diseases.
Importance of provenance.
It is vital that particular habitats are noted eg. altitude, exposure to weather and soil type.
Seed with appropriate provenance is used for reintroduction into a habitat/geographic region.
Hedgerow Planting
Planting in rows - often staggered to set spacing dependent on species.
Generally 70% Crataegus monogyna and 30% of one of the following Acer campestre, Prunus spinosa, Corylus avellana, Rosa canina, Ilex aquifolium, Euonymus europaeus, Viburnum opulus, Cornus sanguinea,.
Hedgerow planting provides?
Boundaries to divide fields and define ownership.
Shelter for farm animals.
Screening of buildings for security and visual appeal.
Habitat for wildlife and insects.
Conservation corridors linking small woodlands.
Hedgerow Planting Production
Example
Acer campestre
Generally produces satisfactory seed crops every year.
Acer campestre
Collection of seeds.
Collect winged seeds (samaras) in Sept/Oct, when they are light brown/yellow in colour.
Collect before they produce a hard seed coat and growth inhibitors.
Acer campestre
When to sow seed
Sow immediately after gathering seed (Sept/Oct)
Or
Store by mixing with appropriate medium and stored in warmth for 4-8wks and then chilled for 12-24wks
Should germinate in late winter.
Acer campestre
Seedbed
Trees need tilths which allow seeds to obtain adequate water and nutrients.
Beds 1m wide.
Alleys 0.5m in between.
Raised 20cm in wet areas and 4cm on east coast.
Acer campestre
Seedbed preparation
Weed bed- using appropriate herbicide or organic method. Subsoiling -1.8m centres, 450mm depth. Plough transverse to subsoil direction. Mark out bed. If necessary apply base dressing. Roll to consolidate. Ready for drilling.
