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PAGE 63. ABBOTTS . The ovary (with ovules) grows and develops into fruit The stigma and style dry and fall off. The fruit protects the seed. SEED DISTRIBUTION. EXTRA STUFF. Fruit fall down, burst open and seeds are released. Seeds are distributed by: Wind Insects/other animals Water
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PAGE 63 ABBOTTS
The ovary (with ovules) grows and develops into fruit • The stigma and style dry and fall off. • The fruit protects the seed.
SEED DISTRIBUTION EXTRA STUFF • Fruit fall down, burst open and seeds are released. • Seeds are distributed by: • Wind • Insects/other animals • Water • Humans • Seeds are adapted according to the method in which they are dispersed, e.g. wings and hooks.
PAGE 63 • Many plant species are currently under threat • By saving seeds, many of these plants could be saved • A seed bank is a facility used to store seeds of various plants in an effort to maintain biodiversity • Many countries have seed banks
Kew millenium seed bank at Wakehurst Place, Sussex. Seed collections arrive by courier from around the world PAGE 63
The largest seed in the collection is the coco de mer seed and the smallest is a Chilean orchid – there are about 1m seeds in the vial
The seeds, together with pressed plant specimens and vital field data, are brought back to seed banks around the world for processing, research and long-term storage
Cleaning acer seeds. Once at the seed bank, seed is cleaned to reduce bulk and the risk of disease. This requires great care and expertise and to limit damage, much of the work is done by hand using sieves
Seeds in temperature cabinet, testing for viability. Most species have seeds that stay viable when dried to the low moisture levels necessary for long-term storage. However, certain species have seeds that are not tolerant to drying and cannot be conserved long-term in a seed bank. There are other ways to deal with these species
Once the seed has been dried to the required level it is packaged and placed in the cold room where it is kept at a temperature of -20C
The length of time that each collection can be stored for is fixed by the biology of the seed. Depending on the species, seeds may live centuries – and even millennia
Eucalyptus virginii seed. The next phase of the seed bank project is an even more ambitious target of collecting a total of 25% - about 75,000 - of the world's plant species by 2020
The Svalbard Global Seed Vault • which is established in the permafrost in the mountains of Svalbard, is designed to store duplicates of seeds from seed • collections around the globe. Many of these collections are in developing • countries. PAGE 63 Built into a reinforced concrete tunnel Drilled 70m into the mountain Aims to store 4.5 million seed samples from Every country in the world Store seeds at -180C Will be viable for thousands of years
PAGE 63 • Seeds can be grown to replace seeds that are lost as a result of • Over-exploitation of wild plants • Invasion of alien plant species • Habitat loss (development of cities etc) • Seeds can be grown to maintain/restore biodiversity • Seeds can be used for research in bio-engineering (try and find solutions to crop failures) • Seeds can be grown to produce plants for pharmaceutical research
Seeds contain stored food (starch, protein, oil) for feeding the new plant until it can support itself • Seeds are a good source of food for humans • Roots, stems, leaves, flowers and fruits are also food sources for humans! PAGE 64
IMPORTANCE OF GRAINS AND PULSES PAGE 64
PAGE 64 • eg maize, wheat, rice, oats provide: • A rich source of starch which is a good source of energy • Fibre from the seed coat of whole grains helps to keep the • bowel healthy • Most of the B vitamins and many minerals from the seed coat • Small amounts of protein and fat
PAGE 65 • Eg lentils, peas, beans, peanuts and soya beans • Are a good source of protein, minerals and B Vitamins • Help regulate blood sugar levels
PAGE 65 • Eg almonds, pecans, cashews • Are a good source of energy • Are rich in monounsaturated or polyunsturated fatty • acids (healthier than animal fat) • Supply Vitamin E
PAGE 65 • Eg peanuts, soybeans, corn, sunflower and canola • Are rich in monounsaturated or polyunsaturated fatty acids • Can contain vital omega-3 fatty acids
PAGE 66 • An endemic plant is one that grows only in one specific geographic area or habitat type • Of the 20 000 plant species in South Africa, 66% are endemic to various parts of the country • Endemic plants can easily become endangered if their habitat changes • Changes are mainly due to the actions of humans • The seeds of these plants have great potential • Can be used for many purposes
FYNBOS VEGETATION • Of the 9000 species in the fynbos vegetation zone of south western South Africa 6 200 are endemic • 1 000 are endangered • Many of the endemic species are extinct
Endemic: Organisms that are native and can be found ONLY in that location. Indigenous: Organisms that are native but can be found elsewhere.
In biogeography, a species is defined as native (or indigenous) to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism (as opposed to a domesticated organism) has its own natural range of distribution in which it is regarded as native. Outside this native range, a species may be introduced by human activity; it is then referred to as an introduced species within the regions where it was anthropogenically introduced. An indigenous species is not necessarily endemic. In biology and ecology, endemic means exclusively native to the biota of a specific place. An indigenous species may occur in areas other than the one under consideration.
PAGE 66 AND 67 To maintain the supply of these plants it is important to Have a good supply of seeds
TO DO • TEXTBOOK PAGE 68 LEARNING ACTIVITY 21 SHORT QUESTIONS
THE END SEED BANK