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GENETIC RESOURCES: Resources that contain all genetic variability found in a particular plant species This includes its wild relatives; m ost of them.

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Presentation on theme: "GENETIC RESOURCES: Resources that contain all genetic variability found in a particular plant species This includes its wild relatives; m ost of them."— Presentation transcript:

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2 GENETIC RESOURCES: Resources that contain all genetic variability found in a particular plant species This includes its wild relatives; m ost of them may have traits useful to breeders. GERMPLASM: Overall genetic materials possessed by the plant species

3 Categories of Genetic Resources (Hawkes, 1983) Crops i. Current commercial cultivars. ii. Old commercial cultivars - no longer planted commercially. iii. Breeders’ seeds. iv. Mutants from induced or spontaneous mutations. Land Race Usually from isolated areas or farms. Primitive crops, usually possessing high variations and grown in mixtures of genotypes, and sometimes species.

4 Categories of Genetic Resource (Cont.) Weedy Race Plants that originated from same progenitor of the crop species, but possess weedy traits, such as small stem. Capable of invading open fields rapidly, even with low soil fertility.

5 Wild species Species from the same genus that could be crossable to a certain crop species. Categories of Genetic Resources (Cont.)

6 Vavilov (1887-1941), a Russian botanist studied diversity and distribution of plants in the world from 1920’s to 1930’s, and found that: There are higher levels of diversity in certain parts / regions in the world for certain kinds of plant. Revealed eight centres of origin for main crops. CENTRES OF ORIGIN AND CENTRES OF PLANT DIVERSITY

7 Cereal and legumes: eg: Soybeans (Glycine max) Roots, vegetables eg: Radish(Raphanus sativus) chinese cabbage (Brassica rapa chinensis) Fruits and nuts eg: Oranges (Citrus sinensis), litchi (Litchi chinensis) Sugar, drug plants eg: Tea (Camellia sinensis), sugar cane (Saccharum sp.) 1. Chinese Center (China)

8 Distribution and origin of plants

9 2. Indian Center Cereal and legumes eg: Rice (Oryza sativa), chick pea (Cicer arietinum) Vegetables and tubers eg: Egg plant (Solanum melongena) Cucumber (Cucumis sativus) Sugar, oil, fiber plants eg: sugar cane (Saccharum spp.), kenaf (Hibiscus cannabinus) Spices eg: Black pepper(Piper nigrum)

10 Distribution and origin of plants

11 2a. Indo-Malayan Center Fruits eg: Pomelo (Citrus maxima), Banana (Musa spp.) Coconut (Cocos nucifera), mangosteen (Garcinia mangostana), Durian (Durio zibethinus) Oil, sugar, spice plants eg: Nutmeg (Myristica fragrans),Cloves (Syzygium aromaticum)

12 3. Central Asiatic Center Grains and legumes eg: Wheat(Triticum aestivum), Pea (Pisum sativum) Vegetables eg: Carrot (Daucus carota), spinach (Spinacia oleracea) Fruits eg: Apple (Malus pumila), grape (Vitis vinifera)

13 Distribution and origin of plants Central Asia

14 4. Near Eastern Center Grain and legumes eg: Wheat (Triticum aestivum), Barley (Hordeum vulgare) Fruits eg: Melon (Cucumis melo), Pomegranate (Punica granatum) Forage plants eg: alfalfa (Medicago sativa)

15 Distribution and origin of plants Near East

16 5. Mediterranean Center Cereal and legumes eg: Wheat (Triticum durum), oats (Avena sativa), Broadbean (Vicia faba) Oil and fiber plants eg: Olive (Olea europaea), black mustard (Brassica nigra) Vegetables eg: Cabbage (Brassica oleracea) Ethereal oil and spices eg: peppermint (Mentha spp.), thyme (Thymus mongolicus)

17 Distribution and origin of plants

18 6. Abyssinian/Ethiopian (African) Center Grains and legumes eg: Wheat (Triticum durum), Barley (Hordeum vulgare) Misc: Coffee (Coffea arabica), okra (Abelmochus esculentus) Oil palm (Elaeis guineensis)

19 Distribution and origin of plants / Ethiopian (African )

20 7. South Mexican and Central American Center Grain and legumes eg: Corn (Zea mays), Common bean (Phaseolus vulgaris) Melon plants eg: Pumpkin (Cucurbita spp.) Misc: Chilli (Capsicum annum), cocoa (Theobroma cacao )

21 Distribution and origin of plants South Mexican & Central American Center

22 8. South American (Peruvian- Ecuadorean-Bolivian) Center Root tubers eg: Sweet potato (Ipomoea batatas), Potato (Solanum tuberosum) Vegetable crops eg: Tomato (Solanum lycopersicum) Fruits and misc eg: Papaya (Carica papaya), Tobacco (Nicotiana tabacum)

23 Distribution and origin of plants

24 8a. Chilean Center Potato (Solanum tuberosum) Distribution and origin of plants

25 8b. Brazilian-Paraguayan Center Cassava (Manihot esculenta) Groundnut (Arachis hypogea) Cocoa (Theobroma cacao) Rubber (Hevea brasiliensis) Pineapple (Ananas comosus) Passion Fruit (Passiflora edulis)

26 Distribution and origin of plants

27 GERMPLASM CONSERVATION  Deforestation – Lost of wild species and weedy races.  Use of modern varieties – Lost of land races, primitive crops and weedy races.  Development –Lost of land races, primitive crops varieties, etc. Therefore, conservation is needed to conserve crop genes and genotypes, to prevent genetic vulnerability Erosion or loss of genetic resources happened and is continuously happening at a serious rate due to:

28 STEPS IN GERMPLASM CONSERVATION 1. Exploration Exploration is done to understand the crop distribution. Plant collection is conducted to obtain samples that consist the maximum genetic diversity. Where? Native habitats of selected crop Farm where crop is planted, including small farm Market Other entities/ institutions

29 2.Collection Random sampling To obtain variation that represents population of the crop. Selected sampling Done for plants with specific character. The collection may not represent the actual variation. Therefore, selected sampling has to be done concurrent with random sampling. STEPS IN GERMPLASM CONSERVATION (cont.)

30 STEPS IN GERMPLASM CONSERVATION (Cont.) 3.Maintenance / Conservation a) In situ – grown in natural habitat Maintain the original forest ecosystem, grassland, Vavilov’s centre of diversity, forest parks.

31 3. Maintenance / Conservation (Cont.) b)Ex-situ Collections Seed bank Requirement: Cold room, 10 o C Relative Humidity, 2-5% Living Plants Botanical Gardens Arboretum Field genebanks Maize seed bank arboretum

32 3. Storage (Conservation) b)Ex-situ (Cont.) Pollen storage Requirement: Cold room, 10 o c to - 20 o c Relative Humidity, 8 -25% In-vitro method - Tissue culture– slow growth - Cryopreservation- Liquid nitrogen (-196 o c)


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