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Germplasm...is both the genetic material (genes, groups of genes, chromosomes) that controls heredity and the tissues, organs, and organisms which express variation Contained in that genetic material 1
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Introduction of new plantsIntroduction of new plants Food, fiber, medicinal or ornamentalFood, fiber, medicinal or ornamental Changing diets: introduction of the potatoChanging diets: introduction of the potato ModificationModification Plants collected in wild often have limited value per sePlants collected in wild often have limited value per se We want adaptation to new environmentsWe want adaptation to new environments Changes in size, color number of different tissuesChanges in size, color number of different tissues We want those changes to have a genetic basis (heritable)We want those changes to have a genetic basis (heritable) Germplasm is the raw material for diversity which is the basis for selection (plant breeding)Germplasm is the raw material for diversity which is the basis for selection (plant breeding) Why are genetic resources important ? 2
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Diversity in Brassica Hundreds of different species Six (6) species are cultivated The two most common are: –B. oleracea –B. rapa 3
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Centers of Diversity 4 Brassica rapa oleracea
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B. oleracea Cabbage - var. capitata Cabbage - var. capitata - Domesticated from Kale (non-heading) - Cultivated for medicinal purposes - hard headed types developed about 800 AD - Red cabbage described in 1570 in England Cauliflower - var. botrytis Cauliflower - var. botrytis - Evolved from broccoli - 6th century B.C. Broccoli - var. italica Broccoli - var. italica - Domesticated from wild cabbage - Grown by Greeks and Romans, introduced into England 16th century, later introduced into U.S. in early 19th century. 5
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The part of the plant of greatest interest to man is the part that is modified the most. - J.R. Harlan 6
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Brassica oleracea selection results in six different vegetables 7 Kale Leaves Cabbage Terminal bud Cauliflower inflorescence Brussels sprouts Lateral buds Broccoli Flowers and stems Kohrabi Stem
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Six vegetables 8 Kale Broccoli Cauliflower Kohlrabi Brussel sprouts Cabbage
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cabbages 9 Red Savoy For fresh market as savoy type is hard to clean
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Broccoli 10 Produced in winter in Salinas Valley of California Production and consumption has tripled since 1970 The tissue we consume is the young inflorescence and flowering buds. The flower primordia are united into clusters Buds are functional flowers
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Cauliflower 11 Consists of a dense mass of branched floral structures The edible portion is a thickened fleshy inflorescence As the inflorescence ages, there is rapid elongation. To produce functional flowers axillary buds are formed
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B. rapa common members 12 Rab Turnip Bok-choy napa
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Pak Choy B. rapa var. chinense 13 White fleshy petioles minimal vernalization required for bolting less temperature sensitive than Chinese cabbage, thus, wider adaptation
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Chinese cabbage B. rapa var. pekinensis Chinese cabbage B. rapa var. pekinensis 14
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Non-heading Chinese cabbage B. rapa var. pekinensis 15
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Fast Plant 16 Dr. Paul Williams - UW r. Brassica rapa Flowers in 16 days Harvest seed in 35 days Plants are 10-12 cm tall Can be planted in a plastic soda pop bottle
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17 The world's food supply is based on intensive agriculture, which relies on genetic uniformity. But this uniformity increases crop vulnerability to pests and stresses. GERMPLASM tissues, organs, seeds, genes, groups of genes any material that carries hereditary information
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18 Scientists need access to genetic diversity to breed varieties that can resist pests, diseases, and environmental stresses. The National Plant Germplasm Service (NPGS) aids the scientists and the need for genetic diversity by: acquiring crop germplasm preserving crop germplasm evaluating crop germplasm documenting crop germplasm distributing crop germplasm NPGS is a cooperative effort by public (State and Federal) and private organizations to preserve the genetic diversity of plants.
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19 Many important crop species originate outside the United States You can order germplasm ! (usually free) New germplasm (accessions) enter NPGS through collection, donation by foreign cooperators or international germplasm collections. The germplasm is evaluated, maintained, and made available for distribution. Go to Summary statistics http://www.ars-grin.gov/index.html
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20 The Controversy: Who owns the germplasm? Who should benefit from research to improve a plant species by breeding and/or genetic engineering?
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