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1. 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. 2. Why are genetic resources important ?. Introduction of new plants
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1 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
2 Why are genetic resources important ? • Introduction of new plants • Food, fiber, medicinal or ornamental • Changing diets: introduction of the potato • Modification • Plants collected in wild often have limited value per se • We want adaptation to new environments • Changes in size, color number of different tissues • 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)
3 Diversity in Brassica • Hundreds of different species • Six (6) species are cultivated • The two most common are: • B. oleracea • B. rapa
4 Centers of Diversity Brassica oleracea rapa
5 B. oleracea • • 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 • - Evolved from broccoli • - 6th century B.C. • • 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.
6 The part of the plant of greatest interest to man is the part that is modified the most. - J.R. Harlan
7 Brassica oleraceaselection results in six different vegetables Kale Leaves Cabbage Terminal bud Cauliflower inflorescence Brussels sprouts Lateral buds Broccoli Flowers and stems Kohrabi Stem
Six vegetables 8 Cabbage Kale Brussel sprouts Broccoli Kohlrabi Cauliflower
9 cabbages For fresh market as savoy type is hard to clean Savoy Red
10 Broccoli • 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
11 Cauliflower • 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
12 B. rapacommon members Turnip Bok-choy napa Rab
13 Pak ChoyB. rapa var. chinense • White fleshy petioles • minimal vernalization required for bolting • less temperature sensitive than Chinese cabbage, thus, wider adaptation
14 Chinese cabbageB. rapa var. pekinensis
15 Non-heading Chinese cabbageB. rapa var. pekinensis
16 Fast Plant • 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 • •
GERMPLASM • tissues, organs, seeds, genes, groups of genes • any material that carries hereditary information 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.
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.
Many important crop species originate outside the United States 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. You can order germplasm ! (usually free) http://www.ars-grin.gov/index.html Go to Summary statistics
The Controversy: Who owns the germplasm? Who should benefit from research to improve a plant species by breeding and/or genetic engineering?