germplasm
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
GermplasmGermplasm
...is both the genetic material ...is both the genetic material (genes, groups of genes, chromosomes) (genes, groups of genes, chromosomes) that controls heredity and the tissues, organs, that controls heredity and the tissues, organs, and organisms which express variation and organisms which express variation Contained in that genetic materialContained in that genetic material
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• Introduction of new plants Introduction 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 Plants collected in wild often have limited value per seper 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 Germplasm is the raw material for diversity which is the
basis for selection (plant breeding)basis for selection (plant breeding)
Why are genetic Why are genetic resources important ?resources important ?
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Diversity in BrassicaDiversity in Brassica
• Hundreds of different species
• Six (6) species are cultivated
• The two most common are:– B. oleracea– B. rapa
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B. oleraceaB. oleracea B. oleraceaB. oleracea
• • Cabbage - var. capitataCabbage - var. capitata- Domesticated from Kale (non-heading)- Domesticated from Kale (non-heading)
- Cultivated for medicinal purposes- Cultivated for medicinal purposes
- hard headed types developed about 800 AD- hard headed types developed about 800 AD
- Red cabbage described in 1570 in England - Red cabbage described in 1570 in England
• • Cauliflower - var. botrytisCauliflower - var. botrytis- Evolved from broccoli- Evolved from broccoli
- 6th century B.C. - 6th century B.C.
• • Broccoli - var. italicaBroccoli - var. italica- Domesticated from wild cabbage- Domesticated from wild cabbage
- Grown by Greeks and Romans, introduced into England 16th - Grown by Greeks and Romans, introduced into England 16th century , later introduced into U.S. in early 19th century. century , later introduced into U.S. in early 19th century.
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The part of the plant of greatest interest to man The part of the plant of greatest interest to man
is the part that is modified the most. - J.R. is the part that is modified the most. - J.R.
HarlanHarlan
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Brassica oleraceaBrassica oleraceaselection results in six different vegetablesselection results in six different vegetables
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KaleLeaves
CabbageTerminal bud
Cauliflowerinflorescence
Brussels sproutsLateral buds
BroccoliFlowers and stems
KohrabiStem
Broccoli Broccoli 1010
• 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
Cauliflower Cauliflower 1111
• 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
Pak ChoyPak ChoyB. rapa var. chinenseB. rapa var. chinense
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• White fleshy petioles
• minimal vernalization required for bolting
• less temperature sensitive than Chinese cabbage, thus, wider adaptation
Non-heading Chinese cabbageNon-heading Chinese cabbageB. rapa var. pekinensis B. rapa var. pekinensis
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Fast PlantFast Plant1616
• 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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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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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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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