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Quiz on “how to tame a plant”. What plant, mentioned by the author, is conspicuous in its absence from the list of domesticated plants? List three desirable traits of a plant that would make it a good candidate for domestication. Agriculture- Part II. Modern agriculture -Ohio & NW Ohio
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Quiz on “how to tame a plant” • What plant, mentioned by the author, is conspicuous in its absence from the list of domesticated plants? • List three desirable traits of a plant that would make it a good candidate for domestication.
Agriculture- Part II Modern agriculture -Ohio & NW Ohio -Problems -Biotechnology
Ohio Agriculture • See overheads & file (ohio ag facts)
Crop loss in the U.S. (1982) Croprecord yieldaverage yield (=21%) corn 19300 4600 wheat 14500 1880 soybeans 7390 1610 oats 10600 1720 sorghum 20100 2830 barley 11400 2050 potatoes 94100 28300 s. beets 121000 42600
% of crop loss due to: • Diseases = 4.1 (U.S. lower than elsewhere) • Insects = 2.6 • Weeds = 2.6 • Unfavorable environment = 69.1 • 40% of this to drought • 20% to flooding • 14% to cold
Crop development • Occurring since domestication of plants • Through artificial selection • Use of hydrids & grafting • Propogation of desirable genotypes • Homogenizing individuals • To transgenic plants
The Green Revolution • Has increased yields 2-4x over ca. 50 years • Using high-yield disease-resistant varieties + lots of: • fertilizer, pesticides, herbicides, mechanization, & irrigation • mainly corn, wheat, & rice • Dr. Norman Borlaug • Father of GR; dwarf & disease-resistant wheat; Nobel Peace Prize 1970 • Sustainable? Fairly available?
Transgenic crops • Most are either GM for: • herbicide tolerance (glyphosphate=Round-Up) (poisons shikimic-acid pathway, so plants & fungi, but not animals) • insect resistance (Bacillus thuringiensis genes) (range of insecticidal proteins, but doesn’t kill vertebrates; reduces use of pesticides) • or both • See overheads
Some “hot topics” in agriculture • Transgenics* • Non-plant products from plants* • Phytoremediation* • Developing new crops* • Enhancing crop quality* • Increasing crop water & nutrient use efficiency • Increasing stress tolerance (temp, drought, salt) • Preserving crop genetic diversity for the future* • Development of resistant weeds and pests • Environmental damage (e.g., from run-off)
Transgenic concerns Human health risks? Allergic reactions from non-plant proteins? [Mostly minor] Philosophical issues? e.g., Europe Developing-country concerns? Have to buy seeds, pesticides, etc., from company; intellectual property rights Gene escape? [YES, and it’s not reversible!] Due to hybridization, pollen flow, & human error/disregard. No fail-safe method to stop. Superweeds? [YES…already happening!] (article) Toxic effects on non-target organisms? [Minor?] e.g., monarch butterflies
Non-plant products • Using transgenic techniques to create plants that make non-plant substances • E.g., edible or huge-volume of human medicines, plastics (see Botany global issues map), fuel oil, etc. • See overhead
Phytoremediation • Using grasses, trees, herbs (e.g., mustards), ferns, crops (see Botany global issues map) • Remove soil/water contaminants and accumulate in tissues (e.g., shoots) • Remove plants & dispose • Can use for a wide range of substances • (e.g., metals, radioactivity, organics) • Can require site-specific research
Developing new crops • Amaranth • Eastern gama grass • Quinoa • Oca • Tarwi
Enhancing crop quality • Increasing oil or protein content e.g., in corn and soybean • Changing protein/oil composition Lysine & tryptophan in corn (BGI map) • Increasing mineral or vitamin content Carotene (Vit A) in golden rice (BGI map) (50% of humans get 80% of calories from rice) Work underway on high-Fe crops
Irrigation • Makes soil salty • Uses fresh water
*most major crops have only a few cultivars in use *so high risk to disaster loss *most natural variation for crops is lost *seed/germplasm banks keep genetic variation for safety