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Agriculture. Read “how to tame a wild plant”, for next time. Quiz on this Tuesday. Read Ch. 10, 11, 15. Human Nutritional Needs. Carbohydrates (simple, complex, fiber) Amino acids for proteins Essential (9 of 20); plant proteins “incomplete” Lipids (fats, oils, sterols, phospholipids)
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Agriculture Read “how to tame a wild plant”, for next time. Quiz on this Tuesday. Read Ch. 10, 11, 15
Human Nutritional Needs • Carbohydrates (simple, complex, fiber) • Amino acids for proteins • Essential (9 of 20); plant proteins “incomplete” • Lipids (fats, oils, sterols, phospholipids) • At least 3 essential; unsaturated • Vitamins (13 needed; 8-9 from plants: e.g., A, E, K, C, several “Bs”) • Minerals (17 or more; major & trace; Ca,Fe,I deficiency common) • *secondary compounds; e.g., medicinals
Origins of agriculture • Ca. 10-15,000 years ago • Arose in different areas • Utilized pre-adapted wild plants • (e.g., wheat, corn, pea, barley, lentel, rice) • Allowed for settlements and increases in rates of “advancement” in civilization
Origin of Corn Arose from wild teosinte in southern Mexico ca. 9000 years ago Only a few (5) mutations required for this (e.g., loss of fruitcase, silica & lignin accumulation, branching pattern = 2 genes) Humans selected for desirable mutations of propogated teosinte (= artificial selection) All modern corn from a founding bottleneck of 10 generations and 20 plants from a single domestication event of subspecies parviglumis From 6000 to 3000 y.a., selection increased cob size By 4400 y.a., a homogeneous superior widely-used crop corn existed
Corn continued • Now we have sweet, feed, sugar & oil corn • Genetically modified corn (e.g., to resist pests) • Development of acid-tolerant cultivars and corn with higher lysine & tryptophan
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.