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

Figure 10-2

Origins of agriculture Ca ,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

Fig. 43.3a

Fig. 43.3b

Origin of Corn Arose from wild teosinte in southern Mexico ca 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

Modifications leading to different vegetables

Quiz on “how to tame a plant” 1)What plant, mentioned by the author, is conspicuous in its absence from the list of domesticated plants? 2)List three desirable traits of a plant that would make it a good candidate for domestication.