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.

Agriculture- Part II Modern agriculture -Ohio & NW Ohio -Problems -Biotechnology

Fig. 14.1

Ohio Agriculture See overheads & file (ohio ag facts)

Crop loss in the U.S. (1982) Croprecord yieldaverage yield (=21%) corn wheat soybeans oats sorghum barley potatoes s. beets

% 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

Fig. 14.7a

Fig. 14.7b

Fig

Fig a

Fig b

Fig

Fig

Fig

Fig

Fig

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?

Fig. 14.9

Fig

Fig

Fig

Fig

Fig

Fig

Fig

Fig

Fig

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