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Food Plants. Modern Day Inuit - Greenland. Contemporary Hunter-Gatherers The San Bushmen. Torres Straits Islands. Origin of Domesticated Plants. Wheat. Most domesticated food plants have been selected for:. large plant parts soft edible tissue thick flesh with intense color
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Most domesticated food plants have been selected for: • large plant parts • soft edible tissue • thick flesh with intense color • fruits attached to tough stems
How much domestication? • About 5000 species have been grown for human food – less than 1% of all plant species • Today about 150 species are commercially grown for food (not including spices) • About 50 very productive species supply almost all of our caloric needs
Benefits of Domestication • 10,000 years ago, before agriculture began, the world’s total human population was about 5 million. There was one person for every 25 square kilometers. Today we have more than 7.5 billion people, with a density of just over 47 people per square kilometer of land on Planet Earth
As agriculture developed humans selected for: 1. Plants that provide enough calories to meet our basic energy needs. This usually comes from cereal grain or root carbohydrates. 2. We also selected for a balanced nutritional intake - this tends to develop in any system where the cultivator eats and depends upon on what he/she grows.
Vavilov centers – centers of plant diversity and areas of origin for agriculture
Plants from Near East – Fertile Crescent • barley (Hordeum vulgare) • wheat (Triticum) • lentils (Lens culinaris) • peas (Pisum sativum) • chickpeas or garbanzos (Cicer arietinum) • olives (Olea europaea) • dates (Phoenix dactylifera) • grapes (Vitis vinifera) - Wine began to be made from the grapes and beer from the grains • flax (Linum usitatissimum) – food and fiber
Plants from China, Far East • Millet – several species of cereal grains • Rice (Oryza sativa) • Soybeans (Glycine max) • Mango (Mangifera indica) • Various kinds of citrus fruits (Citrus sp.) • Taro (Colocasia esculenta) • Bananas (Musa x paradisiaca)
Plants from Africa • sorghum (Sorghum sp.) • millet grains (several species) • okra (Hibiscus esculentus) • yams (Dioscrorea sp.) • cotton (Gossypium sp.) • Coffee (Coffea arabica)
corn (Zea mays), kidney beans (Phaseolus vulgaris) lima beans (P. lunatus) peanuts (Arachis hypogaea) cotton (developed independently from Africa) chili peppers (Capiscum sp.) tomatoes (Lycopersicon sp.) tobacco (Nicotiana tabacum) cacao (Theobroma cacao) pineapple (Ananas comosus) Pumpkins, squashes (Cucurbita sp.) avocados (Persea americana) Plants from Mexico
Plants from Peru • potato (Solanum tuberosum and many related species) • quinoa (Chenopodium quinoa) • tomatoes and peanuts may have really originated in Peru and then been taken to Mexico
Corn – Zea mays
Variation in ear size and kernel color fromMexican landraces of corn
Zea mays subsp. mexicana Zea mays subsp. mays
Teosinte vs. Corn Growth Teosinte Corn
Teosinte – Zea diploperennis
Maize productivity • Maize is tremendously productive - a typical Iowa cornfield will produce 3500 - 4000 g of carbon per meter squared per year - The most productive tropical rainforest or coastal salt marsh produce about 3500 g of carbon per meter squared per year
Maize productivity • Maize is so valuable because it is productive across a huge range of conditions – temperate to tropical (following adaptation to different day lengths) • Among modern cereal grains it is the most efficient in converting water and carbon dioxide into grains of food • However, it requires large amounts of nutrients and current high yields such as occur in farm land around here require the input of tremendous amounts of fertilizer
Cross section of corn leaf showing C-4 pathway