Origin of Domesticated Plants Wheat Most domesticated food

Origin of Domesticated Plants Wheat

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 thought to exist • 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 billion people, with a density of just over 25 people per square kilometer

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.

Dog Domesticated circa 20, 000 YA – shown in Egyptian painting – 4500 BCE

Neolithic European Thatch Houses

Vavilov centers – centers of plant diversity and areas of origin for agriculture

Plants from Near East – Fertile Crescent • • Barley - Hordeum vulgare Wheat - Triticum spp. 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

Barley

Lentils

Chickpeas

Date Palm

Flax

Malus sieversii – wild apple from Kazakhstan

Malus sieversii - Flowers

Malus sieversii - Fruits

Plants from China, Far East • • Millet grains - several species Rice - Oryza sativa Soybeans - Glycine max Mango - Mangifera indica Various kinds of citrus fruits - Citrus sp. Taro - Colocasia esculenta Bananas - Musa x paradisiaca

Rice

Mango

Taro

Plants from Africa • Sorghum - Sorghum sp. • Millet grains - several species (these developed independently of China) • Okra - Hibiscus esculentus • Yams - Dioscrorea sp. • Cotton - Gossypium sp. • Coffee - Coffea arabica

Sorghum and Millet

Okra

Yams

Coffee

Plants from Mexico • Corn (Maize) - 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

Kidney Beans

Peanut

Chili Peppers – Capiscum sp.

Pumpkins and Squashes

Plants from Peru • Potato -Solanum tuberosum and many related species • Quinoa - Chenopodium quinoa • Amaranth – Amaranthus (3 species) • tomatoes and peanuts may have really originated in Peru and then been taken to Mexico

Potato

Quinoa

First ethnobotanical rule of food production • In indigenous agriculture where the crops are consumed and not sold, there evolves and is maintained a reasonable level of nutritional adequacy

Second ethnobotanical rule of food production • In indigenous agriculture where the crops are grown mainly or only for sale, there develops an expanding surplus of food. The overall objective of such agricultural systems is to replace a pre-existing (natural) plant community with a cultivator-made community

It then follows that: If the potentially unstable increase in food production and human population is to be maintained, it must be consistent with three aims: 1. To operate at a maximum profit (labor/yield). 2. To minimize year-to-year instability in production. 3. To operate so as to prevent long-term degradation of the production capacity of the agricultural system.

Mexican Corn Growing

Mexican Corn Varieties

Squanto and Pilgrims

North Eastern Native American Groups

Three Sisters Mound System

Three Sisters Mound System

Three Sisters Planting Scheme

Benefits of Three Sisters Mounds • In the Northeast where ground was frequently cold and damp in early spring, mounds allowed the soil to warm up and drain more quickly • Mounds allowed an increase in soil organic matter by repeatedly incorporating dead plant material with soil in mounds • Decomposition of dead plant material increased soil nutrients; also growing beans which are N-fixers increased soil N for all plants in the mound • Mounds minimized soil compaction (people did not walk on mounds, but around them) and reduced soil erosion as fields were not constantly plowed or dug up • Mound system allowed easy regulation of plant spacing and plant populations

Darwin on Artificial Selection “Although man did not cause variability and cannot even prevent it, he can select, preserve, and accumulate the variations given to him by the hand of nature almost in any way which he chooses; and thus can certainly produce a great result… Selection by man may be followed either methodically and intentionally, or unconsciously and unintentionally… We can further understand how it is that domestic races of plants often exhibit an abnormal character, as compared to natural species, for they have been modified not for their own benefit, but for that of man. ”

The Green Revolution • The Green Revolution refers to the transformation of agriculture that began in 1945, largely due to the life work of Norman Borlaug. One significant factor in this revolution was the Mexican government's request to establish an agricultural research station to develop more varieties of wheat that could be used to feed the rapidly growing population of the country.

Norman Borlaug

Green Revolution Advances • The main technological development of the Green Revolution was the production of novel wheat cultivars. Agronomists bred cultivars of maize, wheat, and rice that are generally referred to as HYVs or “high-yielding varieties”. HYVs have higher nitrogen-absorbing potential than other varieties. Since cereals that absorbed extra nitrogen would typically lodge, or fall over before harvest, semi-dwarfing genes were bred into their genomes. A Japanese dwarf wheat cultivar (Norin 10) wheat was instrumental in developing Green Revolution wheat cultivars. IR 8, the first widely implemented HYV rice to be developed by IRRI, was also a dwarf variety.

Progression of Wheat Dwarfism

Development of Rice Dwarfism

Increase in global corn production

Increase in Big 3 Grains

US Corn Production and Climate

Criticisms of Green Revolution • High yields lead to unsustainable increases in human population – like Ireland potato • HYV grains require high fertilizer inputs and mechanized agriculture – benefits large farmers, agribusiness but not small farmers • Change in diet quality – Green Revolution favors cereal grain monocultures; traditional agriculture is polyculture with many species and high nutrient diversity

Spread of Southern Corn Leaf Blight

Southern Corn Leaf Blight

Close up of Southern Corn Leaf Blight

Southern Corn Leaf Blight – damage to ear

Seed Savers, Decorah, Iowa

Seed Savers, Decorah, Iowa

Stowe, England – Apple Festival

Stowe, England – Apple Festival

Stowe, England – Apple Festival