Thursday Lecture – Legumes continued : Thursday Lecture – Legumes continued Reading: Textbook, Chapter 6
Legumes – Changes Under Domestication : Legumes – Changes Under Domestication Annual habit, selfing breeding system
Less seed scattering
Greater seed size
Synchronous fruiting
Loss of dormancy
- question: which came first, domestication or loss of dormancy?
Major Legume Food Crops - Pulses : Major Legume Food Crops - Pulses Pulses: dried legume seeds used for food Near East: lentils, peas, chick-peas, broad beans
Far East: soybean, pigeon pea
Africa: cowpeas
Mexico: common bean, lima bean
South America: common bean, lima bean, peanut
Near Eastern Pulses – 1. Lentils : Near Eastern Pulses – 1. Lentils Lens culinaris – genus name refers to shape of seeds
Near Eastern Pulses – 2. Peas : Near Eastern Pulses – 2. Peas Pisum sativum – used as food since ancient times (8-9,000 yrs ago) and domesticated by about 5,800 yrs ago.
Peas – porridge or green : Peas – porridge or green Pease porridge hot
Pease porridge cold
Pease porridge in the pot
Nine days old 1600s – first use as fresh green vegetable (Holland)
Specialized peas: snow peas, sugar snap peas – bred so that pods are edible in entirely, have high sugar levels
Near Eastern Pulses – 3. Broad Beans : Near Eastern Pulses – 3. Broad Beans Vicia faba – from Mediterranean region, cultivated 8800 yrs ago.
Favism – type of anemia, aggravated in susceptible individual by Vicia alkaloids
Near Eastern Pulses – 4. Chick-Peas : Near Eastern Pulses – 4. Chick-Peas
“cow-without-bones” - soybean : “cow-without-bones” - soybean Glycine max – domesticated in China >3000 yrs ago.
The “Cinderella Crop” : The “Cinderella Crop” U.S. – introduced as crop in 1765
1920s – used for fruit rather than just forage
Soybeans contain a trypsin inhibitor, destroyed by heating
Soybean Products : Soybean Products Oriental Foodstuffs: Miso, Tofu, Tempeh, Soy Milk, Soy Sauce
Soybean Oil – widely used
Soy proteins – used in many products
Soy lecithin – widely used in chocolate products
Non-food uses: inks, plastics, cleaners
Roundup - Glyphosphate : Roundup - Glyphosphate Herbicide – chemical structure: Mode of action: blocks synthesis of certain amino acids (aromatic amino acids produced by the shikimic acid pathway) Toxic to most plants, but not to animals
Note: can still be toxic to animals, not just the active chemical but other components of the formulation
Monsanto Chemical Company – major moneymaker – while under patent protection
Monsanto - post-Roundup : Monsanto - post-Roundup Next stage produce genetically modified crops that are resistant to glyphosphate
Source of resistance:
microorganisms, have enzyme that is resistant to glyphosphate
Microorganisms or plants, find enzymes that alter glyphosphate structure to make it harmless
Using (1) – Monsanto has created crops that are resistant to glyphosphate “Roundup Ready”
First Major Target: Soybeans, very successful
Can spray crop after germination, kill weeds but crop little affected
Roundup Ready Wheat : Roundup Ready Wheat The Latest Battlefield in the “Biotech Wars”:
Roundup Ready Crops: corn, soybeans, cotton
None of these have major use in human consumption
Roundup Ready Wheat: produced and marketed by Monsanto
major use of wheat = human food
major export crop ( Japan, Europe)
Worry: if any farmers grown GM Wheat, some importers (Japan) will ban all wheat from U.S. all farmers will lose this market
Other Old World Pulses : Other Old World Pulses Pigeon peas, Cajanus cajan – from India
Black-eyed peas (Cowpeas), Vigna unguiculata – from Africa, in U.S. considered to be southern regional specialty
New World Beans – 1. Lima Beans : New World Beans – 1. Lima Beans Phaeolus lunata – Mexico to Peru, independently domesticated in the two areas. Mostly used dry. Wild plants and some cultivars contain cyanogenic glycosides – release toxic cyanide (cooking destroys compounds)
New World Beans – 2. Common Beans : New World Beans – 2. Common Beans Phaseolus vulgaris – source of many types
Another independent domesticate in Mexico and South America
Beans, Beans, Beans : Beans, Beans, Beans Selection for the variations in the seed in color and size have produced a bewildering number of variants, several of which have widespread use in our country. Kidney bean Black bean Pinto bean
Another New World Legume - Peanut : Another New World Legume - Peanut Arachis hypogaea – peanut, ground nut, goober central South America
The Underground Crop : The Underground Crop
Forage Legumes – Sitting in the Clover : Forage Legumes – Sitting in the Clover Alfalfa – Medicago sativa - king of forage crops – associated with horse husbandry
Clovers – Trifolium
Sweet Clovers – Melilotus
Lespedeza
Tuesday Lecture – Leaf, Stem and Root Crops : Tuesday Lecture – Leaf, Stem and Root Crops Reading: Textbook, Chapter 7