The Grass Family

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The Grass Family

• 8500 different species
• Dominant vegetation in many areas
• Monocots, often with horizontal stems
• Tiny, numerous flowers

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Fruit is the grain
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Corn (Maize)

• Zea mays
• New World staple
• Unusual flowers

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Zea mays
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Hybrid Corn

• Important crop in US
• Importance of hybrids to productivity
• Hybrids result from crossing inbred lines
• Hybrid vigor

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Consequences of hybrid corn

• Increased yields

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Consequences of hybrid corn

• Susceptibility to diseases
• male sterile lines
• Southern corn leaf blight

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Consequences of hybrid corn

• Increased yields
• Dependence on seed companies
• lots of heterozygosity
• seeds dont breed true

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Indian corn and Barbara McClintock

• Transposable genetic elements
• Jumping genes
• Idea of selfish DNA

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Types of maize

• Popcorn
• exploding kernels
• Sweet corn
• sugary endosperm
• Flint corn
• cornmeal, grits, animal food
• Flour corn
• soft endosperm, tortilla
• Dent corn
• most widely grown
• hard and soft endosperm

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Corn and nutrition

• Niacin is a vitamin required for making energy
• Corn has niacin, but its not available
• Can be made from tryptophan (an amino acid)
• Corn is low in tryptophan
• Resulting disease is pellagra
• Rough skin, dizziness, GI problems eventually
  death
• Native people of Mexico, Central America ate lots
  of corn, but had no pellagra
• Why?

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Masa harina

• Soft corn flour
• Soaked in lime (probably originally from ashes)
• Releases the thiamine
• Also combined with beans, squash, which have
  thiamine

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Where did corn come from?

• No wild corn known

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Rice

• Feeds more people than any other crop
• Grown almost exclusively for people
• Oryza sativa most commonly grown species

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• Originated in Asia
• Often grown in paddies

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• Paddy rice often is grown with a fern (Azolla)
• The fern is symbiotic with a cyanobacterium
• This provides natural nitrogen to the rice

Azolla in Chinese pond
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Azolla, a fern with a symbiotic cyanobacterium
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Rice and nutrition

• White (polished) rice loses vitamin B1 (thiamine)
• Thiamine essential in breaking down carbohydrates
• Disease resulting called beriberi
• Many effects, cramping, fatigue, confusion,
  cardiac failure
• Brown rice prevents disease
• Thiamin is also in meats, other whole grains

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Golden rice

• Vitamin A has several roles in vision, pigments
  in photoreceptors, but also prevents drying of
  epithelium
• Deficiency causes xerophthalmia, permanent
  blindness
• A dose of the vitamin every six months is enough
  to prevent blindness

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Wild rice

• Zizania aquatica
• Related to rice, but not that close
• New World plant

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Sake, rice wine

• A tradition at least 2000 years old
• More in common with beer brewing
• Starts with starchy grain (rice) which is
  polished
• Starch has to be converted to sugar
• Used to be done by chewing
• Nowadays, koji is used

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Kojia fungus

• Aspergillus oryzae
• Same fungus used in soy sauce and miso (bean
  products)
• Breaks starch to sugar

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Sake

• Then yeasts ferment the sugar to alcohol
• Many local varieties

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Other Grains

• Rye
• former weed of wheat
• easy to grow in bad soil or bad weather
• peasant grain
• Oats
• historically for horses
• recent interest because of cholesterol lowering
  possibilities

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• Sorghum (related to corn)
• important in Africa and India
• can be used for syrup or animal food
• Millet
• used in US for bird food
• used by people in India and Egypt

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Other grasses

• Forage grasses
• grown for stems and leaves
• may be cut as hay or silage
• Lawn grasses
• Sugar cane

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Nutrition in Grains

• Wheat--13 protein
• whole grain vs refined
• Corn--7-10 protein
• low in niacin (bound) and tryptophan
• not a problem in traditional diets of Mexico
• lime preparation, and combination with beans
• Rice--5-10 protein
• polished vs brown rice
• thiamine (B1) deficiency in polished
• beriberi