Agriculture
• Humans shifted
from huntergatherer to farmer
about 12,000 yrs
ago
• Happened almost
simultaneously
around the world;
three major centers
were around the
Middle East (‘fertile
crescent’), Eastern
China, and India
Impact of farming
•
1.
2.
3.
4.
5.
Farming changed human society
forever
To farm, you need fertile ground for
long periods: this kept people in one
spot
One spotvillages
Villagesstructure/rules
Rulesto stable civilizations
Stable civilizationsadvancements
Domestication
•Stability allowed long-term
domestication of plants & animals
•Domestication occurred by selective
breeding; all modern crops derived
from wild relatives (same with cows,
chickens, etc.)
•Domestication not easy—but
produces more in long run
Top Agricultural Crop Families
• Grass family (Poaceae)—rice, wheat, corn,
etc.
• Tomato family (Solanaceae)—tomatos,
potatoes, peppers, eggplants
• Bean family (Fabaceae)—soybeans, peas,
beans
• Cabbage family (Brassicaceae)—cabbage,
mustard, turnips, broccoli
• Melon family (Cucurbitaceae)—watermelon,
honeydews, squash, zucchini
• Carrot family (Apiaceae)—carrots, celery,
parsnips, cilantro
Poaceae—Grass family
• Named for genus Poa
• Crops called cereal crops (Greek god of
agriculture was Ceres)
• Monocots
• Old family name: Graminae (=grains)
• Of the total food produced by the World's
top 30 crops (based on dry matter), about
23.4% comes from wheat, followed by
maize (21.5%) and rice (16.5%) (Harlan,
1995).
Poaceae
• ~70% of farmland dedicated to this
group
• 9,000 species worldwide
• 35 species domesticated, 5
important today
• Only 1 from New World—which
one?
Rice
Corn
Wheat
Sorghum, Millet
Sugar Cane
Oats, Rye
Grass vegetative structure
• Fibrous roots
• Leaves wrap
around stem
• Produces
clones (tillers)
from runners
(stolons) or
from rhizomes
Grass reproductive structure
• Highly modified
flower—no sepals,
no petals
• Protective leaves
(glumes) around
flower stem base
• Closer to each
flower, 2 more
protective leaves:
lemmas, paleas
• 1 carpel, 2 stigma
lobes, 3 stamens
Grass seeds:
• As seed matures,
fuses completely to
ovary
wall=caryopsis
(kernel)
• Ovary wall + seed
coat = bran
• Interior to seed coat
is oil-rich layer
called aleurone
layer
• Lots of endosperm
• 1-cotyledon =
monocot
Grass domestication:
•
•
•
•
•
Synchronicity
Tiller elimination
Height (reduced lodging & matting)
Shattering reduction
Easier threshing
•
•
•
•
Bean family
(Fabaceae)
2nd to grasses in economic
importance
Major crops: soybeans,
peanuts, beans, peas,
alfalfa, clover, chickpeas,
lentils
Old family name =
Leguminosae because
fruit type is legume
1-carpel flowers with many
seeds; dehiscent at
maturity
Fabaceae
• Rhizobium bacteria form symbiotic relationships with roots
• Produce nodules
Cucurbitaceae: melon family
• Cucumbers,
melons,
squashes,
zucchini,
gourds,
pumpkins,
loofahs
• Fruit
typepepo
• Some medicinal
uses: Chinese
abortions &
compound
tricosanthin
slows HIV
Apiaceae: carrot family
• Carrots,
parsnips, celery
• Herbs: chervil,
angelica, dill,
caraway,
coriander,
cumin, fennel,
parsely,
aniseed,
cilantro, rhubarb
• Old name:
Umbelliferae
Solanaceae:Family of Paradox
Plants in the Solanaceae
Food plants
Psychoactive plants
Ornamentals
Eggplants--OW
Mandrake--OW
Petunias
Potatoes--NW
Belladonna--OW
Peppers--NW
Henbane--OW
Tomatoes--NW
Tobacco--NW
Alkaloids of Solanaceae
plants:
• Atropine
from
belladonna
Nicotine
• 2 species:
Nicotiana
rusticum & N.
tabacum
Other common alkaloids:
• Scopolamine—used for motion
sickness
• Mandragorine—1st date-rape drug
• Hyoscyamine—hallucinogenic
Eggplants
• Native to India
• Domesticated
about 3,000 yrs
ago
• Original plants
produced egglike fruit
• Modern
varieties have
thicker, purple
skin
Peppers
3 main species, each with
many varieties:
Capsicum annuum
Capsicum frutescens
Capsicum chinense
The name “Capsicum”
could arise from the Latin
capsa (box) or the Greek
kapto (to bite).
Why are peppers so hot?
•produce the alkaloid capsaicin,
chemically similar to vanillin in
vanilla orchids
•capsaicin is the main ingredient in
pepper sprays
•humans can detect capsaicin in 8
parts per billion!!
•all the capsaicin is located in the
tissue that connects the pepper seed
to the ovary wall of the flower:
*The hottest pepper recorded was a Habanero.
Pure Capsaicin measures 16,000,000 Scoville units.
Pepper Facts:
• first appear in cave deposits in Mexico about 7000 BC
• a second, independent origin in South America by 5000 BC
• first European encounter: Columbus in 1494
• spread from Europe to Hungary (paprika) & to India, where peppers
became naturalized
• spread from Mexico to Louisiana & Texas in the 1850s after the
Mexican-American war
Little known pepper
anecdotes:
• Carib Indians’ usage: POW’s
• Aztec usage: punishment, airconditioning
• Incan usage: gas warfare
• Paprika, Szent-Gyorgyi, and the
Nobel Prize
•
•
•
•
•
•
•
Tomatos:
wolf-peaches
Lycopersicon
esculentum=‘wolf-peach
tasty’
Domesticated in Central
America
Nahuatl tribes called them
‘tomatl’
First record in Europe is 1544
in Italy
Called ‘love apples’ to boost
sales
Not eaten for centuries in
Europe because it looked like
local toxic cousins
Ketchup finally popularized
in early 1900s, salsa in the
1980s
Potatoes
• Domesticated in
mountains of Argentina
• Good crop for area—cool,
moist, underground
• Tuber=modified stem
• Biennial crops
• ‘eyes’ = axillary buds
• Native name ‘batatas’
• Natives first to discover
the process of freezedrying; used potatoes
Potatoes & history
• Irish potato famine—1840s—killed 1-6
million people—caused by potato
fungus Phytophthora
• Russians used potatoes as fermentation
sourcevodka
Asteraceae: sunflower family
• Composite/head
flowers
• Old name
Compositae
• Egyptians
domesticated by
5000BC!
• Columbus carried to
New World
• Crops: lettuce,
endive, chicory,
artichoke, sunflower
seeds/oil
Liliaceae: lily family
• Crops: onions,
garlic, leeks,
chives
• Domesticated
by Egyptians
6000BC—
garlic & onions
used for
mummification
& perfumes
Cabbage family: Brassicaceae
• Crops: cabbage, broccoli, cauliflower,
turnips, kale, collards, mustard, brussel
sprouts, rutabagas
Spices
• Phoenicians (2000BC-1000BC) cornered
market on spice trade from India to Spain
• Arabs took over spice trade to Europe
500AD-1000AD
• Spices more valued than gold, silver,
diamonds
• Value of spices started European exploration
~1100AD
• European food rather tasteless, also meat
rotted so spices covered up rotten part
Spices: Mint family
• Spearmint,
sage, basil,
rosemary,
thyme,
oregano,
peppermint
, marjoram
Spices: myrtle family
(Myrtaceae)
• Cloves, allspice
Spices: Saffron (Iridaceae)
• Saffron is world’s
most expensive
spice
• Saffron=stigma
lobes of purple
crocus
• 1 oz costs $36
Spices: ginger family
• Turmeric, cardamom, ginger
• Family Zingiberaceae (tropical)
Spices: Cinnamon
• Family Lauraceae
• Cinnamon is bark of
cinnamon tree
Spices: Licorice
• Licorice comes from bean
family, Fabaceae
• So does tamarind
Perfumes
• The basic ingredients are
odorants (=volatile oils)
that can be extracted
• Extracted with organic
solvents, alcohols, steam,
pressing oils, or heating with
alcohol
• Many compounds used in
perfumes are synthesized
• Blending of fragrances is an
art and producing a new
scent can cost $2-$3 million,
mostly for advertising
Fragrance or
Essential Oil
Perfume
Diluent
Perfume
20% to 30%
70% to 80%
Cologne
15% to 20%
80% to 85%
Eau de Cologne
12% to 17%
83% to 88%
Eau de Toilette
5% to 10%
90% to 95%
Aftershave
2% to 5%
95% to 98%
Formulation Type
Vegetable Oils
•
•
•
•
•
•
•
Canola AKA rapeseed (Brassicaceae)
Corn (Poaceae)
Peanut (Fabaceae)
Olive (Oleaceae)
Palm (Arecaceae)
Coconut (Areaceae)
Safflower (Asteraceae)
Medicinal Plants
• Plant/plant compounds used to treat/cure
disease/illnesses
• Long history of human-plant use for this
• Usually accidental discovery of value
• ¼ to ½ modern medicines derived from plants
• Herbalists use strong plant solutions;
homeopaths use very dilute solutions
• Most rainforest species will disappear before
we can determine their medicinal value
Yams: Dioscorea
• Family
Dioscoreaceae
• Produce
diosgenin,
precursor
compound for
birth control
pills
Foxgloves
• =Digitalis
(Scrophulariace
ae; snapdragon
family)
• Compound
named digitalis
• Stabilizes
arrythmia
• 1st use in 1790s
Poppies: Papaveraceae
• Carpel produces latex
(milky juice) that contains
opioids
• Domesticated by
Sumerians 3500BC
• China-Great Britain
fought several wars over
mandated poppy
production
Cinchona tree
• Produces quinine,
an anti-malarial
compound
• Native to South
America
• Member of
Rubiaceae, the
coffee family
Willows
• Salicaceae
• Bark/leaves
contain salicylic
acid, which, in
mammals,
converts to
acetylsalicylic
acid or aspirin
• Bayer patented
aspirin in 1899
Periwinkles
• Produce antitumor
compounds
vinblastine,
vincristine
• Apocynaceae
(dogbane
family)
Psychoactive plants
• Plant with compounds that affect mainly
the central nervous system
• Usually causes hallucinations,
delusions, visions, etc.
• Can be fatal
Coca
• Cocacocaine, an
alkaloid
• Bushes; tropical, midhigh altitude
• Member of
Erythroxylaceae
• Natives chew leaves
to prevent altitude
sickness
• Present in early
versions of Coca-cola
• Stimulant effect
How cocaine works:
• Normally: norepinephrine
(neurotransmitter) is released from axon
of one neuron & stimulates a nearby
neuron
• Cocaine prevents the reuptake
(recycling) of norepinephrine, so overstimulation occurs
Peyote
• Cactus
(Cactaceae)
• Used in Native
Am. Ceremonies
• Flower buds are
most potent
• Hallucinogenic
• Induces nausea
before ‘high’
• Compound is
THC
• Member of
hemp family
Cannabaceae
• Long-term use
produces brain
shrinkage
• Can be used to
alleviate
effects of
chemotherapy
or HIV
Marijuana
Opium/Heroin
• Heroinbrain
opiate receptors
dopamine
release=pleasure
• 4-5 hour ‘high’
• Pain is blocked
• Body adapts,
requires more &
more
Nicotine
• Tobacco in
Solanaceae
• Nicotine=alkaloid
• Also a dopamine
releaser
• Also addictive
LSD
• Lysergic acid
• 2 natural sources:
several morning
glory species & a
fungus (ergot)
• Morning-glories: ¼
seed can be fatal
• Ergot: Salem witch
trials?
Stimulating Beverages
• Usually served hot
• Usually have
caffeine or other
stimulant
• Several major:
coffee, chocolate,
tea, kola for
example
0mg
50mg
100mg
150mg
200mg
Green
Tea
Oolong
Tea
Black
Tea
Coffee
Amounts of caffeine per 5 ounces of beverage.
Tea
• Camellia sinensis
(camellia from China)
• Theaceae
• Shrubby; after Opium
Wars, Brits took tea to
India (now #1 grower)
• 2 types: green & black;
difference in how leaves
are harvested
• Green tea: leaves picked,
shredded, allowed to dry
• Black tea: leaves picked,
sometimes shredded,
wetted to allow
fermentation, then dried
Chocolate
• Theobroma cacao
(Sterculiaceae)
• =cocoa (not coca!)
• Central American tree
• Theobroma=food of the
gods
• Flowers arise from outer
cortex cells, not from
axillary buds
• Chocolate compounds
come from fermentation
of seed sheaths
Chocolate
• Stimulant in chocolate
is theobromine,
chemically almost
identical to caffeine
• Very bitter alkaloid
• Fermentation changes
to usable produce
• Labor-intensive
industry
• White chocolate has
no chocolate in it
Coffee
• Native to
Ethiopia (Africa)
• Exported by
Arabs to rest of
world for 1000
years
• Dipped seeds in
boiling water to
prevent others
from growing
Coffee
• Genus Coffea in
family Rubiaceae
• 3 species used:
– C. arabica ~90% of
world’s coffee
– C. canephora ~9%
– C. liberica ~1%
• Coffee ‘bean’ not a
true bean but 2
seeds per fruit
Coffee’s history
• 1720s: coffee seeds/plants stolen from
Paris botanical garden & transported to
Caribbean
• From several trees to thousands in a
few decades
• Then transported to Brazil, Colombia,
Venezuela
• Brazil now #1 grower
• Coffee more valuable than oil
Coffee processing
• ‘beans’ picked green
• Transported to
coasts; roasted on
site
• Bagged and shipped
to grocery stores
• Decaf coffee made
by steaming or
organic solvents
• Instant coffee
Alcoholic Beverages
• Alcohol=ethanol (not methanol;
methanol is poisonous)
• 2 types: fermented & distilled
• Alcohol derived from Arabic al kuhul
because they invented distillation
process
• Proof = double the % of ethanol:
– 100 proof = 50% ethanol
– 190 proof = 95% ethanol
Fermented vs. Distilled
• Fermented: beers,
wines
• Distilled: uses
fermented solutions &
steam to concentrate %
ethanol
• Fermented uses fungus
Saccharomyces to turn
glucose into ethanol as
a byproduct
• ~50% of sugars get
made into ethanol
Fermented: Beer
• Beers start as
fermented grains
• Usually barley, rye, or
wheat (sometimes
corn)
• Malting=sprouting
grain used
• Hops (marijuana
family) used to debitter beer
• Beers (by law) usually
3.5%-8%
Fermented: Wine
• Wines start as fruits (grapes usually),
not seeds
• Grape wine usually red or white; white
wine has skins removed; red keeps skins
• Usually 4-8% ethanol
Other fermented:
• Sake—rice beer, not
wine
• Pulque—agave-based
(yucca relative)
• Chicha—corn-based
Distillation Process
• Ethanol boils at
83C, water at
100C
• As ethanol
evaporates,
leaves water
behind
• Fumes are
concentrated
Distilled: Whiskeys
• 3 types: scotch,
bourbon, rye
• Scotch: malted barley
• Bourbon: malted corn
(only American
whiskey)
• Rye: malted rye
Distilled: Vodka
• Potatoes used as starch
source
• Usually 100-200 proof (50100%)
• Can almost run car on high
proof vodka
• Tasteless, odorless
Distilled: Rum
• Uses
sugar
cane sap
as sugar
source
Distilled: Gin
• Flavored with juniper
cones (‘berries’)
• Gin & tonic favorite
drink of British because
in India, gin covered
the bitter taste of
quinine (anti-malarial
drug)
Distilled: Tequila
• Made from sap
of yucca-relative
Brandy/Liqueurs
•A fortified wine
•Wine+ethanol
•Usually based on nongrape wine; ex.
Blackberry, elderberry
Textiles
• Early cultures used animal skins
• About 15,000 yrs ago (maybe as much
as 40,000) we see woven clothes
• Cloth ‘fiber’=cellulose, not a botanical
fiber
• Commonly derived from seed hairs
(cotton), stems (linens), or lignified leaf
fibers (“hard” ex. Agave)
Textile
Cotton
World Production by Textile
Nation
China, US
Flax (linens)
China, France
Hemp
China, Romania
(outlawed by the U.S.)
Jute
India
Sisal
Brazil
Cotton
• Gossypium sp. in family
Malvaceae
• Cotton ‘fibers’ derived from
single epidermal cells of
seed coat
• History: as British withdrew
after Rev. War, took sugar
supplies; U.S. needed fast
economic boost
• 1790s—Eli Whitney invents
cotton gin—begins period of
massive slavery
• 1791—400 bales produced;
1800-30,000 bales produced
Whitney’s cotton gin
Modern Cotton Gin
Flax
• Linum sp. in
Linaceae
• Stem tissues
provide strong
fabric=linen
• Superior to
cotton, but more
expensive to
make
Hemp
• Marijuana
family
(Cannabac
eae)
• Stem
tissues
provide
tough,
durable
fabric
Rayon
• Chemicallystraightened
cotton ‘fibers’
• Doesn’t
wrinkle as
easily
• Invented as a
cheap
alternative to
silk
Dyes
• Probably used
originally to dye skin
• Common dyes:
– Henna (brown)
– Indigo (blue)—color of
royalty before purple
was discovered
– Saffron (yellow)
– Nettles (green)
Genetically Modified Crops
• Non-plant genes
incorporated
• Ex. Golden rice—
has extra copies of
Vitamin A genes
• Ex. Bt corn
(Morningstar Corn)contain natural
insecticide genes
from Bacillus
thuringiensis
The downside:
• Unknown and unpredictable effects
• Ex. Bt corn genes have now shown up
in the ancient varieties still grown in
northern Mexico
• Ex. Monarchs may be damaged by
contact with pollen containing Bt genes
Descargar

Agriculture