Triticum spp (Poaceae)

• domesticated 10-11,000 YA
• used by humans for 20,000+ years
• cultivars names based on: 

-Grain color (red, white, amber)

- Growing season (winter wheat needs cold period to flower, spring wheat flowers asap)

-High protein content (hard wheat)

-High starch content (soft wheat)

• Hybridization and polyploidy
• Einkorn wheat (T. monococcum)

-diploid (14 chromosomes)

- 1st cultivated

-wild forms still founds

• Einkorn wheat x goat grass -> Emmer wheat (T. turgidum)

-tetraploid (28 chromosomes)

-natural polyploidy

-cultivated einkron and emmer wheat in same area

-not widely used now

-naked grains -> durum wheat (used for pasta)

• Emmer wheat x goat grass -> Bread wheat (T. aestivum)

-AKA common wheat (most cultivated wheat in the world)

-Hexaploid (42 chromosomes)

-spelt wheat also had same history and likely appeared before bread wheat, but is less popular today

Have Hull (Hulled)

• need to remove hulls/husks
• wild wheat
• domesticated wheat (einkorn, emmer, spelt)

Free-Threshing

• naked grains separate upon threshing
• durum wheat
• bread wheat (aka common wheat)

• Needs gluten

-proteins (gliadin, glutenin)

-celiac disease = no gluten

-wheat and rye have enough gluten for leavened bread

• first made 4,000 YA in Egypt with wheat flour
• flour  + water + yeast (or baking soda/powder) = leavened bread
• previously added heat to grains before threshing

-heat changed gluten -> lost elasticity and CO2 not trapped inside

• refined flour -> primarily endosperm -> less nutritious but spoils slower 

Eragrostis tef (Poaceae)

• grows best at mid-altitudes
• its gluten doesn't have gliadin (protein that impacts people with celiac disease)
• teff flour + water fermendted and baked  = injera (Ethipian bread)

• higher protein = heavy, crusty bread
• lower protein = softer, lighter
• whole wheat: shorter shelf life; added to white flour
• bleached (refined): use various chemicals to oxidize the flour -> rises better, fluffier
• self-rising: white flower mixed with leavening agents that help gluten production

• Zea mays (Poaceae)
• domesticated 7-9,000 YA in Mexico
• spread throughout Americas
• wild ancestor still debated, but most say it's teosinte (fewer kernals, multiple stalks, hard casing)
• used for food, feed, biofuel, bioproducts

• 20% consumed directly by people
• 40% for animal feed
• 40% for ethanol
• more corn for biofuel than livestock (or any other use) Aug 2010-2011 

• each is style and stigma of individual carpellate flower
• medicinal uses: urinary tract infections, stopping bed-wetting, diuretic, inflammation of the bladder, reducing swelling associated with gout and PMS, high blood pressure

• lost of genotypic and phenotyipic variation
• each kernel = different fenotype (1 ear = population)
• jumping genes: movable genetic elements: transposons

-chromosome fragments move from one position to another on a chromosome

-transposon inserts onto chromosome -> alters expression of near genes

-transposons cause insertions, deletions, translocations

-85% of corn genome consists of transposons

• sequenced in 2009
• 32,000+ genes
• some genes not found in other organisms
• high allelic variation at QTLs (Quantitative Trait Loci: sections of DNA associated with genes that are for phenotypes determined by two or mmore genes), and impacted by environment

• differ in endosperm starch (hard starch = more amylose, soft starch = more amylopectin)
• popcorn
• flint
• flour
• dent
• sweet
• waxy
• pod
• color varieties based on pigmentation of endosperm, aleurone, and pericarp

• oldest and most primitive made 5,600 YA
• heat -> kernels swell and burst
• kernels are hard

- hard starch surrounds soft starch

-cells in endosperm center have water and oil

-water heats up -> steam -> pressure increases

-starch gelatenizes and softens

-kernel explodes -> inside-out

-endosperm starch and proteins expand due to change in pressure

• aka field corn
• type of corn primarily grown in the US: animal feed, corn starch (from endosperm), corn meal (flour), corn oil (germ), corn syrup, bioproducts (plastics, biofuel)
• hard starch = sides of kernel
• soft starch = top and center of kernel
• when dried soft starch shrinks -> dent in kernel
• higher in starch and lower in sugar than sweet corn

• corn -> milled -> dextrose extracted from starch -> fermentation of dextrose -> lactic acid -> convert to lactide by heating lactic acid with catalyst -> link together to form polyplactic acid (PLA) -> white pellets
• less reliance on oil than traditional plastic production
• less waste

• higher sugar content than dent corn and popcorn in endosperm
• natural variety due to mutation
• genes controlling sugar content have been identified -> selective breeding

• purpose: to increase production
• almost all corn in US is a hybrid
• characteristics: 2-3 ears/stalk instead of 1/stalk, easier for mechanical harvesting (stronger stalks, ears in same location)
• cross inbred lines (w/ desired traits)
• hybrid seeds = male-sterile lines

• rats fed HT maize had more tumors
• controversial
• problems with research?

• Oryza spp. (Poaceae)
• second-highest crop production
• Asian rice (O. sativa) domesticated 8-10,000 YA; most common today
• African rice (O. glaberrima) domesticated 2-3,000 YA; now more Asian rice than African rice grown in Africa
• monocot
• many varieties

• in all types we consume the endosperm
• brown rice = husk (hull, chaff) removed
• white rice = husk, bran, and germ removed
• enriched rice = add back thiamine, iron, niacin, folic acid (in US white rice MUST be enriched with iron, B1, B3)
• instant rice: rice that's been cooked and dehydrated (rehydrate to prepare)
• Parboiled rice: PARtially boiled; husk stays on while boiling - easier to remove bran by hand; retains some nutrients after removing husk and bran; shorter cooking time because already boiled
• Puffed rice: rice is heated with added steam (kernels tend to have low moisture); sometimes heat rice under pressure, then suddenly release pressure -> rice puffs

• most rice is lowland: grown in paddies (flooded fields) that are drained for harvesting (harvesting and seeding done by machine in US, by hand in developing countries)
• some rice is upland: grown without flooding
• aquatic fern Azolla spp. once considered weed, but now encouraged because of its symbiotic nitrogen-fixing Anabaena azollae (cynobacterium)

-green manure used for centuries

-also fed to livestock

• Hordeum vulgare (Poaceae)
• domesticated 10,000 YA in Middle East
• wild relative (H. vulgare) still found today in natural and disturbed habitats
• not gluten-free
• brought to US in 1602: food and beer
• today: animal feed and beer

• Pennisetum glaucum (Poaceae)
• Most common type of millet
• originally from Africa
• Domesticated 4-5,000 YA
• grows better than most other cereal crops in areas that are: high temp/salinity/acidity, low moisture/nutrients
• in US primarily used for birdseed and forage

• parts used: stalks (canes) pressed for juice, seeds are food grain in Africa/Asia, entire plant fed to livestock
• juice boiled down to make a syrup (can be fermented to make ethanol)
• hardy grass - looks like corn stalk, but can grow up to 13 ft
• hardy - fast growing and can live in variety of soils

• Sorgum bicolor (Poaceae)
• Native to Africa
• Annual (some cultivars are perennials)
• Food for humans (usually not in North America, but popularity increasing b/c gluten free), animal feed, forage, biofuel
• genome sequenced in 2009
• drought-tolerant

• high-sugar variety
• does better than other crops under dry, warm conditions
• grown on variety of soils
• brown midrib (bmr) mutants: lower lignin in stems and leaces -> less energy needed to convert into ethanol

• Saccharum spp. (poaceae)
• native to Asia, used for at least 8,000 yrs
• most commercial varieties are hybrids
• used for food, drink, ethanol
• Brazil is greatest producer

• Panicum virgatum (Poaceae)
• native to North America
• perennial
• uses: pasure, hay, erosion control, phytoremediation, fuel, pellets to replace coal, ethanol
• rapid growth and high biomass make good candidate for biofuel (energy for growth < energy yielded)

• Miscanthus giganteus (Poaceae)
• hybrid of M. sinensis and M. sacchariflorus
• native to japan
• perennial
• used for heat, electricity, biofuel in EU
• low water requirements
• can grow in poor soils
• sterile
• did better than both corn and switchgrass in biofuel research

• Arachis hypogaea (Fabaceae)
• native to South America
• Aspergillus flavus mold produces aflatoxin (carinogen) - USDA destroys loads with mold, requires peanuts to be processed at high heat

• stems grow from the flowers after fertilization na force their wat into the soil resulting in the fruit being found below ground

• Medicago sativa (Fabaceae)
• Native to Middle East
• perennial
• tetraploid
• most cultivated forage legume worldwide
• Allelopathy: autotoxicity (competition within a species)
• crop rotation necessary
• high in fiber, calcium, vitamins B/C/E
• high in protein b/c N-fixing bacteria
• high in phytoestrogens:isoflavones

• Fabaceae family
• Nitrogen fixatoin due to mutualistic relationship between roots and bacteria
• legumes + grains -> essential amino acids
• crops: alfalfa, soy, clover, peanuts, beans, peas, lentils