Plant Science

Plant (and Animal) Domestication

domestication plants for around 10 thousand years

• people collected/planted seeds of wild plants with desired traits

1st Domesticated Plants

in Mesopotamia

Wheat, Barley, Lentils, Peas

Germination + Emergence

Have a higher rate in domesticated pants

the forming of a radical (main root) under the soil → emerging above the soil + growth

Modern Plants are…

bred to have a greater rate of germination and reduced seed dormancy (optimize yield)

benefits: increased food production/trading, stability of economy, create time for many, advancements of tool production

Recently domesticated plants

wild rice, sunflowers, sugar beets

Sunflowers (wild vs. domestic)

wild: more branching, better for pollinators (increased biodiversity), always flowering ~ food source for longer time for pollinators

domestic: ombre than crossed, 1 main stock/flower

Native Plants + Biodiversity

plants greatest biodiversity is at sight of origin (native)

Native too…

• North America: blueberry

• Africa: watermelon

• China: soybeans

• India: cucumbers

hard to grow plants in their place of origin

Germplasm

preservation + maintenance of plant genetic material

Shattering

seed pod breaking to spread seed

Drought Stress + Plant Growth

Africa has the highest rate of population growth and the greatest amount of water scarcity

How do Plant Scientist Solve Modern Problems?

1. create drought tolerant crops

   1. plants with larger biomass (large roots) deeper into soil, drought tolerant crops (sorghum)

2. require less water/fertilizer

   1. legume family → nitrogen from air (N₂) put into soil as NH₃ ~ soybeans, beans/peas, alfalfa

3. crops more resistant to pathogens

   1. breeding new genes to aid in disease resistance

4. crops more nutritious

   1. prevent VAD, anemia, hunger

      1. biofortified food: golden rice, iron rich rice, antioxidant enriched tomatoes

We Need Plants to Live

provide oxygen we breath, provide most of chemically stored energy we consume

produce chemicals: vitamin A, caffeine

many 1st discoveries were described in plants → cells, viruses

Plants and Starvation

only 20 plants that stand between humans and large-scale global starvation

Plant Characteristics

• produce own food + have a cell wall

have the ability to change with time

• population: interbreeding group of organisms that share a gene pool

• evolution (accumulated change):

  • natural: dependent on pollinators and species

  • artificial: Brassica oleracea ~ made kale, brussel sprouts, broccoli, cabbage → all man-made from one plant by artificial selection

Taxonomic Hierarchy

Corn: Zea mays → Zea (genus, always capitalized) ~ mays (species, always lowercase)

underlined or italicized

Classification - Common Name

simple and easy to remember, descriptive of plant

• scientific name: universal, descriptive, latin/greek

Classification - Family

similar shared characteristics ~ Fabaceae family (legumes) → put nitrogen into ground

Variety vs. Cultivar

Variety → var. after scientific name = plant variety

• subspecies/naturally occurring variety

Cultivar → cv. after scientific name = subspecies

interchangeable

Classification: Annual

completes life cycle in 1 year

spring vs winter

• winter wheat