Crop Evolution Flashcards
What are characteristics of domesticated plants?
- High carbohydrate (or oil)
- Useful traits such as seed retention, good size
What are the 3 stages of domestication?
- Food procurement from wild plants
- Food production from wild plants dominant
- Crop productions dominant
What is a characteristic of wild plant populations?
- genetically diverse
What is an ecotype:
A subpopulation of wild plants sharing a gene
What generally lowers diversity of wild plant populations?
Adaptions to local environment.
What generally increases diversity of wild plant populations?
Requirement to respond to altering condititons.
Why were crops domesticated?
- Reliable food supply
- Conditions can be controlled for greater yield
-Beneficial traits can be selected
What is inbred cultivar?
Continuous selection from one plant
Compare original variety potatoes with European potatoes:
Original:
- Diploid - low yield
- Flowers on short days
- Toxic
European:
- Triploid - high yield
- Flowers on long days
- Not toxic
What has happened to the sugar content of sugar beet?
Sugar content has increase because of selection. It was used as an alternative to sugar cane in the 1800s.
The limit was reached as genetic diversity had been exhausted
How does stem strength/length limit yield?
Lodging can occur: when the stem is not strong enough so the plant falls over.
What do dwarfing genes do?
Make plants shorter and stouter.
Increases yield as less fall over and biomass can be used for grains instead of height.
What is the green revolution?
Large public investments into plant breeding led to the intensification of agriculture.
What did the IRRI do (International rice research institute)?
Introduced dwarfing genes into rice (IR8 line), increased yield. 11 tonnes/Ha per 150 kg/Ha of Nitrogen.
What are negatives of staple crops?
- Input intensive
- Susceptible to climate change
- Poor nutrition
