Wheat Flashcards
(24 cards)
What 9 crops provide 50% or the worlds calories?
Wheat, rice, maize, potatoes, cassava, soybeans, sugar beet, sugar cane, oil palm
What protein makes up the majority of wheat?
Gluten proteins (about 85%)
What makes up flour?
Raw wheat berries
What makes up semolina?
Hard durum wheat
How do you make malt?
Germinated wheat berries are dried
Who is Thomas Campbell?
“King of wheat” who created the tractors tillers in the 1920’s
In wheat anatomy what are the tillers
The stem
In wheat anatomy what is the spike
The part of the stem that holds the floral part
What makes up the spike of the wheat?
Spikelets that have multiple florets. Each floret is surrounded by two bracts: a palea on the inside and a lemma on the outside. The lemma often has the awn, a long hair like strand extending from it.
What surrounds the spikelet of the wheat?
Two bracts called glumes, collectively referred to as the hull or chaff when removed
Define vernalization
When a seed requires a cold period in order to germinate
What was the first wheat species to be cultivated?
Einkorn wheat- diploid with 14 chromosomes
What was the result of a random hybridization of einkorn and goat grass?
Emmer wheat- tetraploid (4n) with 28 chromosomes
Why was Durum wheat bred?
4n 28 chromosomes bred to be softer and have more protein
How many chromosomes does common wheat have?
42 chromosomes (6n) makes up 95% of the 700 million tons of wheat grown world wide
Define lodging
When fertilizers make the stalk of the wheat grow too fast and it can’t hold the berries and it droops
Who is Norman Borlaug
In 1940 went to Mexico to help breed a rust resistant wheat crop
Why is cross breeding wheat difficult?
Because it self fertilizes
What happens when humans domesticate a crop?
A domestication bottleneck that produces landraces
Qualities of a landrace
High genetic diversity
Adaptations to local climate, including stress
Openly pollinated
Low yields that are more variable
What happens when humans take a crop and start collectively breeding it for certain traits?
Modernization bottleneck and it becomes a cultivar
List the traits of a cultivar
Low genetic variation
High uniformity and specific traits
Specific farming requirements
Usually high yields
What role does colchicine play in plant breeding?
Used to produce polyploidy because it disrupts the mitotic spindle during meiosis
Who is trying to breed perennial wheat?
Wes Jackson
