Ag Science - Applied plant genetics

What does genetic improvement involve ?

Change in a plant or animal that involves a benefit to the plant or animal, the farmer, community or the environment

What does applied genetics involve ?

The manipulation of hereditary characteristics in order to improve or produce desirable characteristics in offspring

What are the desirable characteristics ?

fertility, increased milk production, better growth rates in breeds of cattle or higher and better yields in disease resistant plants

What does heritable mean ?

Describes characteristics that are genetically transferred from parent to offspring

What theory did Charles Darwin propose ?

The theory of biological evolution by natural selection

What does natural selection favour ?

Traits that are beneficial

It acts on existing variations within heritable traits

What are the key observations made by Darwin ?

Traits are heritable: passed from parent to offspring

More offspring are produced than survive: more offspring than the environment can support. Competition for limited resources such as food, habitat, mating

What were the conclusions based on Darwin’s observations ?

Not all individuals will survive or reproduce; they must compete for resources as the environment cannot support them all

Individuals that gave traits that allow them to adapt to the conditions of their environment will survive and reproduce. Favourable traits are passed to the next generation

What is progeny testing ?

The comparison of an animal’s or plant’s offspring with another animal’s or plant’s offspring kept under the same conditions

What is one method of progeny testing ?

Ear to row method

What is the ear to row method used for ?

The selection of maize plants for seed production

How does the ear to row method work ?

Fifty to one hundred plants are selected based on their phenotype. They are allowed to open pollinate

The seed from each plant are harvested separately

A single row of plants is grown from each selected plant. Each row is called a progeny row

How does the ear to row method work ? (2)

The rows are evaluated for desirable characteristics and superior plants are identified based on their phenotypes

The selected plants are allowed to open pollinate

Small progeny rows are grown again from the seeds and selected plants

What is open pollination ?

Pollination that takes place between two plants of the same species, or by self-pollination. It also means pollination that takes place naturally by wind, insect or water

What is performance testing ?

Comparing two animals or plants kept under the same conditions, such as housing and feeding for animals or crops grown in trials in fields under the same conditions

What is the DAFM ?

The department of agriculture, food and the marine

What does the DAFM produce ?

Recommended lists of varieties of crops that have been performance tested

What are the seed varieties for crops in 5 different areas that the DAFM produces ?

Cereals (wheat, oats, barley)

Herbage (grasses and clover)

Forage maize

Spring beans

Winter oilseed

What are the physical traits assessed for cereals ?

Straw height, resistance to lodging, straw breakdown, earliness of ripening, disease resistance

Grain quality:

What are the physical traits assessed for herbage ?

Grass: Heading date, total yield, ground cover, spring growth, silage yield, dry matter digestibility

Clover: total yield, leaf size, clover %

What are the physical traits assessed for forage maize ?

Dry matter yield, dry matter content, starch content

What are the physical traits assessed for spring beans ?

Yield, % crude protein, disease resistance, plant height

What are the physical traits assessed for winter oilseed ?

Relative seed yield, oil content, glucosilonate content, early vigour, full plant height, lodging resistance, full stem stiffness, earliness of flowering, earliness of maturity, shedding resistance, light leaf spot resitance