Lecture 9 Flashcards
what is a reporter gene
attaches to the regulatory sequence of of another gene of interest in bacteria, animals or plants
Why is GM advantageous for plant breeding
can move genes between species without any restriction
What are the types of plant breeding methods
artificial selection
vegetative propagation
marker assisted breeding
What is artificial selection
The breeding of selected organisms to produce strains with desired traits
what is the advantage of hybridization
used by breeders to introduce new genes
Where did modern maize originate
product of artificial selection
- Teosinte
Where was corn first domesticated
central America
What are the advantages of the modern corn
larger cob
larger kernel size
permanent attachment of seeds to cob
encasement of entire cob by tough husk
What plants were derived from the wild mustard
cabbage Brussels sprouts kale broccoli kohlrabi
What was the cabbage selected for
selection for apical bud
What was the broccoli selected for
selected for the flowers and stems
What was the kohlrabi selected for
selection for the stems
What was the kale selected for
selection for leaves
What was the Brussels sprouts selected for
selection for axillary buds
Who is Norman Borlaug
Nobel Prize winner 1970 and father of the green revolution
- researched GA genes
What initiated the green revolution of the 20th century
increased use of fertilizer
introduction of semidwarf (GA mutants) varieties of grains
What were the advantages of the semi dwarf varieties
put more energy into seed production than stem growth
are sturdier; less likely to fall over
What is marker assisted breeding
- use DNA makers linked to desired traits to aid selection of individual plants in breeding program
eg. Red-fleshed apple trait is associated with a particular PCR band
What makes the red fleshed apple different from the white fleshed apple
red fleshed variety has a larger promoter region than white fleshed variety
- larger PCR band always present in red fleshed varieties
- amplification of MYB10 promoter region; used in breeding program to select plants at the seedling stage; more space in the orchard as other plants can be discarded
What is vegetative propagation
is the asexual propagation of plant through tissue culture, cuttings and/or grafting. It allows for propagation of clones (genetically identical) of superior varieties of plants, or of plants that are sterile.
- test tube cloning and plant tissue culture (orchids and calla lilies)
What are common examples of plants propagated vegetatively from cuttings
- most house plants
- woody ornamentals
- orchard trees
eg. kiwifruit and apple orchards are made up of identical vines/ trees
What type of culture is the best approach to ensure no mutation will occur
meristem culture
mutant free propagation
true or false; plants arising from organogenesis ad embryogenesis have high frequency of mutations termed somaclonal variation
true
What do you call the mutations that arise from organogenesis and embryogenesis
somaclonal variation
What are the typical applications of plant tissue culture
- propagation of superior cultivars by meristem culture eg. orchids
- pathogen removal from plants by meristem culture eg. virus free potato plants
- embryo rescue to generate new hybrid plants
eg. sweetpeas - production of secondary metabolites in suspension cultures
eg. ginseng
Define genetic engineering
regeneration of transgenic plants carrying introduced transgenes
What properties of future GM cassava
- increased protein, iron, b-carotene
- bigger roots
- reduce cyanide producing chemicals in roots
What are ‘smart’ plants
- inform the grower of nutrient deficiencies before damage has occurred
- a blue tinge indicates when these plants need phosphate containing fertilizer
What is golden rice
- a transgenic variety being developed to address vitamin A deficiencies among the worlds’ poor
Describe the short history of transgenic plants; 1984, 1984, 1994, 1995
1984: first transgenic tobacco plants obtained
1984: roundup resistant petunia plants produced- first commercial phenotype
1994: FlavR SavR tomato cleared for commercial release
1995: roundup ready soybeans released; first successful commercial GM crop
What is roundup
a herbicide
that kills weeds (unwanted plants)
What are pesticides
kills animals
what are herbicides
kills plants
What kind of transgenic crops have been developed
- produce proteins to defend them against insect pests
- tolerate herbicides
- resist specific diseases
Give an example of a pest resistant crop and what made it resistant
insect resistance with BT gene
- used commercially in corn and cotton to give insect resistance
What are round up ready soybeans
- round up is a non selective herbicide
- kills weeds
- round up ready gene expressed constitutively in plants (soybeans, canola) to protect them from the herbicide
What is procedure of marker assisted breeding in apples
- ) extract genomic DNA from apple plants
- ) carry out PCR
- ) run gel and visualize DNA bands
- ) score for the presence or absence of the band
- ) identify which seedlings carry out the band associated with red fleshed apple trait
What is harvest index
proportion of plant that is harvested for consumption
eg.
- cereals, increased size and number
- dwarfing to decrease leaf number and lodging etc..
true or false; most crop improvement has been derived from selecting plants with an increased harvest index
true
What is embryo rescue
to generate new hybrids- culture of embryos after fertilization allows survival of hybrids that do not develop into seeds naturally
