Angiosperm reproduction Flashcards
(14 cards)
What is a disadvantage to asexual plant reproduction?
Lack of genetic diversity places asexually produced plants at risk (no variation introduced as in sexual reproduction)
What are some advantages of asexual plant reproduction?
- Removes requirement for pollination
- All genetic material is passed on to offspring
- Can be beneficial to plant success in a stable environment
- Vegetative plants are more likely to survive than seeds
What are some mechanisms that make it difficult/impossible for self-fertilisation in plants?
- Lack of carpels
- Lack of stamens
- Functional carpels and stamens that
mature at different times or are arranged to make it unlikely for self fertilisation - Self-incompatibility
What is self-incompatibility?
A biochemical block which prevents pollen from fertilising the egg of a flower of the same plant
What are the main methods of asexual reproduction?
- Fragmentation
- Apomixis
- Vegetative reproduction
What is the purpose of self-incompatibility?
To promote genetic diversity
Vegetative Reproduction techniques include:
- Cuttings from plant fragments
- Grafting (scion onto rootstock)
- Tissue culture
How do people modify crops?
By breeding and genetic engineering
What is the “trade off” with asexual reproduction?
It ensures genetic consistency and doesn’t require pollinators, but lacks genetic diversity.
What are the basic steps to plant breeding?
- Select parents with traits of interest
- Cross parents to produce progeny
- Produce multiple generations of progeny
- Field test progeny over multiple locations and years and select best lines
- Release variety
What does GMO mean?
Genetically modified organism
What traits in crops have humans selected for?
- Reduced seed shattering
- Loss of dormancy requirements
- Reduced height
What are some example of new breeding technologies?
- High-throughput genotyping and phenotyping
- Gene editing (targeted DNA changes)
- Speed breeding (accelerated generation cycles)
- Genetic modification (GMOs with novel gene arrangements)
Why must plant breeding increase yields?
To meet food demands while addressing climate change impacts and emerging pests/diseases
