W5 Botany - Root Morphology Flashcards
What are the primary functions of roots?
- Absorption and transport of water with dissolved nutrients
- Anchorage of the plant in soil
- Storage of sugars manufactured in leaves
- Formation of symbiotic relationships with soil microbes
- Interaction with roots of adjacent plants
What is a fibrous root system characteristic of?
Monocotyledons
List the characteristics of a fibrous root system.
- Produces roots of equal diameter from the seed
- Roots branch only once or twice
- New roots continually grow from the plant base/crown while old roots die
- Roots don’t become thicker or woody
- Typically lives around 3 years
What plants typically exhibit a fibrous root system?
- Grasses
- Palms
- Most monocots
What characterizes a tap root system?
- Characteristic of dicotyledons and conifers
- Produces one primary (tap) root from the seed
- Lateral roots branch from the tap root
- Usually wider than deep
What happens to tap roots over time?
They can become thicker and woody
What are common examples of plants with a tap root system?
- Most trees
- Shrubs
What is unique about an adventitious root system?
- Does not grow from a seed
- Grows from other plant parts, typically stems
How do adventitious roots assist in propagation?
- Important for vegetative/asexual propagation (cuttings, division, layering)
What is the role of the root tip?
- Most important part for water and nutrient absorption
- Has root hairs that increase surface area for absorption
What is the rhizosphere?
A narrow zone (about 5mm) of intense biological and chemical activity around roots
What can cause sudden plant death related to roots?
- Kinked and girdling roots
What are signs of oxygen deprivation in roots?
- Poor growth
- Wilting despite moisture
Fill in the blank: Roots need oxygen for _______.
respiration
What is root pruning used for?
- Stimulating growth of new lateral roots
- Keeping rootball small and densely branched
What is the purpose of cuttings in propagation?
To develop adventitious root systems
What is layering in plant propagation?
Occurs when stems produce adventitious roots while still attached to the parent plant
What are root suckers?
New stems growing from roots
True or False: Root suckers grow from epicormic buds at the stem base.
False
What is grafting?
Joins a length of stem (scion) with several nodes to a new set of roots (rootstock)
What is budding?
Joins only an axillary bud to the rootstock
What is a major consideration when grafting?
Plants must be closely related and compatible
What can viruses and toxins do in grafting?
Spread between parts
