plant growth and development part i - msu...
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Plant Growth and Development Part I
Whole Plant
Organs
Macromolecules
Organelles
Tissues
Cells
Levels of Organization
Whole Plant
Organs
Macromolecules
Organelles
Tissues
Cells
Levels of Organization
Plant Cells
Differentiation in Cells➢ Refers to the process by which distinct
plant cells arise from precursor cells and become different than each other
➢ Unique adaptation of plants
Whole Plant
Organs
Macromolecules
Organelles
Tissues
Cells
Levels of Organization
Plant Tissues – Xylem and Phloem
= xylem•Transports water and minerals
from the roots to the plant parts
•Moves only in one direction
= phloem•Moves photosynthates (sugars)
throughout the plant
•Moves both directions
These internal tissues are also important for
supporting the plant….
http://www.fairchildgarden.org/EduProfDev/Leaf_anatomy.html
Movement of water through the plant: Transpiration
Heat
Stomata – microscopic openings, usually
on the bottom of a leaf, important for gas
exchange and transpiration
Vascular cambium
Vascular cambium
•Located between the xylem
and phloem
•Produces new xylem and
phloem tissue
•Responsible for increasing
stem diameter.
Phloem, Xylem and the Cambium Layer
Knowing the cambium layer is important when looking at wood boring insects
and disease – such as mountain pine beetle
Knowing the Cambium Layer is Important for Plant Grafting
Or, why leaving trees tied for too long or
Why letting the 13-year-old weed whip around trees
Is a bad thing…
XYLEM
PHLOEM
VASCULAR BUNDLE
http://www.fairchildgarden.org/EduProfDev/Leaf_anatomy.html
CAMBIUM
PITH
EPIDERMIS
Vascular Bundle Arrangement
Un
der
stan
din
g C
rop P
roduct
ion, S
tosk
opf.
, 1981
Monocot (grass) Dicot (broadleaf)
Whole Plant
Organs
Macromolecules
Organelles
Tissues
Cells
Levels of organization
Vegetative Organs (plant parts)
➢Stem➢Leaf➢Root➢Shoot➢Bud
Asexual (vegetative)
Reproduction
The Function of Stems
➢Mechanical support and display
➢Movement of water and minerals up to the leaves
➢Movement of photosynthates (sugars) to other parts of the plants
➢Asexual propagation
➢Storage
http://www.gimcracker.com/blab/archives/2002_12.html
Modified Stems
➢ Crown
➢ Stolon
➢ Rhizome
➢ Corm
➢ Bulb
➢ Tuber
➢ Spur
Can grow above
and below ground
Woody Stems
➢Shoot
➢Soft young stem with leaves
➢Twig
➢Dormant stem one year old
➢Branch
➢Stem over one year old
➢Trunk
➢Main stem of a woody plant
21
The Parts of a Woody Stem
Parts of a Plant Shoot
➢Leaf primordia
➢Shoot apex
➢The tip of the shoot
➢Axillary bud
Parts of a Plant Shoot
➢Node
➢Area on the stem where a leaf, another stem, or flower bud is located
➢Internode
➢Space between the nodes on a stem
Vegetative Buds➢A bud is an undeveloped
shoot that produces leaves and/or flower parts
Determining One Year’s Growth
A Plant’s Life Cycle – Annuals
➢Annuals
➢Completes life cycle in 1 year
➢Grow, mature, bloom, produce seed and die
➢ Summer annuals complete their life cycle in spring and summer
➢Winter annuals complete their life cycle during the fall and winter.
Usually easy to pull
out of the ground
Summer Annual Weeds
➢Black medic
➢Pigweed
➢Pineapple weed
➢Purslane
Winter Annual Weeds
➢Chickweed
➢Henbit
➢Penny cress
A Plant’s Life Cycle – Biennials
➢ Biennials➢Requires all or part of 2
years to complete its life cycle
➢Vegetative 1st year
➢Overwinters
➢ Flowers and fruits 2nd year
➢Bolting (flowering in one year) may occur in extreme environmental conditions
A Plant’s Life Cycle – Perennials
➢Perennials➢Live for many years
➢Woody➢Trees and shrubs
➢Herbaceous➢Die back to the ground
in Montana
What are the issues
with reading about
herbaceous perennials
on the Internet or in
popular publications?
How about leaves?
Dartmouth.edu
The inside
story
http://www.fairchildgarden.org/EduProfDev/Leaf_anatomy.html
Functions of Leaves
➢Food manufacture – photosynthesis
Functions of Leaves
➢Protection of delicate tissues like buds
➢Bud scales
➢Floral bracts
➢Sepals
➢Storage – Cotyledons, bulbs
Plant Identification Key
Blade (lamina)
Apex
Vein
Margin
Base
Petiole
Leaf
Structure
Types of Leaves – Venation
Monocot (grass) Dicot (broadleaf)
Types of Leaves – Simple Leaves
Types of Leaves – Compound Leaves
Opposite Whorled Alternate
Leaf Arrangement
Leaf Shapes and Margins
Plant Identification Key
Roots
➢Anchorage➢Nutrient and water absorption➢Storage➢Aerial support➢Propagation (sometimes)
➢Roots that are not growing cannot absorb nutrients
Cross Section of a Root➢ Root cap
➢ Protection
➢ Apical meristem region➢ Cell division
➢ Elongation➢ Pushes root through soil
➢ Differentiation➢ Root hairs and secondary
roots
➢ Root hairs➢ Absorb water and
nutrients
Roots
Modified Roots➢Swollen root
➢Prop roots
➢Radicle
Reproductive Organs
➢Flowers
➢Fruits
➢Flower buds
➢Seeds
Sexual Reproduction
Parts of a Flower➢Sepal
➢Usually green; protect the flower
when it is in bud
➢Petal➢Attract pollinators
➢Pistil ♀
➢Stigma➢Pollen falls and develops
➢Style➢Stalklike part between the stigma
and ovary
➢Ovary➢Enlarged part of the Pistil that
containing ovules
➢Stamen ♂
➢Anther ➢The part of the stamen that
contains the pollen
➢Filament➢Stalk of the stamen
Parts of a Flower
♀ - Pistil
Stigma
Style
♂ - Stamen
Anther
Filament
How about flowers . . .
♂ ♀
“My squash is putting out a lot of
flowers, but I am not getting any fruit…”
How about flowers . . .
♂ ♀
How about flowers . . .
➢Not all flowers have both male and female parts
➢Some plants may contain only male or female flowers
➢We will discuss this more in following classes
♀
♂
Composite Flowers
Inflorescence (Flower) Types
Plant Identification Key
Questions?