Transcript NMHS Horticulture I

PLANT PHYSIOLOGY
Essential Standard 3.00: Summarize
Plant Anatomy
OBJECTIVE 3.01
• Discuss biological terms used to describe plants.
PLANT SCIENCES
• Biology-the branch of science that deals with both
plant and animal organisms and life processes
• Zoology-the part of biology that deals with
animals
• Botany the part of biology that deals with plants
PLANT SCIENCES
• Applied plant sciences are based on the purposes
for which the plants are grown
• Agronomy-The science and practice of
growing field crops such as cotton, wheat,
tobacco, corn and soybeans.
• Forestry-The science and practice of growing,
managing and harvesting trees for building
materials and other products.
• Horticulture-The science and practice of
growing, processing and marketing fruits,
vegetables, and ornamental plants
LIFE CYCLES OF PLANTS
• Annual-a plant that completes its life cycle in
one year
• Biennial-a plant that completes its life cycle in
two years
• Perennial-a plant that lives more than two years
LEAF RETENTION
• Deciduous-loses leaves during the dormant season
• Evergreen-keeps leaves and remains green yearround
MOISTURE IN PLANTS
• Turgid-plant is swollen or filled with moisture
• Wilted-plant is limp because it does not have
enough moisture
PLANT GROWTH
• Dormant
• A plant rest or grows very little
• Response to an adverse condition
SEASON CROP TYPE
• Cool Season
• Plants relish cool weather
• Pansies grow best in spring or fall
• Warm Season
• Grow best in summer and early fall
• Zinnia
• Marigold
• Vinca
• Poinsettia
OBJECTIVE 3.02
• Discuss the anatomy and
functions of plants.
LEAVES-EXTERNAL
• Petiole-leaf stalk or part that connects the
leaf to the stem
• Blade-the large, flat part of the leaf
• Midrib-the large center vein
• Veins-the structural framework of the leaf
• Margin-the edge of the leaf
• Apex – Leaf Tip
LEAVES-EXTERNAL
LEAVES-INTERNAL
• Upper and lower epidermis-skin of the leaf that
prevents the loss of too much moisture
• Stomates-small openings under the leaf for
breathing or transpiration
• Guard Cells-open and close stomates
LEAVES-INTERNAL
• Chloroplasts-small green particles that contain
chlorophyll
• gives leaves their green color
• necessary for photosynthesis
LEAVES-INTERNAL
LEAVES-INTERNAL
LEAVE-ADDITIONS
• Sessile describes leaves without a petiole
• Example zinnia
• Bracts are modified leaves
• Example poinsettia
• Needles and scales are modified leaves
• Example pine tree
LEAVE-ADDITIONS
• Glabrous leaves or stems have a smooth non-hairy
feel
• Example southern magnolia
• Pubescent leaves or stems have a hairy feel
• Example African violet
LEAVE-FUNCTIONS
• Respiration
• converts sugars and starches into energy
• Transpiration
• release of water vapor from the leaves of plants
• It also cools the plant
FUNCTIONS OF LEAVES
• Photosynthesis-manufactures food in green plants
which is the beginning of the food chain for all living
things
• Photosynthesis is the process by which carbon
dioxide and water in the presence of light are
converted to sugar and oxygen
• Video
STEMS-EXTERNAL
• Lenticels-breathing pores
• Bud scale scars-show where terminal buds have
been located
• Leaf Scars-show where leaves were attached
• Terminal bud-bud on the end of a stem
• Axillary or lateral bud-bud on side of stem
STEMS-INTERNAL
• Xylem-tissue that
transports water
and nutrients up
from the roots to
stems and leaves
• Phloem-tissue that
transports food
down from leaves
to roots
Phloem
Phloem
Xylem
STEMS-INTERNAL
• Cambium-thin, green, actively growing tissue
located between bark and wood and produces all
new stem cells
• Bark-old inactive phloem
• Heartwood-old inactive xylem
• Sapwood-new active xylem
STEMS-INTERNAL
Bark
Cambium
Sapwood
Heartwood
STEMS-INTERNAL
• Monocots-plant stems have vascular bundles that contain
both xylem and phloem in each bundle
• Produce one seed leaf (cotyledons)
• examples: corn, grasses
• Dicots-plant stems have the phloem layer and xylem
layer separated by cambium
• Produce two seed leaves (cotyledons)
• example: trees
STEMS-INTERNAL
Monocot
Dicot
FUNCTIONS OF STEMS
• Translocation-moves water and minerals from roots
up to the leaves and move food from the leaves
down to the roots
• Supports branches, leaves, flowers, fruits and seeds
• Video
ROOTS-EXTERNAL
• Root cap- indicates growth of new cells
• Root Hairs - absorb moisture (water) and minerals
Root
images
from a rice
plant
ROOTS-INTERNAL
• Much like stems in that they have a phloem,
cambium, and xylem layer
• Phloem-the outer layer that carries food down the
root
• Xylem-the inner layer that carries water and
minerals up to the stem
LAYERS OF ROOTS
• Fibrous-many branched shallow roots
• are easier to transplant
• Tap-long root with few branched ones
• more difficult to transplant
FUNCTIONS OF ROOTS
• Absorption-take water and nutrients from the
soil and conduct them to the stem
• Anchor the plant and hold it upright
• Store food for plant use
• Asexual reproduction in some plants
• Video
FLOWERS
• Sepals-Green parts that cover and protect
flower bud before it opens
• Petals-are really leaves that are modified to
attract insects for flower pollination, the
pretty part that we call flowers
• Stamen-male part of the flower
• Pistil-female part of the flower
FLOWERS
PARTS OF THE STAMEN
• Filament-short stalk that holds up the
anther
• Anther-a sac-like structure that contains
pollen, the male sex cells
PARTS OF THE PISTIL
• Ovules-the eggs or female sex cells that become
seeds if fertilized
• Ovary-if fertilized becomes a fruit or seed coat
• Style-holds up the stigma and connects it to the
ovary
• Stigma-sticky part on top of style where insects
leave pollen
PARTS OF THE PISTIL
Stigma
Style
Ovary
COMPLETE-VS-INCOMPLETE
• Complete flowers have both male and female parts
• Incomplete flowers have only male or female parts
FUNCTIONS OF FLOWERS
• Produce seeds used for sexual reproduction
• Attract insects for pollination (Pollination is
the transfer of pollen from anther to stigma.)
• Produce fruit to protect, nourish and carry
seeds
• Helps with seed dispersal
• Video
OBJECTIVE 3.03
• Discuss floriculture and landscape plants
TAXONOMY
• The science of classifying and identifying plants
• Scientific names are used because the same
common name is used for different plants in
different areas of the world.
KARL VON LINNE
• Swedish botanist that developed the
binomial system of naming plants
using two Latin words to indicate the
genus and species.
• Linne changed his name to the Latin
name Carolus Linneaus.
SCIENTIFIC NAMES
• Latin is the language used for scientific
classification.
• The first word is the genus and the second word is
the species. If there are additional words, they
indicate a variety or cultivar.
GENUS VS. SPECIES
• Plants in the same genus have similar
characteristics.
• Plants in the same species consistently produce
plants of the same type.
SCIENTIFIC
CLASSIFICATION
• The broadest category of scientific classification is
the Kingdom--either plant or animal.
• The broadest category in the plant kingdom is
division or phylum.
DIVISIONS
• The four most important divisions of the plant
kingdom are:
• Thallophites
• Bryophytes
• Pteriophytes
• Spermatophytes
SPERMATOPHYTES
• Contains flowering or seed-bearing plants
• Two subdivisions are:
• Gymnosperms and Angiosperms
COMMON PLANT GENUS
• Pinus-Pine
• Acer-Maple
• Cornus-dogwood
• Rhododendronrhododendron
• Ilex-Holly
• Quercus-oak
• Ficus-fig