Propagating Plants Asexually

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• Propagating Plants Asexually

Reminder student learning activities are at the
end of this power point.
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Next Generation/common Core Standards Addressed!

• MS-LS1-1. Conduct an investigation to provide
  evidence that living things are made of cells
  either one cell or many different numbers and
  types of cells. Clarification Statement
  Emphasis is on developing evidence that living
  things are made of cells, distinguishing between
  living and non-living cells, and understanding
  that living things may be made of one cell or
  many and varied cells.
• MS-LS1-7 Develop a model to describe how food is
  rearranged through chemical reactions forming new
  molecules that support growth and/or release
  energy as this matter moves through an organism.
  Clarification Statement Emphasis is on
  describing that molecules are broken apart and
  put back together and that in this process,
  energy is released. Assessment Boundary
  Assessment does not include details of the
  chemical reactions for photosynthesis or
  respiration.
• RST.6-8.1 Cite specific textual evidence to
  support analysis of science and technical texts.
  (MS-LS2-2)

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Agriculture, Food and Natural Resource Standards
Addressed!

• PS.03. Propagate, culture and harvest plants and
  plant products based on current industry
  standards.
• PS.03.01. Demonstrate plant propagation
  techniques in plant system activities. Sample
  Measurement The following sample measurement
  strands are provided to guide the development of
  measurable activities (at different levels of
  proficiency) to assess students attainment of
  knowledge and skills related to the above
  performance indicator. The topics represented by
  each strand are not all-encompassing.
• PS.03.01.03.a. Summarize optimal conditions for
  asexual propagation and demonstrate techniques
  used to propagate plants by cuttings, division,
  separation, layering, budding and grafting.

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Bell Work!

• Discuss and identify the various methods of stem
  cutting propagation.
• Discuss the methods of leaf and leaf-bud cutting.
• Describe the various types of growing media used
  for cuttings.
• Describe grafting and identify three common
  methods.
• Explain layering and the difference between
  separation and division in plant propagation.
• Explain tissue culture.
• Explain asexual propagation.

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Terms

• Cleft graft
• Clone
• Division
• Explants
• Grafting
• Hardwood cuttings
• Layering
• Leaf cutting

• Air layering
• Asexual propagation
• Bark graft
• Budding
• Callus

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Interest Approach

• Have you ever seen seeds from plants, such as the
  African violet, jade, or aloe vera for sale in a
  garden center or seed catalog?
• No, these plants are propagated asexually,
  without seeds.
• Have any of you ever propagated any of these
  plants at home. If so, how did you propagate them.

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Student Learning Objectives

• Discuss and identify the various methods of stem
  cutting propagation.
• Discuss the methods of leaf and leaf-bud
  cuttings.
• Describe the various types of growing media used
  for cuttings.
• Describe grafting and identify three common
  methods.
• Explain layering and the difference between
  separation and division in plant propagation.
• Explain tissue culture.
• Explain asexual propagation.

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Plant Propagation

• Plants may be reproduced sexually (with seeds) or
  asexually (without seeds).
• In traditional agriculture, sexual reproduction
  is the dominant method of producing new plants.
• In horticulture, both sexual and asexual
  reproduction are common methods of producing new
  plants.

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Asexual Reporoduction

• Asexual propagation is the reproduction of new
  plants from stems, leaves, or roots of a parent
  plant.
• Portions of parent plants are used to make new
  plants.

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Asexual Reproduction

• Asexual propagation allows one to
• produce more plants faster.
• propagate plants that do not produce viable
  seeds.
• produce plants that are identical to the parent
  plant.
• A plant that is identical to the parent plant is
  known as a clone.

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Stem cutting propagation

• A stem cutting is when a portion of the stem that
  contains a terminal bud or lateral buds is cut
  and placed in growing media to produce roots.

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Three basic types of stem cuttings

• Softwood cuttings - from soft, succulent growth.
• Hardwood cuttings - from one-year-old growth,
  deciduous, or evergreen plants.
• Semi-hardwood cuttings - from woody broad-leaved
  plants with new shoots.

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Leaf cuttings

• A leaf cutting consists of only a leaf blade or
  leaf blade with petiole attached.
• In the case of the leaf blade, the primary veins
  are cut and the blade is laid flat on top of the
  growing media.
• The leaf is pinned down, new plants will form at
  the point where the veins were cut.

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Leaf cuttings w/ petiole

• In the case of the leaf blade with petiole, the
  petiole is inserted into the growing media.
• Eventually, roots will form at the end of the
  petiole and new shoots will emerge from the base
  of the petiole.

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Leaf-bud cutting

• These are made from plant material having well
  developed buds and healthy, actively growing
  leaves.
• The stem is treated with a rooting hormone and
  inserted into the growing medium with the lateral
  bud just below the medium surface
• The new plant will develop from the lateral bud.

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Growing media for cuttings

• The type of growing medium used for rooting
  cuttings varies depending on the type of cutting
  and the cultural practices used.
• The media needs to hold moisture, provide good
  aeration and drainage, and be free from diseases
  and weed seeds.

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Common growing media

• Peat moss and perlite mixture - good moisture
  retention, yet provides good aeration.
• Vermiculite - good moisture retention.
• Sand - provides good aeration.
• Sand and peat moss mixture - good mix of moisture
  retention and aeration.

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Grafting

• Grafting is the process of connecting two plants
  or plant parts together so they will unite and
  grow as one.
• Plant that have been grafted consist of
• The scion, which is a short piece of stem with
  two or more buds.
• The understock (rootstock), which is the lower
  portion of the graft containing the root system.

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3 common grafting methods

• Whip-and-tongue graft - joins small scion and
  rootstock together (usuallyunder 1 inch in
  diameter).
• Cleft graft - joins small scion to larger
  rootstook usually done in winter.
• Bark Graft - similar to cleft graft except done
  in early spring when bark easily separates from
  wood.

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Budding

• Is similar to grafting except that the scion is
  reduced to a single bud.
• There are two common methods of budding
• T-Budding - taking buds from one plant and
  inserting them under bark or rootstock.
• Patch budding - bud is patched onto stem when
  the bark is thick.

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Layering

• Layering is a method of asexual propagation where
  roots are formed on a stem while it is still
  attached to the parent plant.

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Types of layering

• Simple layering - branches are bent to the ground
  and portions of branches are covered with soil.
• The terminal ends are left exposed.
• The covered portion must have a bud or buds and
  must be injured - roots should form in this area.

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Types of layering

• Air layering - this type removes a portion of the
  bark on the stem and covers it with moistened
  sphagnum moss.
• It is then covered with plastic to prevent it
  from drying out roots should form in this area.

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Separation and Division

• Some plants produce vegetative structures which
  can be separated or divided from the parent plant
  as a natural means of reproducing.

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Separation

• Method in which natural structures are removed
  from the parent plant and planted to grow.

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Division

• Method in which parts of plants are cut into
  sections that will grow naturally into new
  plants.
• Plant structures that can be separated or divided
  include

• bulbs
• corms
• rhizomes and tubers
• plant crowns

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Tissue Culture

• Tissue culture, also known as micropropagation,
  is the most recent method of asexual propagation.

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Tissue Culture

• Method of growing pieces of plants, called
  explants, on an artificial medium under sterile
  conditions.
• The explant forms a callus, an undifferentiated
  mass of cells.

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Tissue Culture Continued

• Using certain media, the callus produces roots,
  shoots, and other differentiated cells.
• This new plant has tiny leaves, stems, and roots
  that have not yet developed into normal-sized
  parts, and is called a plantlet.

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Tissue Culture Continued

• Tissue culture is common in research and
  commercial production.
• It requires special equipment and facilities and
  highly trained technicians. Tissue culture must
  be performed in sterile conditions.

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Tissue Culture Continued

• Tissue culture allows production of a large
  number of plants from a small amount of parent
  plants, in a short period of time.

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Review / Summary

• What is asexual propagation?
• What are the methods of stem cutting propagation?
• How are plants propagated using leaf and
  leaf-bud cuttings.
• Describe the various types of growing media used
  for cuttings.

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Review / Summary

• Describe grafting, what are the three methods?
• Describe the difference between separation and
  division in plant propagation.
• Explain tissue culture.

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The End!
NEXT Student Learning Activities
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Student Learning Activities

• Sample tests are available in the Lesson Plan
  tab.

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How can you grow a potato plant without a seed?

• The materials needed for this experiment are
  five potatoes each one a different size and or
  kind, three or four tooth picks for each potato,
  one clear plastic cup for each potato for each
  group.
• Have students split in to groups, give each group
  all of the materials needed. Students need to put
  the tooth picks in the potatoes, so that the
  potato will balance on the rim of the cup as
  shown in the pictures to the right. They then
  need to fill the cup with water. Have students
  write down their observations in the lab sheet on
  the next slide. Have students check on their
  potatoes and record their observations for two
  weeks. At the end of the two weeks have students
  write a lab report on this activity.

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You observe when you use your senses to gather
information. You infer when, based on
observations or past experiences, you make an
evaluation or judgment. You predict when infer an
expected future result. When your group has
finished setting up your potatoes for
observation, fill out this lab sheet. Be sure to
answer all of the question.
Name _____________________________
Observe and draw what you see. Infer what has happened and describe what you see in words. Predict what will happen at your next observation.



Day 1 Date ____________
Day 7 Date ______________
Day 14 Date _____________
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Sample Asexual reproduction Fill in each of the
boxes bellow with a definition of the word or
words above each box.
Name ___________________________________
Asexual Reproduction

Grafting Leaf cutting Tissue Culture Layering Separation and division Leaf- bud cutting Budding Stem cutting

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