Friday, March 27, 2015

Investigating Cloning Plants with Rooting Hormone

The typical method plants use to reproduce is through seeds.  Reproducing with seeds allows for genetic variation.  There are other ways plants can reproduce.  One way is by cloning.  Cloning is when an entire organism is created from a piece of the original.  They are genetically identical.  Typically the leaves, stems, or a splitting from the original plant is used.  At the end of the cutting there is a mass of non-specialized cells called callus.  The callus, with the help of the correct hormone, is capable of growing into whatever cells are needed.  It is amazing to think a leaf can begin growing roots and stems to produce new plants.  It is a great way to get a new plant in the house without spending money.
Some plants work better than others.  Recommended plants are begonia, coleus, geranium, ivy, and philodendron.  In this investigation we will be cloning new plants by using the stem with several leaves attached. 

When cloning plants it is best to use rooting hormone.  Plants contain many different kinds of hormones.  Hormones are chemicals produced by the plant that control plant growth.  Hormones send a signal telling the plant cells what to do.  One important hormone is called auxin.  Auxins control many functions in plants.  They are created in the apical meristem.  The apical meristem is located at the stem and root tips.  One function of auxins is to help initiate root growth.  When cloning plants it is best to use rooting hormone (auxin) because it will increase the odds of growing a healthier plant.  Root development should happen faster and the roots should be healthier. 

The conditions of the room are important too.  Make sure the room is warm.  The plant cutting will be delicate so do not put it in direct sunlight where it can dry out.  It will most likely take a month or more to get good root development.  Be patient. 
 Lets' Get Cloning
House Plant Cuttings        Water           Rooting Hormone         
       16 oz. Plastic Bottles                                Warm Sunny Location
       Permanent Marker                                  Ruler
1. Cut a 15 inch stem from the plant.  Cut the stem at a slight angle.  Remove any lower leaves.  You should have 2-3 leaves  or more at the top.
2. Fill the bottle 3/4 full of water.
3. Dip the stem in the water.  Then dip the stem into the rooting hormone only 1-2cm high.  This will put  rooting hormone on the end of the stem.

4. Place stem in the bottle.
5.  Place the bottle in a warm sunny location and observe for 1 month or more.
· Take weekly observations to keep track of any changes.
· If the water evaporates below the roots make sure to add more.  You do not need to add more hormone.
· If the water gets bad change the water.  I would not add hormone and assume the plant had a good start with it.  
· Many garden centers will have the correct types of plants. 
Where do I get rooting hormone?
The large home improvement stores typically carry it.  A local garden center can also help.  It is also available on-line.  This activity uses the powdered form.
Grade Level  Series
Turn cloning into an investigation.

This investigation is part of a series.  The investigation is  available for K-1, 2nd/3rd and 4th/5th grade.  The K-1st grade journal focuses on with or without rooting hormone.  The 2nd-3rd grade journal focuses on the amount of rooting hormone and students do 3 tests.  The 4th-5th grade journal focus on the same concept as the 2nd-3rd grade journal, but students will do 3 trials of each and calculate the average.  The grade level adjustments make it a great way for a homeschool class to teach the same concept to multiple ages.  It also is great for science fairs.  All journals are found at: