12 April 2022

13 February 2019

Tissue Culture - Propagating Plants

Home Plant Tissue Culture

Surprisingly it can be fairly easy to produce some plants through tissue culture in the average home. Expensive laboratory equipment and chemicals are replaced by common items repurposed to the task.

Saintpaulia, ferns, orchids and a number of other plants lend themselves to easy home tissue culture production.

While you can order a kit the best method is to attend a Home Tissue Culture Workshop where you are taught by an expierenced instructor. There is also an online group that specializes in home tissue culture.

We facilitated such a workshop in Broward County, Florida on November 5, 2011 and wish to publicly thank the University of Florida Research & Education Center in Davie Florida 33314 for their classroom and assistance - without them the workshop might not have happened. We also thank the 25 attendees who brought plants, questions and a willingness to learn a fascinating method of plant propagation.


Brief How & Why of Home Tissue Culture

by Bob G. Cannon II


While in the process of setting up workshops for plant tissue I have been asked a lot of questions. Most frequent are what advantage TC might have and how it might be done without spending a fortune on a laboratory. What follows attempts to offer answers to some of the questions I have been asked.

First let me say what Plant Tissue Culture (PTC, TC) is not. It is not against nature and not genetic engineering. It does not have to be particularly expensive or dangerous. Like grafting, gardening and changing the oil in your car you do need to follow some standard directions. Since TC started as an expensive laboratory process, requiring quite a bit of technical knowledge many of the terms used with it stem from this – for example we don’t say the directions for making a TC of African Violet but the protocol for African violet.

Most of us know that some plants will grow from cuttings – TC, in it’s simplest is using a plant’s ability to reproduce from cuttings on a very small piece of the plant. Plants from TC are identical to the parent plant, just like an airlayer or cutting. When you make an airlayer or cutting of a plant a Botanist or Horticulturist will usually call this plant a clone of the parent, TC plants are clones of their parent plant. In the garden we snip off a 2-foot branch and thrust it into the ground and it may grow. With TC we might take a part of the bud at the tip, or a part of a leaf and use it to produce a large number of new plants. Since the ‘cutting’ is very small special care needs to be taken to keep it alive long enough to make new plants. Grasshoppers and cutworms are not so much the enemy as fungus and other diseases.

Why Plant Tissue Culture?

Most new plant varieties come about because someone planted a seed and it grew into a plant whose fruit (or root or leaves) were different in a desirable way. Sometimes new varieties come about due to a mutation that occurs in a plant. (Pink grapefruits started this way, from a single branch on one tree in an entire grove of standard white grapefruit).

If a seedling variety is different enough someone will want to propagate it. It might be propagated for profit of to just spread the new plant out into the world. TC is useful here in that you can get a large number of identical plants quickly, once you figure out the protocol.

As an example: I like Hippeastrum (Amaryllis) and sometimes cross-pollinate them. Suppose I got one that had a rich blue flower, how would I propagate it to make enough to sell? I could grow the bulb and then save the offsets and cut the bulb in hopes of building up some stock over time. To get 10,000 clones would take years. I could also use TC to produce my new bulbs. With TC I would have my new bulbs much quicker. Another reason to use TC is preservation of endangered plants. Using a part of the last known living xyz plant thousands of new plants can be produced. These can then be planted in the natural range of the endangered species and spread throughout the world.

Some plants grow naturally and produce only male or female flowers, these plants are called dioecious and must have both sexes to produce seed. I know of a few plants where there is only one known sex living. These plants must be produced by cuttings or layers, as no seeds are possible. TC is also a good alternative. The most popular plant I know that is found as only one sex are some of the Lady Palms: Rhapis humilis are all male while Rhapis laoensis are all female. You might cross-pollinate them but any plants resulting from the seeds will be a hybrid combining elements from both of the parents.

Here is a last reason to use TC is more difficult to define. It can be fun. FUN? TC can be just as much a fun and rewarding part of horticulture as growing orchids, a home garden or (in my case) rare fruit. I have known people who, being dedicated to their ‘special plants’ spend decades working to grow them. Some spend far more than they will ever get back from their plants – unless you consider the rewards of success. The late William F. Whitman spent decades importing and growing rare tropical fruit that everyone knew would never grow in Florida. He, and other rarefruiters, helped bring new edibles not only to the USA but the world. If you have eaten a ‘starfruit’ or carambola in North America Bill, and a couple of other gentleman (Dr. Robert J. Knight, Morris Arkin) had a hand in putting it on your table. Bill grew his plants for fun, so did Morris.

Some readers may be in the same category of the men mentioned above, either they made plants their only job or their plants were a second job. Said another way — plants became their passion.

The How’s of Tissue Culture

The easiest way to get a plant into TC is to find a lab and hire them to do it. Not much fun in that and it can be costly.

The fun alternative is to set up your own lab. With your own set up you can participate in the joy of producing your own plants. You can work at your own pace, limited only by finance and the growth habits of the plants.

One of the most rewarding setups for the hobbyist and new professional is a home lab. Your home lab might be in a spare room or garage or it can share the space with another function. Carol M. Stiff, PhD has developed a business and an entire course aimed at those who might use their kitchens. Her Kitchen Culture web site, kits and workshops have introduced many to a fascinating new hobby. Some have even gone on to commercial labs or projects. By the way, the Home Tissue Culture Group has available all the special chemicals and equipment you need to start at home. They even sell the book Plants From Test Tubes to customers at cost. Their link is on Carol’s web site.

In a home lab the autoclave is replaced by a microwave or pressure cooker, disinfectants are found at the local store (bleach, hydrogen peroxide) and other lab equipment is improvised or done without. Recycled bottles become glass vessels for growing plants – baby food bottles are especially popular for this. You may also need sugar, baking soda, vinegar, water… Only a few additional things need to be bought that cannot be found in a grocery or drug store.

To grow a plant by TC you first need to find out is someone else has already grown it and published the protocol (directions). If they have, your task is simplified some as you know what worked. (You may still need to make a few alterations to get the best results). If you can’t find a protocol for your species of plant look for one for the same Genus or close relatives. You may be able to adapt one to your needs.

Assuming you have gathered any lab equipment, and found a protocol you have to choose your plant. Just as you would not make cuttings from a diseased plant your TC plant needs to be healthy.

What part of the plant you need depends on several things. Generally if you found a protocol that used material from a leaf you would not use material from the roots – unless your goal is to see if you can produce plants from the roots. Most of the time the plant donates a small portion and is not adversely affected. Most plants can lose a leaf or tip without great damage. You may already have pinched off a leaf from an African Violet, Begonia or Peperomia to use to start a new plant; the parent hardly noticed the loss. There are exceptions, banana being one.

To get good material for TC with a banana you generally dig up the corm and cut off the growing point. Preferably you use a “pup” for tissue culture rather than destroying the mother plant. This is cleaned, and trimmed down several times.

I have often taught that in the grove or greenhouse cleanliness is extremely important. In TC it is paramount and it is worth quoting John Wesley twice: 'Cleanliness is indeed next to godliness' - 'Cleanliness is indeed next to godliness'! You need clean plant material, clean growing areas and might even take a bath and put on clean clothes before you start a TC project. Anything you get into a culture is contamination and contamination is the main reason TC fails.

Clean plant parts, clean equipment, clean air, clean you. To get clean air many use a makeshift glove box or clean box, no need for a laminar flow hood. If you have grown orchids from seed you know about a clean box. I have seen them improvised in many ways, including fish tank, and clear plastic over collapsible PVC pipe frames.

The next step is to place your prepared plant material onto the growing medium. Growing medium? Uh oh what is this? Chances are you have planted seeds in a seed mix or cacti in a cactus mix, medium is just the TC term for the same thing – a specialized mix that gives the plant material the best chance of survival and growth. To give the details of growing this into tiny plants or explants is beyond the scope of this article and one of the reasons I suggest taking a workshop.

You can’t really take the science out of tissue culture, but you can simply the process and methods so that you do not need an expensive lab and a Ph.D. for success. If you want to give TC a try you may want to know some of these terms below.

PTC is done on various plant parts including:
Buds
Stems
Leaves
Roots
Corms
Bulbs

Each plant part has special requirements and may have its own method name. For example TC using a bud (growth point of a plant) is a meristem culture.

Medium — what you grow the plant material in. Mediums are frequently given exotic sounding names (usually after the people who first made them) the most popular seems to be Murashige & Skoog (MS) which is modified many different ways depending on the plant. The medium contains what the plants need to use as they grow, much like garden compost.

When you grow a tiny developing plant in a culture it is called an explant. This is just another stage of growth in the plants life similar to growing fern from spore and watching it pass from gametophyte to sporophyte.

Protocol — the directions methods or techniques used to TC a particular plant. Some protocols can be difficult to locate. A good place to start is with someone with wide experience. If all else fails, or you want to save some time, drop Carol an email and she probably has a reference or knows someone who has cultured your plant.

Botanical Name, Latin Name or Binomial — the scientific name of the plant. When looking for information about a plant on the Internet, or in research publications it sometimes is better to use the Latin name for a plant to avoid confusion. The two parts of the name are the Genus and species. (This is reversed from peoples names in North America as the species name is equal to a given name). An example might be in searching for a protocol for African violet. Many different flowers have daisy as a part of their common name and the protocol that works for one may not work for another. Some countries may not even refer to the plant by the common name. The scientific name you want is most likely: Saintpaulia ionantha or Saintpaulia spp.

Many plants are named after their discoverers and African violet is named after a German Baron, Walter von Saint-Illaire, who discovered the plant in East Africa.

If you cannot find a protocol for the species or Genus (it is always capitalized) sometimes looking for members of the same Family helps. African violet is in the Gesneriaceae – in most of my botanical books family names in all caps to emphasize their importance, GESNERIACEAE. Almost all family names end in aceae or ae. (SOLANACEAE = tomatoes, peppers, potatoes, tobacco; PALMAE = coconut, jelly, ivory, parlor palms). A plants scientific name is forever – unless it gets changed! This same basic system is used for all living things. (It was formalized by a talented Swedish man (Botanist, Doctor and Zoologist) in the 1700’s. His name was Carl von LinnĂ© although you may see it as Carl Linnaeus. Using his system he Latinized it to: Carolus Linnaeus, which also appears. A full copy of the code can be found at the site below. It is NOT light reading: http://www.botanik.univie.ac.at/iapt/s_ICBN.php

One last thing on using scientific or proper names: Scientific names are nothing to be ashamed of, it is not putting on airs to use them. BUT if you insist on using scientific names exclusively, and correct all friends who do not share your enthusiasm you risk leading a solitary existence. Sometimes it is best to let a peach be a peach and not Prunus persica!

Can Plant Tissue Culture create problems?

Yes, if misused. And almost anything can be misused. In the case of home PTC the chances are not very high and the techniques and chemicals used in a home lab are mostly already in your home. Some commercial and other labs combine it with genetic engineering and a lack of proper safety protocols. I believe that this is due to a shift in research from academic control to profit motive control. You are free to disagree but I note that gene modified corn, soy and papaya contaminate several growing areas. Understand that it is a lack of proper safety protocols and not the act of genetic engineering in and of itself that is causing concern. Technically when you do any selective breeding you may be practicing genetic engineering. It is a very political area.

So, is Plant Tissue Culture for you? Do you think it might be fun or want to give it a try for the possibilities it opens up? If so, I suggest you consider taking a workshop and the best one I know of is given by Carol Stiff. I am in the process of trying to set up one now, and may try for others in the future.

Some Links:

First Page

Our instructor is Carol M. Still, PhD., President & Founder
Kitchen Culture Education Technologies, Inc
www.kitchencultureEducation.org

You may contact her direct at: carol@kitchencultureEducation.org

Rare Fruit Site: www.quisqualis.com

Information on any TC workshops I may be organizing or know about: Carol's site and watch for links and information here at: www.PropagatingPlants.org

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