Chapter 17 Tissue Culture: Micropropagation 431
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• Lewis Knudson germinated an orchid embryo
in vitro in 1922, Figure 17-2.
• The fi rst plant hormone, indole acetic acid
(IAA), was discovered in 1926 by Fritz W. Went.
• In 1939, constant regeneration and
proliferation of plants was achieved by
scientists Roger J. Gautheret, P.R. White, and
Dr. P. Nobecourt.
• Coconut milk was added to the growth
medium and plants began to thrive with the
addition of this compound, as discovered by
J. Van Overbeek in 1941.
• In 1946, Professor Ernest Ball raised whole
plants of lupine in vitro. This was the fi rst
entire plant grown via tissue culture.
• In 1962, Toshio Murashige and Folke Skoog developed the fi rst reliable
standardized artifi cial medium for micropropagation.
Advantages and Disadvantages
As with other propagation methods, micropropagation has advantages
and disadvantages. Horticulturists continue to use micropropagation for the
many advantages it offers, including:
• The uniformity of clones in age, quality, and desired characteristics.
• The ability to grow large numbers of plants in small spaces in a short
amount of time.
• The ability to produce a viable plant when breeding plants that are not
usually compatible.
• The ability to generate vast quantities of clones from one plant.
• The ability to produce pest-free plants (at the time of distribution from
the laboratory).
• The ability to aid in the conservation and replication of rare or
endangered plant species.
Did You Know?
There are nearly
150,000 orchid
hybrids. Orchids were
the first plant to be
micropropagated
and are currently
the most commonly
micropropagated.
nakorn/Shutterstock.com
Figure 17-2. These orchids are the result of
micropropagation.
Thinking Green
Joxemai/Wikipedia
Gelidium sesquipedale
Micropropagation Uses a Sustainable Product
Technicians, or culturists, typically use agarose
to create the medium of growth. Agar, derived from
a red algae’s cells, primarily comes from the genera
Gelidium and Gracilaria. This seaweed substance is
plentiful and easily replenishes itself. Some forms of
these algae are being researched as potential biofuel
sources.