430 Horticulture Today Copyright Goodheart-Willcox Co., Inc.
History
Although micropropagation
celebrated its 100th anniversary in 2004,
many horticulture professionals consider
this propagation technique as still in
its infancy. However, this technique
is considered to be one of the most
technologically advanced methods of
propagation. The earliest advances in
tissue culture began in the early part of
the nineteenth century and the majority of
micropropagation protocol was created in
the 1940s through the 1960s.
• In 1839, scientists Matthias Schleiden and Theodor Schwan proposed
that all life could be grown from a single cell. They determined that
a single cell contains all of an organism’s genetic information and the
ability to differentiate into any type of cell. This is known as totipotency.
• Gottlieb Haberlandt conceptualized the idea of in vitro cell culture in
1902. In vitro is Latin for “in glass.” For scientifi c purposes, in vitro
refers to the growth of an organism outside the body, such as in a test
tube or petri dish. Haberlandt was able to isolate cells and put them in
culture, but never successfully had the cells divide.
• Plants embryos were cultured by E. Hannig in 1904.
Tissue
culture is a collection of techniques used to grow plants in a
nutrient medium under sterile conditions. Micropropagation, also referred
to as tissue culture, is an asexual propagation method in which plants are
manipulated on a cellular level, causing them to duplicate themselves
repeatedly and rapidly. This process is important in the agriculture and
horticulture industries because it quickly produces identical plants (clones).
Using this method of asexual propagation, very small pieces of plant tissue
are placed in a sterile culture or test tube that contains a distinctive growth
medium (a substance containing nutrients and hormones used for plant
growth), Figure 17-1. Ultimately, cells divide to create new tissues and
organs. The fi nal result is a new organism: a cloned plant.
When a plant cannot be produced from seeds (sexual propagation),
breeders can use micropropagation to quickly produce the plant. (Keep
in mind that sexual propagation is still the least expensive and fastest
way to disseminate new varieties if the plants can be produced by
seeds.) Micropropagation is a form of biotechnology in which plants are
being manipulated using science, and cells and entire plants are cloned.
Micropropagation is an essential tool used by horticulturists, mostly
professionals, in today’s thriving green industry.
borzywojo Studio/Shutterstock.com
Figure 17-1. Micropropagation is accomplished using a sterile
technique by technicians who specialize in micropropagation.