Date: Fri 08-May-1998

Publication: Bee

Author: SUZANN

Quick Words:

UConn-Ferris-ConnectiCulture

Full Text:

Biotech Facility Helps Boost State's Nursery Industry

(with cut)

BY SUZANNA NYBERG

STORRS -- Last month, the Plant Biotechnology Facility at the University of

Connecticut opened ConnectiCulture, a resource for the research and teaching

of plant tissue culture.

The facility allows both undergraduate and graduate students to obtain

experience in producing healthy, disease-free plants in addition to providing

the nursery industry in the state with previously unavailable plants.

"ConnectiCulture is technology transfer at its best, bringing research

expertise to commercialization. And I am immensely proud to have had a role in

the transition of this new service facility from research to commerce," said

Shirley Ferris, a Newtown resident and commissioner of the state's Department

of Agriculture.

Introduced in 1963, plant tissue culture involves growing plants in vitro [in

glass] in a sterile environment with nutrient medium. According to Dr Marc

Bridgen, the head of the facility and a professor at UConn, tissue culture

began as a means to encourage root growth in single celled plants such as

carrots and has expanded to encompass the genetic engineering and mass

propagation of plants. "Tissue culture has become an increasingly important

part of agricultural technology," he said.

Up to 50 tissue culture plants can grow in a plastic tub in a nutrient medium,

a soluble soil containing essential macro and micro elements such as nitrogen,

calcium, and phosphorus. "A nutrient medium is soil in a different form," said

Dr Bridgen. "It is the plant's own special lawn." This nutrient medium has

augur, a red algae that helps to solidify the medium so that the plant will

not sink in liquid and suffocate. "Without the augur, the plant would drown,"

Dr Bridgen said.

After being placed in the medium, the plant, which is not in sunlight and

hence does not experience photosynthesis, gets a dose of sugar. The plant also

receives two hormones, cytokinins, which encourages shoot production and

allows for mass propagation; and auxins, which helps the plant to form roots.

If a plant, however, forms callus, a clump of cells that precede the roots, a

root system might not form adequately. After the plant is put in the medium,

it is sterilized in an autoclave, a $9,000 pressure cooker that kills fungi

and microorganisms.

The advantage of tissue culture lies in the laboratory; in vitro plants can be

cultivated year-round, instead of on a seasonal basis. Among the plants that

are good candidates for tissue culture are rhododendrons, helesia, mountain

laurels, and geraniums. "It would not make sense to grow plants that grow

quickly from seed, such as radishes and zinnia, in tissue culture," Dr Bridgen

said.

According to Dr Bridgen, in the 1970s, venture capitalists, adhering to the

notion that more is better, viewed micropropagation, the mass production of

tiny plants from one mother plant in tissue culture, as the wave of the

future.

But greed is not always good. In the 1980s, Dr Bridgen said that many plants

produced mutants, not clones. Scientists discovered that propagation from

callus, instead of the root system, and high concentrations of the hormone,

cytokinin, increased the percentage of these mutations. Mutations happen all

the time in nature, Dr Bridgen noted, but if plants are propagated at such an

early stage, when one does not know whether or not they are mutations, the

result can be disastrous. "Thousands of useless plants might have to be thrown

out," he said.

In the 1990s, Dr Bridgen said that scientists learned the correct way to

micropropagate plants: slowly, without callus and without high concentrations

of hormones. Starting each year with a fresh mother plant helps to guarantee a

constant cycle of clones, not mutations. Cloning allows ConnectiCulture to

produce a large number of plants with exactly the same characteristics. The

facility can produce more than 2,000 plants a week with only a couple of

people working in the laboratory. These plants, many of which are not

available in this state, are then supplied to Connecticut nurseries. "This

helps the economy of the state," Dr Bridgen said. "It puts money here."

ConnectiCulture has the space for literally thousands of plants. In a growth

chamber lined with shelves, the plants receive a maximum of 13 hours of light

a day. "The conditions are not too harsh and not too shadowy," said Maria

Matamoro, a research associate at the facility. "These plants are pampered."

Micropropagated plants are shipped at their third stage of growth, when root

systems have formed. As they have not yet been exposed to photosynthesis, Ms

Matamoro said that they are not considered a "normal" plant. "They must

acclimate, forming a well-developed root system as well as waxy cuticles on

their leaves," she said. "Without acclimatization, plants will wilt under

outdoor stress." Most nurseries have greenhouses where plants taken from

tissue can be successfully acculturated.

ConnectiCulture propagates woody ornamental plants, including kalmia or

mountain laurel, azaleas, rhododendrons, and lilacs; it also propagates

herbaceous ornamentals, such as alstroemeria, a flowering plant hybridized and

patented by Dr Mark Bridgen. Through micropropagation, Dr Bridgen will put

alstroemeria on the market this spring, something unheard of with traditional

propagation methods.

Dr Bridgen has been doing research on the alstroemeria for the past 12 years.

Previously Van Staaveren Aalsmeer, a Dutch company, controlled the

alstroemeria market, charging astronomically high prices for both the plant

and cut flower. This price gauging raised eyebrows in the flower world,

leading to a $150,000 grant for Dr Bridgen from the American Floral Endowment

to do research on the alstroemeria. Mass propagating the alstroemeria, Dr

Bridgen reasoned, would drop the price.

Like carnations and mums, the alstroemeria is a popular flower with a long cut

life. "Unlike roses, which usually last only three or four days, alstroemeria

can last up to two weeks," Dr Bridgen said. In the United States, it is both a

popular garden flower and potted crop. With roughly 10 species in Chile and 60

species in Brazil, the alstroemeria, with its weak leaves, blooms only once a

year.

In traditional breeding, one would cross the Brazilian alstroemeria with the

Chilean alstroemeria, or the Northern Chilean alstroemeria with the Southern

Chilean, but, as Dr Bridgen discovered, many varieties of alstroemeria were

not compatible with each other. Any cross fertilization that took place was

eventually aborted.

Through tissue culture, Dr Bridgen was able to remove the alstroemeria embryo

from its seed and put it in a nutrient medium so that it would not abort.

Selecting genes for color and shape, he was able to take the genes from a

variety of alstroemeria, cross fertilize them, and grow them. As plants do not

bleed and they cannot be hurt, Dr Bridgen feels that there are few ethical

issues connected with changing a plant's genes. Any problem relating to

genetic engineering is a purely scientific, not a moral, issue: releasing a

new gene into other plants could make the plant less disease resistant.

The University of Connecticut has since patented the result of Dr Bridgen's

alstroemeria cross breeding, the "Sweet Laura," a golden alstroemeria with

orange highlights. It is the only fragrant alstroemeria. Now New Zealand and

Australian markets are looking to propagate this flower.

Micropropagation also makes plants disease-free, free of fungi and free of

bacteria. Dr Bridgen's former student, Dr Alessandro Chiari, has been studying

viruses in the alstroemeria. He used the meristem, or the tip of the bud of a

plant, to eradicate any diseases. When the extreme tip of the plant is placed

in a sterile culture, Dr Chiari can then test them for remaining pathogens.

"Once they are disease-free, they can be propagated and placed in the soil,"

Dr Chiari said.

ConnectiCulture provides equipment, biological materials, and expertise to

individuals and groups who wish to expand their efforts into areas requiring

cultured plant cells and tissues. Telephone 860/486-2021.