2 
Agricultural Concerns. 
Dr. Nightingale asked Dr. Tolin to introduce the topic. Dr. Tolin began by 
questioning what RAC would envisage when it evaluates the introduction and 
dissemination of bioengineered plants into the environment. She noted the 
most of the important agricultural crops are not native to the U.S. and have 
bpen introduced. 
Dr. Tolin said the U.S. Department of Agriculture (USDA) , as well as university 
scientists and private individuals attempt to improve the germplasm of crops 
by collecting and maintaining specimens of the species. Collected seeds enter 
directly into the U.S. Plants and plant parts are subject to quarantine for 
periods of up to two years, until they are shown to be pathogen free. There 
are few restriction on importing germplasm. She then described breeding pro- 
cedures, noting that limitations do exist on what can be crossed; some plants 
are self-pollinating, some are self-sterile, and seme plants are only propagated 
vegetatively. She noted that traits such as yield are controlled by several 
genetic determinants; some traits, however, can be attributed to single genes. 
She said the situation in plants is more complicated than in mammals as many 
plants are polyploids, and thus, even if a trait can be attributed to a single 
inherited gene, multiple copies of that gene may be present. 
Working groups and associations working with a particular crop species meet and 
determine procedures and guidelines for any particular species. Dr. Tolin said 
most breeding and selections are performed on land controlled by members of the 
group doing the research and testing. When the "elite” lines have been 
selected, these lines are then evaluated under varying conditions in field 
tests. Generally, these tests are conducted in several different areas around 
the country. State and Federal government and private industry are involved 
in this type of testing. State government laboratories usually work closely 
with agricultural experiment station and land-grant university scientists. 
These ventures, however, are primarily of an economic nature. State government 
laboratories test and rate seeds for trueness to type, germination potential, 
etc., and are often involved in seed distribution. They set standards for 
seed certification that are met by commercial seedsmen, often in accordance 
with local guidelines or laws. Vegetatively propagated plants follow the same 
scheme and often have more stringent requirements for certification (i.e., 
they must be virus free). 
Dr. Martin asked Dr. Tolin if there were any instances of a plant originally 
thought to be beneficial, beccming a weed. Dr. Tblin offered the example of 
"Johnson grass" vhich was introduced into the U.S. because it is hardy and 
possesses a high stress tolerance. The grass, however, became a pest. It can 
be controlled, however, by herbicide application. Dr. Milewski noted that she 
had included the document "Spread of Organisms with Novel Genotypes: Thoughts 
from an Ecological Perspective" in the desk folders. This document discusses 
the introduction of Johnson grass and the establishment of other plants and 
organisms as pests in new ecosystems. 
