c/7. 1— Summary: Issues and Options • 13 
I ferenre. In miri'o-organisms. the dianges madt' 
j on tlie cellular le\el are the goals ot the 
I manipulation. With ci'ops, changes made on the 
i cellular le\ el art' meaningless unless they can he 
I reproduced in tiie entirt' plant as well. There- 
! fore, unless single cells in culture can he 
selected atul grow n into mature plants and the 
desired traits e.xpressed in the mature plant— 
procedures w hich at this lime ha\ e had limited 
success— the benefits of genetic engineei’ing w ill 
i not he w idely felt in plant hreeding. 
.Moderate success has been achie\ed for 
growing cells in tissiu' cultui'e into matui'e 
plants. I'issue culture programs of commercial 
significance in the I'nited States include the 
asparagus, citrus fruits, pineapples, and straw- 
berries. Breeders ha\e had little success, how- 
e\er, in regenerating mature plants of wide 
agronomic impoi tance, such as corn and w heat. 
Some success can he claimeil for engineering 
changes to alter genetic makeup. Both the stable 
integration of genetic material into a cell and 
the fusion of genetically different cells are still 
largely e.xperimenlal techniques. Technical 
i breakthroughs ha\e come on a species-hy- 
! species basis, hut ke\' disco\ eries are not often 
I applicable to all plants. Initial results suggest 
I that agronomically important traits, such as 
disease resistance, can be transferred from one 
I species to another. Limited success has also 
I been shown in attempts to create totally new 
species by fusing cells from different genera. 
.Attempts to find both suitable \ ectors and genes 
for transferring one plant s genes to another are 
only now beginning to show promise. 
CO\STRAI.\TS 0.\ L'SLNG MOLECULAR 
GENETICS FOR PLANT IMPRO\'EMENTS 
Molecular engineering has been impeded by a 
lack of answers to basic questions in molecular 
biolog\' and plant physiology' owing to insuffi- 
cient research. Federal funding for plant molec- 
ular genetics in agriculture has come primarily 
from the U.S. Department of Agriculture 
(USDA) and the National Science Foundation 
(NSF). In USDA, research support is channeled 
primarily through the flexible competitive 
grants program (fiscal year 1980 budget of $15 
million) for the support of new’ research direc- 
bons in plant biology. The total support for the 
plant sciences from NSF is approximately $25 
million, only $1 million of which is specifically 
designated for plant genetics. 
rhe shortage of a trained workforce is a 
significant constraint. Only a few universities 
have expertise in both plants and molecular bi- 
ology. In addition, there are only a few people 
w ho have the ability to work with modern mo- 
leculai’ techni(|ues related to whole plant prob- 
lems. ,\s a result, a business firm could easily 
de\elo|) a capability in this area exceeding that 
at any indi\ idual U.S. university. However, the 
building of industrial laboratories and suhse- 
c|uent hiring from the universities could easily 
cleplete the expertise at the university level. 
With the recent investment activity by many 
bioengineering firms, this trend has already 
begun; in the long-run it could have serious con- 
sequences for the ciualitv and quantity of uni- 
versity research. 
GENETIC VARIABILITY, CROP VULNERABILITY, 
AM) THE STORAGE OF GERMPLASM 
Successful plant breeding is based on tbe 
availability of genetically diverse plants for the 
insertion of new genes into plants. The number 
of these plants has been diminishing for a varie- 
ty of reasons. However, the rate and extent of 
this trend is unknown; the data simply do not 
exist. Therefore, it is essential to have an ade- 
quate scientific understanding of how' much ge- 
netic loss has taken place and how^ much germ- 
plasm (the total genetic v'ariability available to a 
species) is needed. Neither of these questions 
can be answered completely at this time. 
Even if genetic needs can be adequately iden- 
tified, there is disagreement about the quantity 
of germplasm to collect. Furthermore, the ex- 
tent to which the new genetic technologies will 
affect genetic variability, vulnerability, or the 
storage technologies of germplasm has not been 
determined. As a result, it is currently difficult, 
if not impossible, to state how much effort 
should be expended by the National Germplasm 
System to collect, maintain, and test new gene 
resources (in this case as seed). 
Finally, even if an adequate level of genetic 
variability can be assessed, the real problem of 
vulnerability— the practice of planting only a 
