and forestry occur are clearly broad areas of sci- 

 ence for which the public agricultural and forestry 

 research organizations must accept a primary ba- 

 sic research responsibility. Basic research in other 

 broad areas of science are also appropriate to ag- 

 ricultural and forestry research when clearly iden- 

 tified as mission supportive or mission contribut- 

 ing. 



The following examples are areas of science in 

 which a basic research approach is required. 

 Advances in knowledge in areas such as these are 

 important to high priority thrusts in agricultural 

 and forestry technology or to advances in institu- 

 tional arrangements and in the quality of life in 

 rural communities and homes. Necessary increas- 

 es in total resources available to the publicly 

 funded agricultural and forestry research organi- 

 zations are assumed. 



Nitrogen fixation. Adequate supplies of nitrogen 

 are essential to crop productivity. Increased crop 

 yields during the past 25 years have paralleled 

 increased use of nitrogen fertilizer. For several 

 reasons, including energy and economic costs, 

 improved or alternate technologies for providing 

 nitrogen to crops need to be developed. Research 

 in this area should determine which of the sym- 

 biotic or associated nitrogen fixation processes 

 can be modified to reduce genetic, physiological, 

 and environmental barriers to providing nitrogen 

 to crops. The possibilities include, among others, 

 in-depth exploratory research on the catalytic 

 mechanisms, control, and efficiency of nitrogen- 

 ase and associated reactions; genetics of regula- 

 tion and transfer of nitrogen-fixation genes; and 

 physiological and agronomic studies of Ni-fixing 

 microorganisms and their associated crop plants. 



Photosynthesis. Since 95 percent of the dry 

 weight of plants is a result of photosynthesis, 

 studies on this process have high priority in ef- 

 forts to improve crop productivity. The objective 

 of these studies will be to determine the funda- 

 mental biology involved in increasing net photo- 

 synthesis and to obtain more efficient partitioning 

 of the products of photosynthesis into food prod- 

 ucts of high nutritional value. Research will be 

 expanded in three major sub-areas: (I) Identifying 

 the aspects of photosynthesis that limit COt input 

 in natural environments, (2) determining the rela- 

 tionship of plant development to photosynthesis, 

 and (3) developing new methodology for plant 

 breeders to aid in identifying and incorporating 

 improved photosynthetic efficiency into crops. 



Genetic engineering for plants. The objective of 

 these studies will be to determine those plant pro- 

 cesses and characteristics that can be used by 

 plant breeders in manipulating plant genotypes to 

 increase crop productivity. Biochemists and plant 

 physiologists must be brought into direct and ac- 



tive team participation with plant breeders and 

 other scientists who work with the genetic and 

 cultural improvement of crops. Studies in this 

 area will utilize pollen cell and tissue culture tech- 

 niques to accelerate genetic improvement of crop 

 plants by (I) determining how to regenerate whole 

 plants from the cultures obtained, (2) applying the 

 principles of somatic cell genetics to understand- 

 ing the growth of higher plants, (3) performing 

 mass selective screeening for traits of agronomic 

 value, (4) employing cultures for preservation of 

 germplasm of vegetatively propagated species, (5) 

 developing selection schemes to recover process- 

 es unique to higher plants, (6) increasing genetic 

 diversity by inducing and recovering chromosome 

 changes in somatic cells, and (7) developing inno- 

 vative techniques of genetic engineering. 



Recombinant DNA. Recombinant DNA tech- 

 niques are used to join together segments of DNA 

 from different sources in a cell-free system to 

 form recombinant DNA molecules capable of in- 

 fecting a host cell and replicating either autono- 

 mously or as an integral part of the host's ge- 

 nome. The objective of this research is to im- 

 prove techniques for applying this method to or- 

 ganisms useful in agriculture. Extending the tech- 

 nique to protoplasts of higher plants and animals 

 would be a significant scientific advance. The 

 technique could be used to achieve any of the 

 many objectives of breeding in those cases where 

 traditional approaches are less efficient. Some 

 possible applications include: (1) Improved nitro- 

 gen-fixing bacteria, (2) improved bacteria for ru- 

 minant digestion, (3) improved photosynthetic effi- 

 ciency, (4) biological control of pests, (5) host re- 

 sistance to pests, and (6) improved quality of ba- 

 sic foodstuffs. 



Plant protection. Plant pests are a major limita- 

 tion to high crop productivity. Progress in reduc- 

 ing pest losses has been impeded by the rapid 

 obsolescence of available technology, by various 

 changes in production practices, and by the 

 continued penetration of pests of foreign origin. 

 Future progress requires basic research on losses 

 in production caused by pests and on adverse en- 

 vironmental effects resulting from pests and meth- 

 ods of combating them. Emphasis will be on pest 

 insects, nematodes, weeds, and pathogenic mi- 

 croorganisms. The research will be directed to- 

 ward (1) identifying and quantifying the basic bio- 

 logical and physical parameters of a particular 

 pest system such as host-pest-parasite-environ- 

 mental interactions and the dynamics of pest and 

 competitor population levels, migration, and life- 

 cycle; (2) characterizing the fundamental physiol- 

 ogy, biochemistry, behavior, and systematics of 

 pests and competitors; and (3) identifying me- 

 chanisms of plant susceptibility and resistance. 



AGRICULTURE 25 



