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Shands, H.L. and G.A. White. 1990. New crops in the U.S. national plant germplasm system. p. 70-75. In: J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press, Portland, OR.

New Crops in the U.S. National Plant Germplasm System

Henry L. Shands and George A. White


  1. THE NATIONAL PLANT GERMPLASM SYSTEM
  2. NPGS AND NEW CROPS
    1. Amaranthus spp. (Amaranth)
    2. Crambe
    3. Guayule (Parthenium argentatum)
    4. Meadowfoam (Limnanthes spp.)
    5. Seed Oil Sources of Epoxy Fatty Acids
    6. Kenaf (Hibiscus cannabinus) and Roselle (H. sabdariffa)
  3. SUMMARY
  4. REFERENCES
  5. Table 1
  6. Fig. 1

THE NATIONAL PLANT GERMPLASM SYSTEM

The National Plant Germplasm System (NPGS) has recently been characterized in detail (Shands, et al. 1988, and White et al. 1989). The NPGS is described as a user-driven system whose repositories are principally funded and managed by the U.S. Department of Agriculture's Agricultural Research Service (ARS) with significant financial and operational input by the State Agricultural Experiment Stations (SAES). Principle functions of the NPGS are the acquisition, preservation, evaluation and distribution of plant germplasm of economic food, fiber and industrial crops. The policy of the USDA is to distribute germplasm freely for bonafide research on a worldwide basis.

The NPGS consists of operational, advisory, and administrative units that provide appropriate support to serving users. Operational units (Fig. 1) consist of working collections at regional Plant Introduction Stations (RPIS) located at Ames, Iowa; Griffin, Georgia; Geneva, New York, and Pullman, Washington; National Clonal Germplasm Repositories (NCGR) at Brownwood, Texas; Corvallis, Oregon; Davis, California; Geneva, New; York; Hilo, Hawaii; Miami, Florida/Mayaguez, Puerto Rico; Orlando, Florida; and Riverside/Brawley, California; and, numerous individual sites with individual commodity and genetic stock collections. The National Seed Storage Laboratory (NSSL) at Ft. Collins, Colorado houses the base collection for the NPGS.

Additional support units consist of those in the Germplasm Services Laboratory (GSL) and National Plant Germplasm Quarantine Laboratory (NPGQL) of the Plant Sciences Institute, Beltsville, Maryland. Offices of the GSL include the Plant Introduction Office (PIO), Plant Exploration Office (PEO) and the Germplasm Resources Information Network (GRIN) Database Management Unit (DBMU). The NPGQL is physically located in the( National Plant Germplasm Quarantine Center (NPGQC) operated jointly with the Animal and Plant f Health Inspection Service (APHIS) of the USDA which has regulatory responsibility for the international movement of plants and plant parts used in the germplasm program.

The NPGS is unique in many ways but most importantly in that it is a loosely, coordinated network of Federal, State and private industry organizations and individuals with a common goal for acquiring, preserving, and developing plant germplasm. The NPGS has direct linkages to both national and international persons, institutions, and official outlets for acquiring material which could benefit the scientist. There are many individuals who are very actively engaged in plant selection and improvement who obtain plant materials through their own means. They literally bypass the system, to their own and the system's disadvantage. Likewise, material going directly to the scientist is a loss to other scientists in the future. Even if it does get into the NPGS, often the passport data (source, origin, field collection, descriptive and other information) are lost or are potentially inaccurate with possible transcription errors as a result of the delay. It is most desirable that newly acquired material be included in the NPGS, that appropriate plant introduction (PI) numbers be assigned, and that passport data be entered into the GRIN database. It is the responsibility of individual scientists to be cognizant of their part in helping to meet the Nation's need for preservation of germplasm and maintenance of biodiversity. Preservation of these materials for future generations of scientists cannot be overemphasized. Original material, reflecting the full diversity of the samples acquired, along with accurate passport information, should be submitted to the appropriate NPGS working collection. Associated data are incorporated into the GRIN and seeds sent, usually after an increase, to the base collection at NSSL for long term preservation.

NPGS AND NEW CROPS

The "golden new crops" of North America—soybean in the United States and rapeseed in Canada resulted from dedicated, sustained research efforts and the availability of germplasm. Herein lies the foundation for successful establishment of new crops. The NPGS's role is to assemble, document information, and maintain the integrity of new crop germplasm placed under its care. Researchers are urged to donate genetically unaltered wild accessions and advanced lines/releases/cultivars to NPGS for safekeeping. To avoid orphanage treatment of new crop germplasm, basic descriptors for evaluation and advisory groups are needed to strengthen germplasm activities and enhance utility of available germplasm in improvement programs. While some potential new crops can be effectively researched by scientists of one or of a few states, national input, including coordination of agronomic and chemical research are desirable because of national implications and possible shifting of production areas.

In 1956, the Agricultural Research Service (ARS), through the New Crops Research Branch and the Regional Research Centers (utilization laboratories), embarked on a systematic and highly successful program to identify potential new crop leads and to develop the most promising ones. The initial emphasis, because of large crop surpluses, was directed to industrial use such as new oilseeds, seedgums, natural pesticides, and fibers for paper pulp. Unfortunately, support ebbed as time passed and the farm economy fluctuated. Support for breeding and cultural research proved very inadequate to follow up on the many promising leads. These efforts were highly cooperative and involved state, federal, and private research, with a good mix of chemistry, processing and agronomic research. This kind of cooperation is essential for success. The USDA Regional Research Center at Peoria, Illinois actively complements the existing new crop agronomic research with chemical analyses, processing studies, and product development research.

The remainder of this paper is devoted to the germplasm status within NPGS of selected new, crop species. The following benefits of the NPGS are particularly important:

Amaranthus spp. (Amaranth)

Species within this genus range from serious weeds to ancient grains. Amaranth has been cultivated in the Andes and in Mexico for centuries as a good quality, high lysine grain crop. More recently, Africans began to grow certain species as a vegetable similar to spinach and other greens. Campbell and Abbott (1982) field evaluated 20 entries of vegetable amaranth in Maryland. Amaranth is an established new crop in the U.S. albeit, on low acreage and has a bright, continuing future as a specially crop for health foods (grain and vegetable) and an ornamental. There is a vast reservoir of germplasm in the NPGS (see Table 1). Many accessions are unidentified at the species level, thus much will be required in taxonomy and evaluation. Additional germplasm should be available through exchange and field explorations. Yield increases and increased seed size of grain types would enhance amaranth as a new crop and additional evaluation of the germplasm would be helpful in improving these and other characters. Rodale Research Center researchers have been leaders in the development of amaranth as a new crop both in the U.S. and abroad (Cole 1979). They have identified preferred accessions for grain and garden vegetable production and recently established a core collection. A large portion of their collection is being characterized and added to the NPGS collection at Ames, Iowa. Amaranth is becoming a common ornamental.

Crambe

The new crops program identified C. abyssinica as a good new crop prospect in 1957 because of the high level of erucic acid (60%) in the seed oil, and good agronomic characteristics. Subsequent agronomic research resulted in the delineation of potential production areas (White and Higgins 1966) and in the development of five cultivars ('Prophet,' 'Indy', and 'Meyer' by Purdue University researchers and 'BellAnn' and 'BelEnzian' by Campbell et al. 1986a) and three germplasm releases (Campbell et al. 1986b). Limited genetic diversity in available germplasm of C. abyssinica has hindered major progress in yield improvement (Lessman and Anderson 1981, Lessman and Meier 1972). Only a few accessions are known to have come directly from the wild. Accessibility of undoubtedly limited wild germplasm in Ethiopia, the center of origin, is poor. Nonetheless, crambe has been successfully grown in several areas on a large field scale. A sustained breeding effort to increase yield and improve disease resistance, especially to Alternaria, is needed. Generic diversity for low or zero thioglucosides in the seed meal could enhance the economics of crambe production through development of a superior protein-rich feed supplement.

G.A. White, K.J. Lessman, and K. Meyer (unpublished) collected seed of other Crambe species in several Mediterranean countries in 1974. While these species generally had desirable erucic acid and seed oil levels, they offered little to the agronomic development of crambe as a new crop. White and Solt (1978) identified three ploidy levels in C. kralikii which could be useful in obtaining more cold tolerance in C. abyssinica. Leppik and White (1975) delineated the natural distribution of Crambe species. Shortly thereafter, wild populations were discovered in Turkey.

Guayule (Parthenium argentatum)

This natural rubber-bearing species is native to Southwestern United States and adjacent areas in Mexico (Thompson 1989). Considerable research was conducted on guayule during and following World War II because foreign supplies of natural rubber were threatened. When the research was phased out, seed of 25 lines was deposited in the NSSL. With renewed interest in new crop development, these lines provided the basic testing materials until the germplasm base could be greatly expanded through field collection. Only 33 accessions reside in the NPGS. Numerous accessions have been collected from the wild but these have not been tendered to the NPGS for maintenance. The importance of maintaining the original integrity of germplasm through proper growout sample size, pollination control, and storage cannot be overemphasized. Improved yield and rubber content will be highly dependent on availability of diverse germplasm.

Meadowfoam (Limnanthes spp.)

This is a native North American genus whose most common species is L. alba. Seed oils are rich in longchain fatty acids (C20 and C22). Research on meadowfoam has been conducted at Oregon State University and the University of California-Davis for several years and superior genotypes of L. alba have been released by Oregon researchers and tristate (Oregon, Washington, and Idaho) cooperation has promoted continuing research and attempts to commercialize meadowfoam (Jolliff 1981).

According to Table 1, there are 58 accessions of meadowfoam in the NPGS. Researchers in California and Oregon hold substantial germplasm. Again, provisions for pollination control when increasing each accession, and maintenance under good cold storage conditions are important features for continuing research. Improved seed yield, increased height and erectness, and less seed shattering would enhance the crop potential of meadowfoam.

Seed Oil Sources of Epoxy Fatty Acids

According to Princen (1979), the U.S. consumption of epoxy fatty acids is about 140 million pounds annually and expanding. There are no commercially available natural sources of epoxy oils. Herein, we consider two genera that contain seed oils rich in epoxy acids.

Stokesia laevis (Stokes aster). This plant is monospecific and native to the Southern and Southeastern United States (Gunn and White 1974). Campbell (1981) discussed its agronomic potential. A breeding program was initiated at Beltsville to select for improved seedling vigor and seed retention within broad-based populations derived from early- or late-flowering plant introductions. Two early and four late-flowering synthetics resulting from this research have been increased and germplasm will be released in 1989 (T.A. Campbell, unpublished data). This perennial species should be a prime candidate for new crop development because of the following factors: ready accessibility of germplasm; wide diversity in germplasm; high seed oil content (27-44%) and high epoxy acid content (63-79%) (White 1977); and adequate seed retention. Research is needed to speed up stand establishment, to conduct sustained management studies of this perennial, to establish an aggressive plant improvement program, and to continue processing and product development studies. While germplasm is readily available, some of the smaller wild populations and those along roadsides are especially vulnerable to extinction. Despite little present-day ongoing agronomic research, we consider Stokes aster the best U.S. new crop prospect for natural epoxy fatty acid production.

Vernonia. This genus is widespread in India, Pakistan, and Africa. There are two weedy naturalized perennial species in the United States. After the 1954 discovery of vernolic (epoxy) acid in V. anthelmintica, the new, crops program identified this species as a prospective new oilseed crop. Subsequently, extensive field work ensued including breeding efforts at Purdue University. Considerable diversity for various traits except for seed retention was identified (Berry et al. 1970). Harvesting trials in three states on a several acre basis showed that with improved seed retention, conventional combine harvesting would be feasible. Breeding efforts resulted in the development of relatively determinate and earlier maturing types, however little generic variability for better seed retention was found. Also, a bitter resinous principal associated with the heads and seeds proved very disagreeable in harvesting and processing of seed. While some large seedlots were introduced from India, sampling of wild populations throughout the range of V. anthelmintica was inadequate.

V. galamensis is distributed in several African countries (Perdue et al. 1986). It exhibits better seed retention and higher oil content than V. anthelmintica. However, it presently has little crop potential for continental U.S. because of its short day requirement. There is limited germplasm in NPGS but recent field collections will provide a much broader base of germplasm. According to R.E. Perdue (personal communication), an estimated yield of 2.5 t/ha was obtained from experimental plots of unimproved V. galamensis in Zimbabwe. Approximately 32 accessions of V. galamensis (two or more accessions each of the six subspecies) have been collected from various African countries but not all are available to the U.S. at this time.

Kenaf (Hibiscus cannabinus) and Roselle (H. sabdariffa)

These species have been grown for many years in various countries as sources of cordage fiber. The U.S. had a project at Belle Glade, Florida that emerged from the war effort when supplies of cordage fiber products were seriously threatened. Researchers released two cultivars-'Everglades 71' and 'Everglades 41' (Wilson et al. 1965). Kenaf was identified in 1960 as a prime new crop prospect for paper pulp. New crop researchers conducted extensive cultural research at several locations (White et al. 1970) using 'Everglades' and other cultivars that were provided by the Belle Glade research unit. Research support especially for agronomic/breeding has fluctuated with a recent period of no effort on the production side.

Interest has been rekindled primarily through the determined effort over several lean research years by Kenaf International to commercialize kenaf in the United States. This company has developed plans for a mill in south Texas dedicated to kenaf for newsprint pulp. Processing, pulping, and other trials to promote the commercialization of newsprint manufactured from kenaf has been summarized by Kugler (1988). The future crop status of kenaf appears very favorable.

The germplasm status for kenaf and roselle is summarized in Table 1. In addition there are numerous breeding lines from the Belle Glade program that need to be carefully inventoried, perhaps many composited, and evaluated. The authors suggest the following germplasm related activities:

  1. Develop a complete inventory of seedstock holdings of kenaf, roselle, and other closely related Hibiscus species.
  2. Initiate a systematic evaluation and increase of germplasm accessions.
  3. Arrange for the proper identification, increase, and screening for nematode reaction of the 1979 Jones collection from Africa.
  4. Introduce and evaluate current cultivars of kenaf and roselle from other countries.
  5. Establish a sustained, well-supported, and nationally coordinated breeding program.
Internationally, the interest in kenaf for pulp and fiber remains high. The same may be said for roselle. For example, C.A.B. International listed 167 annotated references for kenaf (1988a) and 71 for roselle (1988b) with most published during 1980-85.

SUMMARY

New Crop success stories and consideration of several potential new crops have been discussed at this symposium. The future will undoubtedly bring other crop prospects for food-to increase nutrition and dietary variety such as the Andean crops, natural pesticides, medicinal plants, and perhaps many with industrial-use potential. There will always be the need for ample, well-documented germplasm of the species involved.

The NPGS is unique in its mission to acquire, evaluate, maintain, and distribute plant germplasm and to manage associated data. Germplasm of potential new crops, so critical in their development, needs to be maintained in an unaltered state to preserve diversity. New crop researchers are urged to provide complete passport data when donating germplasm to NPGS for safekeeping.

While the germplasm base of most if not afl of the new crops discussed herein needs to be expanded, thorough assessment and increase of available accessions in a systematic manner are imperative. Appropriate descriptors and descriptor implementation plans are needed for obtaining the desired and important data which will enhance the germplasm utility. The NPGS has and will continue to play an important role in new crop development through germplasm maintenance, evaluation, and distribution.

REFERENCES


Table 1. Constituent of interest and germplasm status in NPGS of selected new crop species.

Scientific name Common name Constituent of interest Site No. of NPGS accessions Remarks
Amaranthus spp. Amaranth Food-grain & vegetable, Ornamental Ames, IA 2,554 Many unidentified accessions in working collection
Crambe abyssinica Crambe Oilseed-high erucic acid Ames, IA 164 Variability low. Need more wild accesions. Five cultivars.
Crambe spp. Oilseed-high erucic acid Ames, IA 121 Poor agronomic traits.
Cuphea spp. Cuphea Oilseed-short chain fatty acids Ames, IA 360 New accessions recently acquired. Exploration activity.
Hibiscus cannabinus Kenafz Annual source of paper pulp Griffin, GA 284 Germplasm evaluations needed. Introduce foreign cultivars.
H. sabdariffa Roselle Annual source of paper pulp Griffin, GA 94 Resistant to root-knot nematodes. Yields lower than for kenaf.
Limnanthes spp. Meadowfoam Long chain fatty acids Pullman, WA 58 Considerable germplasm not in NPGS
Parthenium Guayule Natural source of rubber Ft. Collins, CO 33 Need for higher rubber content and improved yield. Germplasm must be maintained & properly documented.
Stokesia laevis Stokes aster Oilseed-epoxy fatty acid, ornamental Griffin, GA 34 Germplasm readily accessible. Cultural management and breeding research needed.
Vernonia anthelmintica Ironweed Oilseed-epoxy fatty acid Ames, IA 19 Narrow germplasm collection. Seed shattering. Amenable to machine harvesting, Bitter principle associated with seed and seed head.
V. galamensis Oilseed-epoxy fatty acid Griffin, GA 10y Good seed retention and yield potential. Short day requirement.
zThe 1969 Jones collection from Africa not included. It contains accessions of kenaf, roselle, other species, and unidentified item.
yDoes not include recent collections from Africa.


Fig. 1. Location of principal repositories and operational units of the U.S. National Plant Germplasm System.


Last update August 26, 1997 by aw