The National Plant Germplasm System (NPGS) is a network of federal and state cooperative agencies which houses germplasm of economically important crops and their wild relatives. Curators are assigned to coordinate long term collections at facilities located throughout the country for optimum crop performance. Constant awareness of germplasm outside of the NPGS system will improve the scope and value of NPGS collections. This alternate source germplasm can reside in other national germplasm collections, in breeding and research collections, in botanical gardens and arboreta, and with private companies, organizations, or individuals. New plant explorations also continue to provide additional germplasm. Many organizations and individuals have begun compiling and publishing lists of germplasm sources. A summary of lists for temperate fruit and nut germplasm will be presented as an example. Compilations of this sort are extremely useful at the time of publishing but become outdated as listed sources change, or new sources are established. Periodic updating of published compilations are thus required. Contacts with Crop Advisory Committee members, plant researchers, and professional and amateur specialist organizations are also important sources of germplasm information.
Pyrus communis L. germplasm came to North America with early settlers. Pyrus cultivars have markedly declined since the turn of the century when more than 2700 unique Pyrus cultivars and 10,000 cultivar synonyms were noted. In 1956, 844 Pyrus cultivars and selections were widely available. Fireblight, Erwinia amylovora (Burril) Winslow et al. 1923, and lack of cold hardiness were main causes of cultivated germplasm loss. During June through December 1989, I resurveyed 37 State Agricultural Experiment Stations which had pear collections in 1956, to determine the present extent of their collections. Only four had more than 100 cultivars; 12 had 10 to 100 cultivars; 21 had less than 10. Experiment stations have decreased their collections because of funding cuts and program redirection. The National Clonal Germplasm Repository at Corvallis, established in 1981, has a collection of 811 unique cultivars and representatives of 26 Pyrus species. About 194 cultivars published in 1908 are in the NCGR collection. At least 424 of those listed in 1956 still exist. Oriental species and other foreign selections not previously available are actively being acquired. About 80% of the clones in the NCGR collection are virus negative; about 10 % reside in backup in vitro storage. Fireblight damage has not been observed thus far. With continued federal support, Pyrus germplasm availability should remain more stable than the decline seen in the last 90 years.
The cover photograph, by Joseph Postman, Plant Pathologist, USDA/ARS, demonstrates a portion of the unique diversity of Pyrus germplasm within the collection at the National Clonal Germplasm Repository (NCGR) in Coivallis, Ore. Each of the fruits in the photograph is a pear species, hybrid, or cultivar.
The pear, Pyrus L., originated in prehistoric times. Records of its cultivation date back 3000 years both in Europe, with the ancient Romans and Greeks, and in Asia, with the Chinese. Pear culture was significant in France and England by the 16th century. The European golden age of pear improvement occurred from the 17th through the 19th centuries. The pear genetic resource collection for the United States Department of Agriculture, Agricultural Research Service, National Plant Germplasm System is maintained at Corvallis, Ore. This collection preserves more than 2000 diverse pear accessions, represents 26 species, and includes more than 410 heirloom cultivars. At least 10 of the cultivars have obscure origins from the ancient Roman, Greek, or Chinese cultures. Another dozen are at least 400 years old, and more than 250 were introduced during the European golden age. Another 120 “antique” cultivars of the collection were introduced during the first half of the 1900s. The “big four” economically important Pyrus communis L. cultivars in the United States, `Bartlett', which originated in 1777; `Anjou', late 1700s; `Bosc', 1807; and `Comice', 1845; are also represented. Origin and background information for these heirloom clones is web accessible through the Germplasm Resource Information Network (GRIN) database. Although many ancient pear genotypes have been lost, the Repository staff continues to search for significant heirloom cultivars that are not yet represented. Besides having direct value in crop improvement, these plants are a significant part of our human heritage. Their preservation is a sacred trust.
N.I. Vavilov’s theories direct present-day global activities in plant science, breeding, and conservation. His expeditions around the world located centers of diversity of crop evolution. Vavilov was one of the earliest scientists to realize that wild genetic diversity could be lost, through genetic erosion, reducing the possibilities for future crop improvement. To measure genetic erosion, Gary Nabhan and colleagues traveled in 11 countries following routes that Vavilov had taken more than half a century before. The detailed notes concerning the vegetation and flora that Vavilov observed could be used as a baseline in contrast with Nabhan’s plant and cultivar inventories to observe changes in plant diversity at specific sites. The objective of this manuscript is to summarize potential genetic erosion at three case study locations, the Pamiri Highlands of Tajikistan, the Ethiopian Highlands, and the Colorado Plateau of Southwestern North America. At these localities Vavilov’s notes can be compared with the agricultural activities of the modern day. In each case, significant climatic, environmental, and human-caused changes have affected the local agriculture during the intervening years. Localities that have retained diversity have suffered the least. Reduction of diversity is associated with decreased agricultural stability and productivity. Programs encouraging farmers to manage diversity and promote involvement of local youth in agriculture may reduce or moderate the effect of genetic erosion.
The genus Rubus L., indigenous to six continents, includes blackberries, raspberries, and their hybrids and is commonly referred to as brambles or briers. Rubus species were a food and medicinal source for native peoples soon after the Ice Age. This short article presents only a sample of the wealth of historical reports of medicinal uses for Rubus. Brambles were documented in the writings of the ancient Greeks: Aeschylus, Hippocrates, Krataeus, Dioscorides, and Galen; Romans: Cato, Ovid, and Pliny the Elder; Asian medicinal traditions; traditional Chinese medicine; and the Ayurvedic tradition of India. Folk traditions of native peoples throughout the world have also applied Rubus for multiple medicinal uses. Although in modern times Rubus is grown for its delicious and vitamin-rich fruit for fresh and processed product consumption, the ancients used the whole plant and its parts. Stems, branches, roots, leaves, and flowers were used in decoctions, infusions, plasters, oil or wine extractions, and condensates. Decoctions of branches were applied to stop diarrhea, dye hair, prevent vaginal discharge, and as an antivenom for snakebites. Leaves were chewed to strengthen gums and plastered to constrain shingles, head scurf, prolapsed eyes, and hemorrhoids. Flowers triturated with oil reduced eye inflammations and cooled skin rashes; infusions with water or wine aided stomach ailments. Greeks and Romans recorded female applications, whereas the Chinese described uses in male disorders. The fruits of R. chingii are combined in a yang tonic called fu pen zi, “overturned fruit bowl,” and prescribed for infertility, impotence, low backache, poor eyesight, and bedwetting or frequent urination. The Leechbook of Bald described the use of brambles against dysentery, combining ancient medicinal knowledge with pagan superstition and herb lore. Medicinal properties of Rubus continue in Renaissance and modern herbals, sanctioning leaf infusions as a gargle for sore mouth, throat cankers, and as a wash for wounds; the bark, containing tannin, was a tonic for diarrhea; and root extract, a cathartic and emetic. Recent research has measured high ellagic acid, anthocyanin, total phenolics, and total antioxidant content in Rubus fruits. Fruit extracts have been used as colorants and are now being tested as anticarcinogenic, antiviral, antiallergenic, and cosmetic moisturizing compounds. From ancient traditions through conventional folk medicines to the scientific confirmation of health-promoting compounds, Rubus is associated with health-inducing properties.
In 1999, the National Clonal Germplasm Repository at Corvallis, Ore., was assigned to preserve the hardy Actinidia Lindl. resources for the U.S. Dept. of Agriculture, Agricultural Research Service, National Plant Germplasm System. The fuzzy kiwifruit [A. deliciosa (A. Chev) C. F. Liang et A. R. Furguson] and other less cold-hardy Actinidia species, remain at the Davis Repository. The hardy Actinidia, commonly called Chinese gooseberries or hardy kiwifruit, encompass two taxonomic sections, Leiocarpae and Maculatae, and include about 13 described species. These perennial vines are natives of Asia and have been developed and cultivated in Lushan, Wuhan, and Guilin, China; Motueka, New Zealand; Kagawa Prefecture, Japan; Vladivostok, Russia; and California, Maryland, Michigan, Minnesota, New Hampshire, and New York in the United States. Thus far, the Corvallis Repository has established representatives of six species, A. arguta (Siebold & Zucc.) Planch. Ex Miq., A. callosa Lindl., A. kolomikta (Maxim.&Rupr.) Maxim, A. melanandra Franch., A. polygama (Siebold & Zucc.) Maxim., A. purpurea Rehder and 60 cultivars. These clones will be preserved as potted plants under screen. They will also be fruited and evaluated as trellised plants in the field. The repository plans to expand the species diversity of the collections. Plant requests for dormant scionwood or spring softwood cuttings are available by contacting the Corvallis Repository Curator.
The latter part of the 19th and the first several decades of the 20th century can be described as a “golden age” for plant exploration and collecting. During the initial years of this period, agricultural scientists from the United States and elsewhere devoted considerable resources to collecting potential new crops for farmers as well as superior plants or cultivars of the species that farmers were already growing. Over time, there was a shift toward collecting unadapted germplasm, or raw material that possessed traits that plant breeders and other scientists could use for cultivar improvement and other types of research. Although many institutions and individuals were involved in plant collecting during this period, the creation of the U.S. Department of Agriculture (USDA) Office of Seed and Plant Introduction in 1898, resulted in the largest single program devoted to plant exploration. This office employed many individuals, including David Fairchild, P.H. Dorsett, Frank Meyer, Walter Swingle, and Wilson Popenoe. These and many other individuals collected—and introduced into the United States—seeds and plants of thousands of fruits, vegetables, nuts, ornamentals, cereals, forages, oilseeds, and other types of crops. Although the mission of most of the plant explorations during this period was to collect any plants that appeared interesting or potentially useful, others focused on collecting targeted species. Much of the material collected during this era is still maintained by the U.S. National Plant Germplasm System (NPGS), and much more of it shows up in the pedigrees of cultivars grown by farmers and gardeners today. In addition to collecting plants for immediate and future use, scientists of this era, such as Nicolai I. Vavilov and Jack Harlan, contributed greatly to the understanding of the evolution of plants and plant genetic diversity, and the interdependence of plants and civilization.