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The fruits of the earth have healed, nurtured, and intrigued humanity throughout history. Cultivated fruit species have complex genome that will continue to require the input of novel genetic resources. Prospecting for wild fruit species will continue. The global nature of science and commerce will drive the demand to expand available genetic resources for fruit improvement. New technologies will enable future explorers to reach remote sites and species. Recent advances, such as geopositioning and remote-communication devices, will be used to a greater degree for targeting specific collection sites and documenting records of origin. The sovereignty of countries over their plant genetic resources, as specified by the Convention on Biological Diversity and the International Treaty on Plant Genetic Resources for Food and Agriculture, will continue to be a cornerstone for negotiating bilateral agreements and plant exchange. Although this could be considered a limitation to plant exploration in some situations, global strategies now in conceptual infancy will be developed to encourage and support ex situ preservation and continued plant exchange for long-term conservation and humanitarian benefit.
Several species of Ribes have ornamental qualities worthy of consideration in residential and commercial temperate zone landscape plantings. Ribes sanguineum Pursh has been selected and cultivated throughout the Pacific Northwest, and boasts of early spring flowers of white, pink, or red. The two species of golden currants, R. aureum Pursh and R. odoratum Wendl. f., have brilliant yellow-fl owered racemes. Ribes species exhibit a broad diversity of plant habit and texture ranging from the upright 2.5 m, vigorous, and fully armed Menzieís Gooseberry, R. menziesii Pursh, to the prostrate shade-loving Crater Lake currant, R. erythrocarpum Coville & Leiberg. R. viburnifolium A. Gray remains evergreen in mild climates throughout the year. The foliage of some selections of R. americanum Miller and R. cynosbati L. brighten to a brilliant crimson red in the fall. The fall foliage of other species, such as R. hirsuta L., develop a continuum of color on their branches, from bright red at the apex, through orange and yellow to green towards the base. Spring bloom data and ratings of fall color for species in the Corvallis Repository collection will be described.
The center of diversity for white pine blister rust (WPBR) (Cronartium ribicola J.C. Fischer) most likely stretches from central Siberia east of the Ural Mountains to Asia, possibly bounded by the Himalayas to the south. The alternate hosts for WPBR, Asian five-needled pines (Pinus L.) and Ribes L. native to that region have developed WPBR resistance. Because the dispersal of C. ribicola to Europe and North America occurred within the last several hundred years, the North American five-needled white pines, Pinus subsections, Strobus and Parya, had no previous selection pressure to develop resistance. Establishment of WPBR in North American resulted when plants were transported both ways across the Atlantic Ocean. In 1705, Lord Weymouth had white pine (P. strobis L.), also called weymouth pine in Europe, seed and seedlings brought to England. These trees were planted throughout eastern Europe. In the mid-1800s, WPBR outbreaks were reported in Ribes and then in white pines in eastern Europe. The pathogen may have been brought to Europe on an infected pine from Russia. In the late 1800s American nurserymen, unaware of the European rust incidence, imported many infected white pine seedlings from France and Germany for reforestation efforts. By 1914, rust-infected white pine nursery stock was imported into Connecticut, Indiana, Massachusetts, Minnesota, New Hampshire, Ohio, Pennsylvania, Vermont, and Wisconsin, and in the Canadian provinces of Ontario, Quebec, and British Columbia. The range of WPBR is established in eastern North America and the Pacific Northwest. New infection sites in Nevada, South Dakota, New Mexico and Colorado have been observed during the 1990s.
More than 35 species of blueberries (Vaccinium L.) and huckleberries (Vaccinium and Gaylussacia Kunth.) are indigenous to North America. The indigenous North American peoples, wise in the ways of survival, recognized the quality of these edible fruits and revered these plants. Beyond food needs, these plants played significant roles in their culture, sociology, economics, and spirituality. Because these traditions, developed and gathered over millennia, were transmitted orally, documentation of these uses have been determined through archeological data, written records from western civilization after first contact, and recent surveys of present-day native peoples. The wealth of indigenous knowledge on blueberries, huckleberries, and other foods was shared with European immigrants. These fruits were used by many tribes throughout North America. Samuel de Champlain documented that fresh and dried blueberries provided “manna in winter” when other food was scarce. Pemmican, a preserved concoction of lean meat, fat, and blueberries or other fruit, enabled survival. Blueberry products such as ohentaqué, hahique, satar, sakisatar, sautauthig, k’enkash, navag, and nunasdlut’i were important to Native Americans. Roger Williams, Meriwether Lewis, and Henry David Thoreau were each impressed with the uses of blueberries by indigenous Americans. The social, technological, and horticultural changes that gave rise to a commercial wild huckleberry and blueberry gathering and production history are summarized.
In commercial growing regions the bloom period for currants and gooseberries is critical to crop development because of potentially damaging spring frosts. Breeding programs in northern latitudes include selection for frost avoidance mechanisms such as late blooming tendencies. Corvallis climate is milder than Ribes production regions, with the average winter minimum temperature about 10C and the coldest recorded April temperature of -5C in 1926. The last spring frost occurs by April 14 on average. About 30 cultivars and species selections of currants and about that same number of gooseberries were evaluated for blooming and fruiting at the National Clonal Germplasm Repository. Dates of first bloom, last bloom, first ripening, and last ripening during 1987 through 1989 were collected. The longest ripening period, 93 days, occurred in 1989 on a selection of R. burejense F. Schmidt. The shortest ripening period in 1989 was 70 days, occurring in many black currant cultivars including Black September, Crusader, Coronet, and Invigo. These same cultivars required a range from 62 to 66 days to ripen m 1987. For the years examined thus far, the earliest ripening dates occurred in 1987, starting as early as Julian date 150; the latest ripening date (192, Julian) occurred in 1988. Data from 1990 will be presented. The climate in the Pacific Northwest is favorable for the production of currants and gooseberries.
The U.S. Department of Agriculture (USDA), Agricultural Research Service, National Clonal Germplasm Repository in Corvallis was established as the U.S. National Plant Germplasm System's berry genebank in 1981. Since then, the USDA has sponsored numerous explorations throughout the United States and foreign countries to obtain berry plant genetic resources. Species of Fragaria L. (strawberries), Ribes L. (currants and gooseberries), Rubus L. (raspberries and blackberries), and Vaccinium L. (blueberries and cranberries) are native to both domestic and international localities. With limited gene pools for cultivated strawberries, raspberries, and blackberries, expeditions have provided a wealth of genetic resources to expand opportunities for breeders to develop new cultivars. Particularly given the diverse species inherent in the development of cultivated blueberries, these trips have discovered unusual new blueberry relatives and forms available for expanding the range of production, increasing plant yields, and improving fruit antioxidant content. Along the way, new fruit species and new uses for known species were observed. Gathering the bounty of the world's berries resulted in encounters with diverse fauna, from snakes, bears, and bison to butterflies, mosquitoes, ticks, and chiggers. Avenging Toxicodendron species have added their mark on intrepid explorers. Remote sites with nothing but clear night stars and the satellite markers on the global positioning system offer radiant beauty and an abiding hope for the conservation of plant genetic diversity for all people for all time.
We contrasted the effect of liquid nitrogen (LN2), sulfuric acid (H2SO4), and a nontreated control on the germination of six Rubus species. We also were interested in determining if LN2 could be an effective mechanical scarifying agent for these species. Seeds of each species were treated with three 3-minute dips in LN2 with alternating 10-minute thaws, with H2SO4 for 30 minutes, or left untreated. The percent germination of R. multibracteatus A. Leveille & Vaniot, R. parviflorus Nutt., R. eustephanos Focke ex Diels, R. leucodermis Douglas ex Torrey & A. Gray, R. ursinus Cham. & Schldl., and R. chamaemorus L. treated with LN2 was not significantly different than the control. Germinated seedlings from the LN2 treatment of each species showed normal development upon planting, indicating that long-term cryogenic preservation of these Rubus species seeds may be possible. The H2SO4 treatment significantly increased the rate and percentage of germination in R. parviflorus, R. eustephanos, R. leucodermis, and R. ursinus over that of the control and the LN2 treatment. The alternative LN2 application techniques that have been attempted thus far have not significantly improved Rubus seed germination compared with that of the control.
Black currant (Ribes nigrum L.) cultivars with heavy, light, and no gooseberry mite (Cecidophyopsis grossulariae Collinge) infestation levels (MIL) were tested for cold hardiness by visually determining the bud injury rating (BIR) after laboratory freezing in Jan. 1998. Lightly mite-infested cvs. Blackdown and Risager, usually thought of as less cold hardy than Nordic cultivars, survived -35 °C, while mite-infested buds of the Finnish cv. Brödtorp were injured at -35 °C. Heavily mite-infested buds of the Swedish R. nigrum L. cv. StorKlas from Corvallis, Ore., were injured at -20 °C while lightly infested buds were injured to -25 °C. Noninfested `StorKlas' buds from Pennsylvania and British Columbia survived laboratory freezing to -35 °C. Heavy mite infestation lowered the bud cold hardiness of `Brödtorp' and `StorKlas' by 10 °C, as estimated by a modified Spearman-Karber T50, relative to the hardiness of lightly mite-infested buds of these cultivars. Heavily mite-infested buds contained unusual tissues forming what appeared to be spherical blisters or eruptions, ≈100 μ in diameter. Other tissues in the region of heavy mite infestation appeared to be more turgid than their noninfested counterparts. Abiotic and biotic stresses can have a combined impact on field-grown black currants.
A plant-collecting expedition to Iturup and Sakhalin Islands, Sakhalin Territory, Russian Federation, occurred between 21 July and 12 Sept. 2003. Strawberries, Fragaria L., were observed and collected. Japanese and Russian flora describe two diploid (2n = 2x = 14) species, F. iinumae Makino and the Yezoensis strawberry, F. nipponica Makino [syn. = Fragaria nipponica var. yezoensis (H. Hara) Kitam.], as native to those islands. In addition, a recent monograph described a new octoploid (2n = 8x = 56) strawberry species, F. iturupensis Staudt, from a Japanese herbarium specimen collected on Atsunupuri volcano near Lesozovodoskyi, Iturup, in 1929. The objectives of the 2003 collecting trip were to obtain wild strawberries from these islands and determine if a population of F. iturupensis still existed on the volcano. The native F. iinumae Makino was obtained from the Ogonki Village, Anivskyi Region, Southern Sakhalin Island, but was not observed on Iturup. The Yezoensis strawberry was observed at Cape Otlivnoy, Iturup. Two small colonies of the native octoploid F. iturupensis Staudt were collected from mid-elevations on the east-facing slope of Atsunupuri volcano. The native distribution of F. iturupensis was limited to this volcanic montane habitat and was not found in the foggy, sandy locations of coastal elevations on Iturup. The leaf morphology and growth habit of F. iturupensis plants were similar to that of F. virginiana subsp. glauca (S. Watson) Staudt of North America, but the fruit was different, more like F. vesca L. Probable cultivated escapes were observed at two sites on the east coast of Iturup and at one site in southern Sakhalin. The 2003 expedition confirmed the existence of F. iturupensis, the only known native Asian octoploid strawberry on Atsunupuri. Limited quantities of germplasm are available for research from the curator, U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository, Corvallis, OR, the U.S. national strawberry gene bank.