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During Dec. 1997 and Jan. 1998, the gooseberry mite, Cecidophyopsis grossulariae Collinge, was observed to infest 48 currant and gooseberry (Ribes L.) cultivars in a field plantation in Corvallis, Ore. The mite was observed on 29 black currant, (Ribes nigrum L.), two red currant [Ribes rubrum L. and R. sativum (Rchbch.) Syme], 12 gooseberry [R. uvacrispa L., R. oxyacanthoides var. setosum (Lindley) Sinnot], and three R. ×nidigrolaria Bauer cultivars and the hybrid R. nigrum × R. pauciflorum Turcz. ex Pojark. A range of mite infestation levels was observed, with some cultivars not being infested, some with light infestation, having 1 to 100 adult mites per bud, and some heavily infested, with more than 100 mites per bud. On lightly infested buds, the mites were inside bud and leaf scales; in heavily infested buds, mites were also observed on floral primordia. Scales of infested buds were often loose and appeared more open than noninfested ones. Mite distribution varied by branch within a plant. Black currant cultivars with the heaviest infestation of C. grossulariae were of Scandinavian, Russian, Scottish, and Canadian origin. The Russian black currant cultivar Tunnaja was the most heavily infested with more than 1000 mites per bud. Floral primordia were damaged in heavily infested buds.
Approximately 450 accessions representing 40 taxa from around the world, including 77 advanced breeder selections and 54 F1 hybrids are maintained at the repository in Corvallis. Most of the clones came from the collection of M. J. Murray of the A. M. Todd Company, Kalamazoo, MI. Others were received from the former USDA/ARS mint breeding program in Corvallis which ended in 1981. Data on origin, morphology, pedigree, oil analysis, fertility and chromosome number was provided with many of the accessions. We have confirmed the identity of the clones utilizing many of these features. We are actively seeking unrepresented germplasm. Chromosomes from pollen mother cells or root-tip cells are currently being counted. Nomenclature changes reflecting recent research have been made. Many clones have been indexed for viruses. Infected clones are treated with thermotherapy and meristem culture to produce virus-negative replacements. An in vitro backup collection is maintained in cold storage. Iniation of in vitro cultures has been complicated by internal bacterial contamination in some clones. Research to eliminate this problem is in progress. Cuttings and in vitro cultures of Mentha germplasm are available to researchers worldwide.
Asian germplasm has significantly contributed to berry crops in America in several ways. The American wild octoploid species [Fragaria chiloensis (L.) Mill. and F. virginiana Mill.], and subsequently, the cultivated strawberry (F. ×ananassa Duch. ex Rozier), have benefitted from Asian heritage in the evolutionary time scale. Second, breeders have combined Asian germplasm in crosses for improved fruit cultivars. Third, Asian temperate fruit species have been collected from wild stands in their native ranges, imported, and in some cases improved and are now cultivated in the West or throughout the world. The objectives of this article were to 1) describe evolutionary contributions of Asian species to the American strawberry genome; 2) present examples of breeding Asian species (Rubus L. subgenus Idaeobatus) into cultivated raspberries; and 3) give examples of two Asian fruit species that have been recently introduced and cultivated or that could be developed for cultivation in the United States.
The year 2005 marked the 25th anniversary of the establishment of the U.S. Department of Agriculture (USDA) National Plant Germplasm System (NPGS), repositories devoted to clonally propagated, horticultural fruit and nut crops. During this quarter century, facilities in Hilo, Hawaii; Mayaguez, PR.; Miami, Fla.; and Riverside, Calif. were developed to preserve collections of tropical and subtropical fruit and nut crops; facilities in Brownwood, Texas; Corvallis, Ore.; Davis, Calif. and Geneva, N.Y. preserve the temperate crops. Each of these facilities now has internationally recognized, globally diverse collections of genetic resources for their assigned genera. Germplasm of unique genotypes are maintained as growing plants, evaluated for phenotypic and genotypic traits, documented in a national public germplasm database, and freely distributed as clonal propaggules to researchers and other germplasm users around the world. Seed collections represent wild populations for some crop relatives. These 8 genebanks maintain 30,000 accessions representing 1600 species of fruit and nut crops and their wild relatives. The genebanks distribute more than 15,000 accessions annually to international researchers. Although originally conceived as working collections for crop improvement, NPGS genebanks have also become invaluable in providing the raw materials for basic plant genetic research, reservoirs for rare or endangered species or vulnerable landraces, archives of historic cultivars, and field classrooms for educating the public. These collections preserve botanical treasures as well as the American horticultural heritage for now and for future generations.
An elite group of 38 strawberry accessions representing all subspecies of the beach strawberry [Fragaria chiloensis (L.) Miller] and the scarlet strawberry (F. virginiana Miller) was planted in a replicated design at five locations across the United States, and evaluated for plant vigor, flowering date, runner density, fruit set, fruit appearance, and foliar disease resistance. Considerable genotyp× location interaction was observed for many of these traits. However, a few genotypes were impressive at all locations including PI 551735 (FRA 368) with its unusually large, early fruit, and PIs 612486 (NC 95-19-1), 612493 (Frederick 9), and 612499 (RH 30), which were very vigorous and had unusually good fruit color. Genotypes that were superior at individual locations included PIs 551527 (FRA 110) and 551728 (Pigeon Pt.) in Maryland for their large fruit, and PI 612490 (Scotts Creek) in Oregon which had extremely large fruit, superior color, firmness, and flavor. The PIs 612495 (LH 50-4), 612498 (RH 23), and 612499 (RH 30) performed well as day neutrals at multiple sites.