Efforts have been underway since 1988 to establish a nursery research station in McMinnville, TN. Approximately 80 acres of farm property has been conveyed to Tennessee State University (TSU) for this purpose. Scientists at TSU, Tennessee Technological University, University of Tennessee, and USDA's National Arboretum and Shade Tree Laboratory have cooperated in obtaining funding via the Capacity Building Grants Program to initiate a plant evaluation and introduction program at the new station. Initial trials of woody genera include Acer, Castanea, Cornus, Lagerstroemia, Quercus, Syringa, and Ulmus. Herbaceous genera are Echinacea, Hemerocallis, and Hosta. Plantings will be made over a three year period as infrastructure at the new station develops. Complementary grant proposals have been recently submitted. Design, funding and support of all Tennessee introduction and evaluation programs will be discussed.
Surface morphology of peach [Prunus persica (L.) Batsch] Plant Introduction 133984 (`Marina') differs from standard peach and nectarine clones. Scanning electron microscopic examination of `Marina', a standard peach (`Contender'), and a nectarine (`Sunglo') was conducted. At anthesis, `Marina' ovaries were glabrous, similar to `sunglo' nectarine. Fruit of `Contender' were fully pubescent at anthesis. Examination of `Marina' fruit two weeks after anthesis revealed the presence of both pubescent and glabrous sectors on the fruit surface. At fruit maturity, most of the fruit surface of `Marina' was covered with pubescence, but trichome density was considerably less than `Contender' peach. Trichome morphology of `Marina' differed from that of `Contender'.
An historic feature of the JC Raulston Arboretum (JCRA) is to identify new and unusual ornamental plant materials for landscape use through an active program of observing landscape performance at the JCRA in Raleigh. Introduction of plant materials into commerce occurs primarily through programs conducted in concert with the North Carolina Association of Nurserymen and through a unique policy of “open access” for nurserymen. One program, The JC Raulston Selections Program, returns revenues to the general operations and maintenance functions of the JCRA; others are not revenue generating, and are provided as a service to the industry. To a lesser extent, the general public may participate in receiving new plants via a special program offered through JCRA membership. The JCRA is also an official trial garden site for the All America Selections program and seed companies. Elements of these introduction and evaluation programs will be discussed within the context of the past, present, and plans for the future for program maintenance and possible changes.
The sweetpotato weevil is the most-destructive worldwide pest of sweetpotato and only low to moderate levels of resistance to the insect are available in acceptable cultivars. No sources of high resistance levels have been identified; consequently, there is a need to identify additional sources of resistance genes to develop high resistance levels. To begin a search for sources of resistance, plant introductions were evaluated for injury levels. In 1993, 100 plant introductions were evaluated for sweetpotato weevil injury and 62 of the least injured were tested again in 1994. In 1995, 36 of the least injured in 1993 and 1994, plus 24 additional PIs were evaluated. Control cultivars included `Regal', moderately resistant; `Jewel', intermediate; and `Beauregard' and `Centennial', susceptible. Measurements of injury were percentage of roots injured, and, stem and root injury scores based on a 0–5 scale, with 0 being no injury. First year results indicated that a low level of resistance to stem injury is available in the PIs tested. Stem injury was more severe in the following year and no differences were found. Lower weevil populations will be required to screen for low levels of stem injury resistance. Percentage injured roots and root injury scores were lower over the 3 years for five PIs than for `Regal'.
Since 1988, efforts have been underway to establish a nursery research station in McMinnville, Warren County, Tennessee. Approximately 80 acres of farm property adjacent to the Collins scenic river has been conveyed to Tennessee State University (TSU) for this purpose. Scientists at TSU, Tennessee Technological University, University of Tennessee, and USDA's National Arboretum and Shade Tree Laboratory have cooperated in obtaining grant funds via the Capacity Building Grants Program to initiate a plant evaluation and introduction program. Replicated trials of woody genera include Acer, Castanea, Cornus, Lagerstroemia, Quercus, Syringa, Ulmus. Herbaceous genera are Echinacea, Hemerocallis, Hosta. Plantings will be made over a three year period as infrastructure at the new station develops. Additional grant proposals have been recently submitted.
Abstract
During the 1984 growing season, 156 peach and 40 nectarine cultivars, 49 plant introductions, and 33 Prunus species or species hybrids were evaluated for susceptibility to bacterial spot [Xanthomonas campestris pv. pruni (Smith 1903) Dye 1978] in North Carolina and South Carolina. Fruit and leaf infection and percentage of defoliation were evaluated in North Carolina, while only leaf infection data were evaluated in South Carolina. No cultivar was immune, but susceptibility varied greatly. Based on leaf infection in the 2 locations, it was concluded that disease pressure was greater in North Carolina. Correlation of fruit infection severity with leaf infection severity and percentage of defoliation in North Carolina was r = 0.30 (P = 0.01) and r = 0.54 (P < 0.01), respectively. Correlation between leaf infection severity and percent defoliation was r = 0.51 (P < 0.01) and r = 0.00 (NS) in North and South Carolina, respectively.
The Horticulture Program at the Western Regional Plant Introduction Station is responsible for the maintenance and distribution of germplasm collections of ten crop genera. These ten genera include over 28,000 accessions of 267 species of germplasm with either food or ornamental potential. The largest collection is beans (Phaseolus, > 11,500 accessions) which includes 32 species. Large collections of the cool season food legumes include Cicer, Pisum and Lens. Smaller legume collections include Lupinus, Lathyrus, Trigonella and Vicia. Although there are fewer than 3300 accessions within these four genera, there are 134 species represented. Although smaller in number of accessions, the Allium and Lactuca collections are extensively utilized for food and ornamental development programs. Associated with the curation and seed maintenance of these crops is a seed-borne virus eradication program, the development of core collections, and expansion of the evaluation data and other documentation into the Germplasm Resources Information Network.
his most famous plant discovery—the famous potato that bears his name, which incredibly was derived from 23 seeds and 15 seedlings of open-pollination of an introduction known as ‘Early Rose’. This discovery and impact were treated in a presentation by
In 1991, the USDA–ARS North Central Regional Plant Introduction Station made available for distribution 129 accessions of germplasm representing 31 genera of herbaceous ornamentals. This number increased to 329 accessions of 42 genera by 1995. During 1991–95, more than 500 seed packets were distributed to fulfill requests for these plants received from a diverse array of public and private researchers. An analysis of this demand together with expert advice from Crop Germplasm Committees and technical considerations, such as ease of culture and seed production, can help set priorities to plan germplasm regeneration to meet future demand. A recent analysis of demand at U.S. National Plant Germplasm System active sites indicated that demand ranging between 0.23 and 0.97 distributions per available accession per year was typical. Of the 42 ornamental genera analyzed in this study, 9 were demanded more frequently than was typical, 10 were demanded less frequently, with the remainder in the typical range. In order of increasing frequency, the nine genera with the highest distribution rates were Verbena, Gypsophila, Echinacea, Lapeirousia, Delphinium, Cerastium, Baptisia, Lilium, and Tanacetum. Six of these genera are represented only by a single available accession. Notably, Echinacea and Tanacetum are of research interest both as ornamentals and as medicinal/industrial crops. This poster gives a brief overview of the economic value of these genera, display the results of the demand analysis, discuss the results relative to recommendations from Crop Germplasm Committees and requestors, and consider how demand can shape management plans for the acquisition and regeneration of ornamental germplasm.
information contained in this document: Bruce Mowrey, for his contributions to the isozyme genetics of the peach plant introductions, and for data on male sterility and gland types; Jose Chaparro, for recognizing and documenting the unique anthocyanin