Breeding and Development of New Nursery Crops

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
201	2110	1080	75%
206	2110	1020	25%

Progress 10/01/05 to 09/30/10

Outputs
OUTPUTS: Plant evaluation, selection, and improvement projects have been completed that identified and developed new nursery crops with enhanced pest resistance, greater tolerance to environmental stresses, and improved commercial potential. Breeding projects included work on Calycanthus, Cornus, Franklinia, Hydrangea, Magnolia, Mahonia, Pyrus, Rhododendron, Rudbeckia , and Viburnum. New crop introductions have included mountain hydrangea (Hydrangea arborescens 'NCHA1' Invincibelle Spirit), flowering quince (Chaenomeles speciosa) with red ('Scarlet Storm'), pink ('Pink Storm'), and orange ('Orange Storm') flowers, summersweet (Clethra alnifolia 'Crystalina'), pearlbush (Exochorda 'Blizzard'), and weigela (Weigela florida 'Sunset'). New hybrids and breeding lines will provide a foundation for future work and cultivar introduction. Additional projects are focusing on developing seedless, non-invasive cultivars of important nursery and biofuel crops including Acer platanoides, Acer tataricum, Berberis spp., Euonymus alatus, Elaeagnus spp., Hypericum androsemum, Ligustrum spp., Pyrus spp., Spiraea japonica, Campsis spp., and Miscanthus sinensis. Triploid hybrids of Elaeagnus spp., Hypericum androsemum, Spiraea japonica, Ligustrum spp. Pyrus spp., Campsis spp., and Miscanthus sinensis have been developed and will provide a basis for the future introduction of seedless cultivars. New seedless, noninvasive tutsan (Hypericum androseamum 'Pollock', 'Matisse', and 'Picasso') have also been released. To complement and facilitate these efforts, related projects have been completed to develop new technologies and understand reproductive biology, cytogenetics, heritability of traits, pest resistance, and tolerance to environmental stresses. Graduate students Jeff Jones, Lis Meyer, Clara Trueblood, Cary Hebert, Kevin Parris, Kelly Oates, Irene Palmer, and Jason Lattier students have been actively involved in many of these projects. Outreach activities, including talks, presentations, posters, and papers at conferences, symposia, field days, and tours, are delivered regularly to disseminate research findings. PARTICIPANTS: Individuals: Dr. Darren Touchell, NCSU, Cooperator; Tom Eaker, NCSU, Research Specialist; Nathan Lynch, NCSU, Research Specialist; Joel Mowrey, NCSU, Research Specialist; Jeremy Smith, NCSU, Research Specialist. Partner Organizations: North Carolina Biotechnology Center, Biofuels Center of North Carolina, Spring Meadow Nursery, Carolina Nurseries, J. Frank Schmidt Family Foundation, American Nursery and Landscape Association, North Carolina Nursery and Landscape Association, Clemson University, and USDA Floral and Nursery Crops Research Initiative. Training or Professional Development: Jeff Jones, M.S. Graduate Student; Lis Meyer, MS Graduate Student; Clara Trueblood, MS Graduate Student; Cary Hebert, MS Graduate Student; Kevin Parris, current MS Graduate Student with Clemson University; Irene Palmer, MS Graduate Student; Kelly Oates, MS Graduate Student, Jason Lattier, MS Graduate Student. TARGET AUDIENCES: TARGET AUDIENCES: Target Audiences: commercial nursery crop producers, landscape contractors, landscape architects and designers, general population, home gardeners, plant breeders, and other plant scientists. Outreach efforts, including talks, presentations, posters, and papers at conferences, symposia, field days, and tours, are delivered regularly to these groups. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This research provides valuable information on disease resistance and environmental stress tolerance of a wide range of commercially important landscape plants. Evaluation, selection, and improvement of cultivars with superior adaptability and reduced weediness will contribute to lower production costs, reduced need for pesticides, improved environmental quality, and superior agricultural products. Research was completed and published that determined the ploidy levels and relative DNA contents (genome sizes) of selected species and cultivars of rhododendron, rudbeckia, magnolia, mahonia, fothergilla, and barberries. This research provides a valuable information resource for plant breeders and will help facilitate the systematic development of improved hybrids. Research on reproductive biology was completed to evaluate the effect of increased ploidy levels on fertility in auto and allopolyploids, fertility of triploids, and the formation of unreduced gametes and aneuploids. This research provides plant breeders with information to better incorporate and utilize polyploids in plant improvement programs. Additional studies were completed on evaluating and developing new grass hybrids for biofuel applications, vegetative propagation methods of important crops, germplasm screening for resistance to the pathogen Phytopthora cinnamomi, development of an assessment system for evaluating potentially invasive species in North Carolina, micro propagation, breeding, and polyploid induction. These projects further contribute to the development and commercialization of new and superior crops.

Publications

Haines, S.A., R.J. Gehl, T.G. Ranney, and J.L. Havlin. 2010. Response of Miscanthus x giganteus to phosphorus and nitrogen fertilizer on low phosphorus soils in North Carolina. Soil Science Society of North Carolina 53rd Annual Meeting. Raleigh, NC. 19-20 January 2010. (poster).
Haines, S.A., R.J. Gehl, T.G. Ranney, and J.L. Havlin. 2010. Response of Miscanthus x giganteus to phosphorus and nitrogen fertilizer on low phosphorus soils in North Carolina. Soil Sci. Soc. of North Carolina 53rd Annu. Meeting. Raleigh, NC. 19-20 January 2010. (poster).
Ranney, T.G. 2010. Storm warning: Reinventing flowering quince. Nursery Notes 44(3):36-37.
Hebert, C.J., D.H. Touchell, T.G. Ranney, and A.V. LeBude. 2010. In vitro shoot regeneration and polyploidy induction of Rhododendron 'Fragrantissimum Improved'. HortScience 45(4):801-804.
Jones, J.R., A.V. LeBude, and T.G. Ranney. 2010. Vegetative propagation of Oconee azalea (Rhododendron flammeum) by stem cuttings and mound layering. J. Environ. Hort. 28(2):69-73.
Trueblood, C.E., T.G. Ranney, N.P. Lynch, J.C. Neal, and R.T. Olsen. 2010. Evaluating fertility of triploid clones of Hypericum androsaemum L. for use as non-invasive landscape plants. Hortscience 45(7):1026-1028.
Rounsaville, T.J. and T.G. Ranney. 2010. Ploidy levels and genome sizes of Berberis L. and Mahonia Nutt. species, hybrids, and cultivars. Hortscience 45(7):1029-1033.
Parris, J.K., T.G. Ranney, H.T. Knap, and W.V. Baird. 2010. Ploidy levels, relative genome sizes, and base pair composition in magnolia. J. Amer. Soc. Hort. Sci. 135(6):533-547.
Ranney, T.G. 2010. A few new plants. Nursery Notes 44(6):13-17.

Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: Plant evaluation, selection, and improvement projects are underway to identify and develop new nursery crops with enhanced pest resistance, greater tolerance to environmental stresses, and improved commercial potential. Breeding projects include work on Calycanthus, Cornus, Franklinia, Hydrangea, Magnolia, Mahonia, Pyrus, Rhododendron, Rudbeckia , and Viburnum. A new, continuous-blooming, pink-flowering, mophead, mountain hydrangea (Hydrangea arborescens 'NCHA1' Invincibelle Spirit) was introduced and is now being grown throughout the U.S. A series of new double-flowered, thornless, fruitless, flowering quince (Chaenomeles speciosa) with red ('Scarlet Storm'), pink ('Pink Storm'), and orange ('Orange Storm') flowers were developed, patents applied for, and released. Clethra alnifolia 'Crystalina', a compact, floriferous, summersweet was developed, patent applied for, and released. New hybrids have been developed from controlled pollinations and will provide a foundation for future work and cultivar introduction. Additional projects are focusing on developing seedless, non-invasive cultivars of important nursery and biofuel crops including Acer platanoides, Acer tataricum, Berberis spp., Euonymus alatus, Elaeagnus spp., Hypericum androsemum, Ligustrum spp., Pyrus spp., Spiraea japonica, Campsis spp., and Miscanthus sinensis. Triploid hybrids of Elaeagnus spp., Hypericum androsemum, Spiraea japonica, Ligustrum spp. Pyrus spp., Campsis spp., and Miscanthus sinensis have been developed and are under evaluation for fertility and commercial merit. Other breeding projects are progressing with over 5 acres of hybrids currently under evaluation. To compliment and facilitate these efforts, related projects are underway to develop new technologies and understand reproductive biology, cytogenetics, heritability of traits, pest resistance, and tolerance to environmental stresses. Graduate students (Lis Meyer, Clara Englert, Cary Hebert, Kevin Parris, and Kelly Oates) and interns (Irene Palmer and Jason Lattier) students have been actively involved in these projects. Outreach activities, including talks, presentations, posters, and papers at conferences, symposia, field days, and tours, are delivered regularly to disseminate research findings. PARTICIPANTS: Individuals: Dr. Darren Touchell, NCSU, Cooperator; Tom Eaker, NCSU, Research Specialist; Nathan Lynch, NCSU, Research Specialist; Joel Mowrey, NCSU, Research Specialist; Jeremy Smith, NCSU, Research Specialist. Partner Organizations: North Carolina Biotechnology Center, Biofuels Center of North Carolina, Spring Meadow Nursery, Carolina Nurseries, J. Frank Schmidt Family Foundation, American Nursery and Landscape Association, North Carolina Nursery and Landscape Association, Clemson University, and USDA. Training or Professional Development: Lis Meyer, MS Graduate Student; Clara Englert, MS Graduate Student; Cary Hebert, MS Graduate Student; Kevin Parris, current MS Graduate Student with Clemson University; Irene Palmer, research intern; Jason Lattier, research intern. TARGET AUDIENCES: Target Audiences: commercial nursery crop producers, landscape contractors, landscape architects and designers, general population, home gardeners, plant breeders, and other plant scientists. Outreach efforts, including talks, presentations, posters, and papers at conferences, symposia, field days, and tours, are delivered regularly to these groups. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This research provides valuable information on disease resistance and environmental stress tolerance of a wide range of commercially important landscape plants. Evaluation, selection, and improvement of cultivars with superior adaptability and reduced weediness will contribute to lower production costs, reduced need for pesticides, improved environmental quality, and superior agricultural products. Research was completed and published that determined the ploidy levels and relative DNA contents (genome sizes) of selected species and cultivars of Rudbeckia; evaluated self-compatibility and crossability among species; and determined ploidy levels, and reproductive pathways in triploid R. hirta. This research provides a valuable information resource for plant breeders and will help facilitate the systematic development of improved hybrids. Research on reproductive biology of Rhododendron was completed to evaluate the effect of increased ploidy level on fertility and evaluate pollen fertility of naturally occurring triploids found in the genus. The influence of polyploidy on fertility was influenced by the ploidy level, degree of homology among chromosomes, and in the case of triploids, the frequency of unreduced gamete formation. This research provides plant breeders with information to better incorporate and utilize polyploids in plant improvement programs. Work was completed to evaluate a collection of Gordonieae taxa for resistance to the pathogen Phytopthora cinnamomi. Results showed that sources of resistance to this disease exist in the tribe Gordonieae and that resistance can be successfully transmitted to hybrid progeny. This information will aid ongoing breeding efforts to combine the desirable ornamental traits of these taxa with a high level of resistance to P. cinnamomi. Additional studies are in progress including developing new grass hybrids for biofuel applications, vegetative propagation of deciduous azaleas, determining ploidy levels and genome sizes of Magnolia and Mahonia taxa, developing an assessment system for evaluating potentially invasive species in NC, micro propagation, breeding, and polyploid induction of Hypericum, Rudbeckia, Miscanthus, and Rhododendron.

Publications

Palmer, I.E., Ranney, T.G., Lynch, N.P., and Bir, R.E. 2009. Crossability, cytogenetics, and reproductive pathways in Rudbeckia subgenus Rudbeckia. Hortscience 44(1):44-48.
Jones, J.R. and Ranney, T.G. 2009. Fertility of neoppolyploid Rhododendron and occurrence of unreduced gametes in triploid cultivars. J. Amer. Rhododendron Soc. 63(3):131-135.
Meyer, E.M., Ranney, T.G., and Eaker, T.A. 2009. Differential resistance of Gordonieae trees to Phytophthora cinnamomi. HortScience 44(5):1484-1486.
Meyer, E.M., LeBude, A.V., and Ranney, T.G. 2009. Vegetative propagation of Gordonieae trees by stem cuttings. J. Envoron. Hort. 27(4):191-194.
Meyer, E.M., Touchell, D.H., and Ranney, T.G. 2009. In vitro shoot regeneration and polyploid induction from leaves of Hypericum species. HortScience 44(7):1957-1961.
LeBude, A.V. and Ranney, T.G. 2009. Evaluating landscape adaptability of hemlock species (Tsuga spp.) in Western North Carolina. Confer Quarterly 26(2):28-30.
Parris, J.K., Ranney, T.G., Baird, W.V., and Knap, H.T. 2009. Ploidy levels and genome sizes of Magnolia L. species, hybrids, and cultivars. Proc. SNA Res. Conf., 54th Annu. Rpt. 54:374-378.
Hebert, C.J., Touchell, D.H., Ranney, T.G., and LeBude, A.V. 2009. In vitro regeneration of Rhododendron 'Fragrantissimum Improved'. Proc. SNA Res. Conf., 54th Annu. Rpt. 54:460-463.
Meyer, E.M., Touchell, D.H., and Ranney, T.G. 2009. In vitro shoot regeneration from leaves of Hypericum sp. Proc. SNA Res. Conf., 54th Annu. Rpt. 54:464-468.

Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: Plant evaluation, selection, and improvement projects are underway to identify and develop new nursery crops with enhanced pest resistance, greater tolerance to environmental stresses, and improved commercial potential. Breeding projects include work on Calycanthus, Cornus, Franklinia, Pyrus, Viburnum, Mahonia, Rhododendron, and Rudbeckia. New hybrids have been developed from controlled pollinations and will provide a foundation for future work and cultivar introduction. Additional projects are focusing on developing seedless, non-invasive cultivars of important nursery and biofuel crops including Berberis spp., Euonymus alatus, Elaeagnus spp., Hypericum androsemum, Ligustrum spp., Pyrus spp., Spiraea japonica, Campsis spp., and Miscanthus sinensis. To compliment and facilitate these efforts, related projects are underway to understand reproductive biology, cytogenetics, heritability of traits, pest resistance, and tolerance to environmental stresses. Graduate (Jeff Jones, Lis Meyer, Clara Englert, Cary Hebert, and Kevin Parris) and undergraduate (Irene Palmer) students have been actively involved in these projects. Outreach activities, including talks, presentations, posters, and papers at conferences, symposia, field days, and tours, are delivered regularly to disseminate research findings. PARTICIPANTS: Individuals: Dr. Darren Touchell, NCSU, Cooperator Tom Eaker, NCSU, Research Specialist Nathan Lynch, NCSU, Research Specialist Joel Mowrey, NCSU, Research Specialist Jeremy Smith, NCSU, Research Specialist Partner Organizations: North Carolina Biotechnology Center Spring Meadow Nursery Carolina Nurseries J. Frank Schmidt Family Foundation Horticultural Research Institute American Nursery and Landscape Association North Carolina Nursery and Landscape Association Clemson University Training or Professional Development: Jeff Jones, MS Graduate Student, completed in 2008 Lis Meyer, current MS Graduate Student Clara Englert, current MS Graduate Student Cary Hebert, current MS Graduate Student Kevin Parris, current MS Graduate Student, with Clemson University Irene Palmer, undergraduate student TARGET AUDIENCES: Target Audiances: commercial nursery crop producers, landscape contractors, landscape architects and designers, general population and home gardeners. Outreach efforts, including talks, presentations, posters, and papers at conferences, symposia, field days, and tours, are delivered regularly to these groups. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
A new continuous blooming, pink-flowering, smooth hydrangea (Hydrangea arborescens 'Spirit') was developed, patent applied for, and released. Work on developing non-invasive nursery crops is progressing rapidly and triploid hybrids of Elaeagnus spp., Hypericum androsemum, Spiraea japonica, Ligustrum spp. Pyrus spp., Campsis spp., and Miscanthus sinensis have been developed and are under evaluation for fertility and commercial merit. Other breeding projects are progressing with over 5 acres of hybrids currently under evaluation. This research provides important information on the disease resistance and environmental stress tolerance of a wide range of commercially important landscape plants. Evaluation, selection, and improvement of cultivars with superior adaptability and reduced weediness will contribute to lower production costs, reduced need for pesticides, improved environmental quality, and superior agricultural products. A new species of deciduous azalea, Rhododendron colemanii (Red Hills azalea), from the upper Coastal Plain of Alabama and Western Georgia, USA, was characterized based on morphology, flowering phenology, habitat, native range, position in a molecular phylogeny, and genome size. Though specimens have previously been confused with Rhododendron alabamense or its hybrids, phylogenetic relationships based on sequences of the nuclear gene RPB2-I gene showed R. colemanii to be a coherent species in a clade of section Pentanthera along with R. luteum and the Southeastern U.S. azaleas R. atlanticum, R. austrinum, and R. calendulaceum. Flow cytometry showed R. colemanii to be, like the other azaleas in this clade, tetraploid. A detailed morphological description and Latin diagnosis was provided. A study was completed and published presenting ex-vitro method for inducing polyploidy in Rhododendron seedlings whereby repeated treatments of an oryzalin suspension in a warm agar solution was applied directly to apical shoots of young seedlings. Results demonstrated that this was an effective method for inducing polyploidy. Although single applications resulted in some polyploid plants, multiple applications increased efficacy for some of the taxa studied. Additional studies are in progress including: developing new grass hybrids for biofuel applications, vegetative propagation of deciduous azaleas and Gordonieae trees, study of reproductive biology of polyploidy rhododendron, determining ploidy levels and genome sizes of Magnolia and Mahonia taxa, evaluating landscape adaptability of hemlock species, developing an assessment system for evaluating potentially invasive species in NC, micro propagation and polyploid induction of Hypericum, Rudbeckia, Miscanthus, and Rhododendron.

Publications

Zhou, W., Gibbons, T., Goetsch, L., Hall, B., Ranney, T.G., and Miller, R. 2008. Rhododendron colemanii: A new species of deciduous azalea (Rhododendron section Pentanthera; Ericaceae) from the Coastal Plain of Alabama and Georgia. J. Amer. Rhododendron Soc. 62(2):72-78.
Jones, J.R., Ranney, T.G., and Eaker, T.A. 2008. A novel method for inducing polyploidy in Rhododendron seedlings. J. Amer. Rhododendron Soc. 62(3):130-135.
Touchell, D., Smith, J., and Ranney, T.G. 2008. Novel Applications of Plant Tissue Culture. Proc. Combined Eastern and Western Region Inter. Plant Propagators' Soc. (in press).
Contreras, R.N. and Ranney, T.G. 2008. New opportunities for breeding fragrant rhododendrons. J. Amer. Rhododendron Soc. 62(4): 201-202.
LeBude, A.V. and Ranney, T.G. 2008. Evaluating landscape adaptability of hemlock species (Tsuga spp.) in Western North Carolina. Nursery Notes 42(1):53-55.
Englert, C., Neal, J., and Ranney, T. 2008. What do invasive plants have to do with your nursery Nursery Notes. 42(6): 44.
Bush, E., Dunwell, W., Ingram, D., Owings, A., Blythe, G., Klingaman, B., Fare, D., Pounders, C., Niemiera, A., Nowak, J., Robbins, J., Lindstrom, J., Ruter, J., Knox, G., Scheiber, M., LeBude, A., Ranney, T., Arnold, M. and West, T. 2008. A historical summary of plant material evaluations by SERA-IEG. Proc. SNA Res Conf., 53nd Annu. Rpt. 53: 154-156.
Jones, J.R. and Ranney, T.G. 2008. Fertility of neopolyploid Rhododendron and occurrence of unreduced gametes in triploid cultivars. Proc. SNA Res Conf., 53nd Annu. Rpt. 53:172-175.
Palmer, I.E., Touchell, D.H., and Ranney, T.G. 2008. In-vitro polyploid induction of Rudbeckia spp. Proc. SNA Res Conf., 53nd Annu. Rpt. 53:184-187.
Meyer, E.M., LeBude, A.V., and Ranney, T.G. 2008. Propagation of Gordonieae trees by hardwood stem cuttings. Proc. SNA Res Conf., 53nd Annu. Rpt. 53:204-207.
Jones, J.R., LeBude, A.V., and Ranney, T.G. 2008. Vegetative propagation of Oconee azalea (Rhododendron flammeum). Proc. SNA Res Conf., 53nd Annu. Rpt. 53:208-211.
Touchell, D., Smith, J., and Ranney, T.G. 2008. Organogenesis from Hypericum frondosum leaves. Proc. SNA Res Conf., 53nd Annu. Rpt. 53:220-223.

Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: Plant evaluation, selection, and improvement projects are underway to identify and develop new nursery crops with enhanced pest resistance, greater tolerance to environmental stresses, and improved commercial potential. Breeding projects include work on Calycanthus, Cornus, Franklinia, Pyrus, Viburnum, Mahonia, Rhododendron, and Rudbeckia. New hybrids have been developed from controlled pollinations and will provide a foundation for future work and cultivar introduction. Additional projects are focusing on developing seedless, non-invasive cultivars of important nursery crops including Berberis spp., Euonymus alatus, Elaeagnus spp., Ligustrum spp., Pyrus spp., Campsis spp., and Miscanthus sinensis. To compliment and facilitate these efforts, related projects are underway to understand reproductive biology, cytogenetics, heritability of traits, pest resistance, and tolerance to environmental stresses. PARTICIPANTS: Darren Touchell, Ph.D. Thomas Eaker Nathan Lynch Joel Mowrey Jeremy Smith Jeff Jones Lis Meyer Irene Palmer

Impacts
Triploid hybrids of Ligustrum spp. Pyrus spp., Campsis spp., and Miscanthus sinensis have been developed and are under evaluation. Research was completed to determine the ploidy level and relative genome size of a diverse collection of species, hybrids, and cultivars of rhododendron using flow cytometry and traditional cytology. Polyploidy was found to be common in the genus Rhododendron and was considerably more prevalent in the subgenus Pentanthera than previously known. Particularly noteworthy were the findings that R. occidentale includes both diploid and tetraploid individuals and that R. atlanticum and R. asutrinum are predominantly tetraploid species. A study was completed to develop and evaluate an ex-vitro method for inducing polyploidy in Rhododendron seedlings whereby repeated treatments of an oryzalin suspension in a warm agar solution was applied directly to apical shoots of young seedlings. Results demonstrated that this was an effective method for inducing polyploidy. Although single applications resulted in some polyploid plants, multiple applications increased efficacy for some of the taxa studied. Fothergilla is a valuable nursery crop; however, clear differentiation among F. gardenii, F. major, and potential hybrids can be difficult based solely on morphological characteristics. A combination of chromosome counts and DNA contents was used to clearly differentiate among F. gardenii (2n = 4x = 48), F. major (2n = 6x = 72), and hybrids (2n = 5x = 60). Fothergilla x intermedia Ranney and Fantz (hybrid fothergilla) is proposed as the name for these hybrids. The correct classification and nomenclature for 17 different taxa were also determined. Winged euonymus (Euonymus alatus), for example, has been found to naturalize over broad areas and habitats. A study was completed to evaluate and compare fertility of E. alatus 'Compactus' with E. alatus 'Odom' Little Moses (USPP# 13168), a cultivar that has been observed to have low fertility in field and production settings. Under our conditions, the cultivar 'Odom' had 2.6% of the fruit set and 22% of the germination rate of 'Compactus', corresponding to 0.6% of the total reproductive potential (a 99.4% reduction). Breeding projects are progressing with over 5 acres of hybrids currently under evaluation. This research provides important information on the disease resistance and environmental stress tolerance of a wide range of commercially important landscape plants. Evaluation, selection, and improvement of cultivars with superior adaptability and reduced weediness will contribute to lower production costs, reduced need for pesticides, improved environmental quality, and superior agricultural products.

Publications

Ranney, T.G., Lynch, N.P., Fantz, P.R., and Cappiello, P. 2007. Clarifying taxonomy and nomenclature of Fothergilla (Hamamelidaceae) cultivars and hybrids. HortScience 42(3):470-473.
Lasseigne, F.T., Warren, S.L., Blazich, F.A., and Ranney, T.G. 2007. Day/Night temperature influences growth and photosynthesis of cultivated Salvia taxa. J. Amer. Soc. Hort. Sci. 132(4):492-500.
Jones, J.R., Ranney, T.G., Lynch, N.P., and Krebs, S.L. 2007. Ploidy levels and relative genome sizes of diverse species, hybrids, and cultivars of rhododendron. J. Amer. Rhododendron Soc. 61(4):220-227.
Ranney, T.G., Eaker, T.A., and Mowrey, J.A. 2007. Assessing fertility among cultivars of winged euonymus. Proc. SNA Res Conf., 52nd Annu. Rpt. (in press).
Touchell, D., Smith, J., and Ranney, T. 2007. Inheritance of leaf variegations in Miscanthus. Proc. SNA Res Conf., 52nd Annu. Rpt. (in press).
Palmer, I.E., Ranney, T.G., Lynch, N.P., and Bir, R.E. 2007. Exploring crossability among Rudbeckia L. species. Proc. SNA Res Conf., 52nd Annu. Rpt. (in press).
Jones, J.R., Ranney, T.G., Lynch, N.P., and Krebs, S.L. 2007. Ploidy levels and genome sizes of diverse species, hybrids, and cultivars of rhododendron L. Proc. SNA Res Conf., 52nd Annu. Rpt. (in press).
Ranney, T.G., Lynch, N.P., Fantz, P.R., and Cappiello, P. 2007. Clarifying taxonomy and nomenclature of Fothergilla (Hamamelidaceae) cultivars and hybrids. Proc. SNA Res Conf., 52nd Annu. Rpt. (in press).
Ranney, T.G., Touchell, D.H., Eaker, T.A., Lynch, N.P., Mowrey, J.A., and Smith, J.C. 2007. Breeding non-invasive nursery crops. Proc. Southern Region Intern. Plant Propagators' Soc. (in press).
Jones, J.R., LeBude, A.V., Ranney, T.G., and Conner, J. 2007. Mound layering of Rhododendron flammeum (Michx.) Sargent (Oconee azalea). Proc. Eastern Region Intern. Plant Propagators' Soc. (in press).
Jones, J.R., Ranney, T.G., and Eaker, T.A. 2007. Inducing polyploidy in rhododendron seedlings. Proc. Southern Region Intern. Plant Propagators' Soc. (in press).
Contreras, R.N., Ranney, T.G., Milla-Lewis, S.R., and Yencho, G.C. 2007. Investigating parentage and hybridity of three azaleodendrons using AFLP analysis. HortScience 42(3):740-743.

Progress 10/01/05 to 09/30/06

Outputs
Plant evaluation, selection, and improvement projects are underway to identify and develop new nursery crops with enhanced pest resistance, greater tolerance to environmental stresses, and improved commercial potential. Breeding projects include work on Calycanthus, Cornus, Franklinia, Pyrus, Viburnum, Mahonia, and Rhododendron. New hybrids have been developed from controlled pollinations and will provide a foundation for future work and cultivar introduction. Additional projects are focusing on developing seedless, non-invasive cultivars of important nursery crops including Berberis spp., Euonymus alatus, Elaeagnus spp., Ligustrum spp., Pyrus spp., Campsis spp., and Miscanthus sinensis. Research on reproductive behavior of sterile azaleodendrons demonstrated that induced allotetraploids had restored male and female fertility allowing for advanced hybridization between deciduous azaleas and evergreen rhododendrons. AFLP markers were also used to investigate the parentage of an unusual azaleodendron hybrid, Fragrant Affinity, determining that it is an intersubgeneric hybrid between Rhododendron ponticum and a deciduous azalea. Studies investigating the heritability of variegated and purple leaf foliage types in Hypericum androsaemum was completed and demonstrated that that both are simple recessive traits at the diploid level and are not linked. Interploid hybridization has led to the development of sterile, non-invasive, triploid Hypericums with a range of desirable foliage traits including a combination of variegated and purple characteristics. Triploid hybrids of Ligustrum spp. Pyrus spp., Campsis spp., and Miscanthus sinensis have also been developed and are under evaluation. Controlled crosses between Franklinia alatamaha and Gordonia lasianthus resulted in intergeneric hybrids that were given the new scientific name: xGordlinia grandiflora. We successfully obtained hybrids from intergeneric crosses between Weigela and Diervilla and confirmed parentage using cleaved amplified polymorphic sequence analysis. Research has been initiated to determine the ploidy levels and genome sizes of a diverse collection of Rhododendron clones and cultivars and to investigate the breeding behavior of polyploidy rhododendron. Propagation studies have been initiated to develop propagation protocols for difficult to root deciduous azaleas. Breeding projects are progressing with over 5 acres of hybrids currently under evaluation.

Impacts
This research provides important information on the disease resistance and environmental stress tolerance of a wide range of commercially important landscape plants. Evaluation, selection, and improvement of cultivars with superior adaptability and reduced weediness will contribute to lower production costs, reduced need for pesticides, improved environmental quality, and superior agricultural products.

Publications

Ranney, T.G. and P.R. Fantz. 2006. xGordlinia grandiflora (Theaceae): An intergeneric hybrid between Franklinia alatamaha and Gordonia lasianthus. HortScience 41(6):1386-1388.
Ranney, T.G., D. Touchell, R. Olsen, T. Eaker, N. Lynch, and J. Mowrey. 2006. Progress in breeding non-invasive nursery crops. Pro. SNA Res. Conf., 51st Annu. Rpt.
Touchell, D., Z. Viloria, T. Ranney, and K. Ivors. 2006. Intergeneric hybrids between Weigela and Diervilla (Caprifoliaceae). Pro. SNA Res. Conf., 51st Annu. Rpt.