Source: UNIVERSITY OF FLORIDA submitted to NRP
BREEDING LOW-MAINTENANCE AND NON-INVASIVE ORNAMENTAL PLANTS FOR LANDSCAPE AND CONTAINER USE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0217196
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2008
Project End Date
Sep 30, 2013
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611
Performing Department
Environmental Horticulture
Non Technical Summary
Florida is the second largest producer of ornamental plants in the U.S. with an estimated $15.2 billion dollar total industry sales during 2005. A continued expansion of the floriculture industry requires development and introduction of new crops, as well as improved cultivars of existing crops. With increasing restrictions on water use in the landscape and the decrease in active gardening as a pastime, it is important to develop and select plants that require low-maintenance (have low water and fertilizer requirements, few pests and disease problems, controlled growth habit, good performance under a range of light conditions, and are non-invasive). We have identified several plants that have had excellent performance during the past two years at the UF Trial Garden in Gainesville, but are currently underutilized, such as Pseuderanthemum, Graptophyllum, Strobilanthes, Sanchezia, Alternanthera, Crossandra and Justicia. Our aim is to develop new hybrids and mutants with potential as new cultivars by using a) classical breeding using artificial hybridizations; b) mutation breeding using irradiation. New hybrids or mutant plants obtained will be evaluated for overall performance under three different watering regimes during summer. Selected plants will then be trialed by private companies in other regions of the U.S. for potential release as new cultivars. Another focus of this breeding program is Ruellia. The most common species used is R. brittoniana (Mexican petunia), however it is considered an invasive species. Consequently, there is demand cultivars with different flower colors that are sterile and non-invasive. Sterilization of Ruellia will be pursued using mutation breeding and hybridization between plants with different numbers of chromosome sets. It is also important to assess whether R. brittoniana can naturally hybridize with the Florida native R. caroliniensis and therefore negatively affect the native plant populations. This will be determined by performing artificial hybridizations between plants of the two species and studying the hybrids obtained.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2012120108110%
2012122108110%
2012123108115%
2022120108115%
2022122108115%
2022123108120%
2022199108115%
Knowledge Area
202 - Plant Genetic Resources; 201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
2199 - Ornamentals and turf, general/other; 2123 - Bedding/garden plants; 2120 - Herbaceous perennials and decorative greens; 2122 - Potted plants;

Field Of Science
1081 - Breeding;
Goals / Objectives
Objectives are (1) To breed low-maintenance and drought tolerant ornamental plants for landscape or container use. (2) To breed sterile, non-invasive plants of Ruellia brittoniana (Mexican Petunia) in a range of flower colors, and to assess the compatibility between Ruellia species including the Florida native R. caroliniensis.
Project Methods
For the first objective, several foliage bedding plants have been selected such as Pseuderanthemum, Graptophyllum, Strobilanthes, Sanchezia, Alternanthera and Iresine, and flowering herbaceous plants such as Crossandra and Justicia. Collections of species or named cultivars for these genera have been compiled. Both classical and mutation breeding methods will be used. New hybrid progenies or selected mutant plants will be propagated vegetatively and evaluated in the summer under full sun in Citra, FL, using three replicates per treatment under three watering regimes. Plants will be evaluated every 2 weeks on a scale of 0-5 for overall performance. Selections will be based on overall performance, lack or low incidence of diseases and pests, and controlled growth habit. Selected breeding lines will be available to interested floriculture companies for potential release as new cultivars. Evaluation of herbaceous perennials or woody landscape plants will also be performed to select genera for long-term breeding research. For the second objective, to breed sterile, non-invasive plants of Ruellia brittoniana (Mexican Petunia) we will use: a) artificial hybridizations and wide crosses between divergent species; b) mutation breeding using irradiation; and c) ploidy manipulations using both in vitro and in vivo techniques. Breeding lines that do not set fruit in the greenhouse will be evaluated during summer for seed production in the landscape. Compatibility between native R. caroliniensis and invasive R. brittoniana will be assessed by performing manual hybridizations between three genotypes for each species. F1 progenies will be grown in the greenhouse and evaluated for intermediate morphology and fertility.

Progress 10/01/08 to 09/30/13

Outputs
Target Audience: Commercial ornamental growers and land managers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Three undergraduate part-time employees were trained in plant breeding techniques and greenhouse management. How have the results been disseminated to communities of interest? Peer-reviewed journals, popular journals, presentations in conferences, information in appropriate websites. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? TwoPseuderanthemum hybrids and two mutants, one Hemigraphis mutant and three Ruellia interspecific hybrids continue to be incommercial trials for potential cultivar release. Ruellia 'Mayan Purple' and 'Mayan White' were released in 2012 and 'Mayan Pink' in 2013. These cultivars are sterile and non-invasive andwere approved for released by the UF/IFAS Invasive Plants Task Force. Theyhave beenlicensed to an ornamental company and have been available for sale. The patent for 'Mayan Purple' has been approved, and the other two are in process. To explore the hybridization potential between the invasive plant species Ruellia simplex and the closely related, sympatric Ruellia caroliniensis, we conducted a study of reproductive crossability and hybrid viability. Results indicate that the production of interspecific hybrids is possible, but only in one direction (i.e., with R. caroliniensis as the maternal parent). Artificial hybrids were weak, slow growing, and sterile. These data suggest that it is unlikely that R. caroliniensis x R. simplex hybrids could invade the gene pool of native R. caroliniensis.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Wilson, S.B., G.W. Knox, R. Freyre, and Z. Deng. Characterizing the invasive potential of ornamental plants. 2012 Proc. XXVIII International Horticulture Congress on Science and Horticulture for People. Acta Hort. 937:1183-1192.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Czarnecki II, D.M., S.B. Wilson, G.W. Knox, R. Freyre, and Z. Deng. 2012. UF-T3 and UF-T4  Two sterile Lantana camara cultivars. HortSci. 47:132-137.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Freyre, R., A. Moseley, S.B. Wilson and G.W. Knox. 2012. Breeding and evaluating for landscape performance and fruitlessness in Mexican petunia. HortSci. 47:1245-1251.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Freyre, R., A. Moseley, S.B. Wilson and G.W. Knox. 2012. Fruitless Ruellia simplex R10-102 ('Mayan Purple') and R10-108 ('Mayan White'). HortSci. 47:1808-1814.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Freyre R., A. Moseley, C. Reinhardt-Adams, A.G.W. Knox, S.B. Wilson and Z. Deng. 2013. Breeding Ruellia spp. at the University of Florida. Proc. VIIth International Symposium on New Floricultural Crops. Eds.: G. Facciuto and M.I. Sanchez. Acta Hort. 1000, pp. 423-428.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Freyre, R., S.B. Wilson and G.W. Knox. 2013. Breeding Ruellia and trialing for sterility at the University of Florida. Proc. 2013 International Plant Propagators Soc.  Southern USA Region.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Freyre, R. 2013. Ruellia: New colors and non-invasive cultivars for an outstanding landscape plant. OFA publication. December 2013.
  • Type: Websites Status: Other Year Published: 2013 Citation: Freyre, R. C. Reinhardt-Adams and S.B. Wilson. 2013. Mexican Petunia, Ruellia simplex. UF/IFAS Center for Aquatic and Invasive Plants website.


Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: Ornamental foliage plants obtained from mutation breeding were selected after field or greenhouse trials in 2010. For some time a company in California indicated they had interest in commercializing three of our selections, which were derived from a plant named commercially as Perilla. We conducted a thorough taxonomical evaluation, which concluded that these lines were actually Plectranthus scutellarioides (Coleus) and not Perilla. Landscape performance evaluation of these three Coleus selections was performed in Citra, FL in summer 2012, with the aim of submitting them to the UF/Institute of Food and Agricultural Sciences (IFAS) Cultivar Release Committee for approval in October 2012. Plants were clonally propagated and transplanted to the field in June. They were evaluated monthly until September for overall performance (on a scale from 1-5), and plant height and width were measured. Finally, the company in California decided against commercializing the three Coleus selections, therefore they were not submitted for cultivar release. Six other ornamental foliage selections and three Ruellia selections developed in this program are currently in commercial trials in two sites in Florida. PARTICIPANTS: Freyre, R., Moseley, A., Bottenhorn, M., Ellison, K. TARGET AUDIENCES: Commercial ornamental growers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Six ornamental foliage selections and three Ruellia selections developed in this program are currently in commercial trials in two sites in Florida.

Publications

  • No publications reported this period


Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: Cultivar release of three Coleus University of Florida (UF) selections is pending. Six ornamental breeding UF selections are currently in commercial trials in Mexico, and three Ruellia selections are currently in commercial trials in California. PARTICIPANTS: Freyre, R., Moseley, A., Bottenhorn, M., Ellison, K. TARGET AUDIENCES: Commercial growers of ornamental plants. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Ornamental foliage plants obtained from mutation breeding were selected after field or greenhouse trials in 2010. So far, there is commercial interest in three selections that are derived from a plant named commercially as Perilla. However our taxonomical evaluation has indicated that these lines are actually Plectranthus scutellarioides (Coleus) and not Perilla. Landscape performance evaluation of these three Coleus selections was performed in Citra, FL in summer 2012. Plants were clonally propagated and transplanted to the field in June. They were evaluated monthly until September for overall performance (on a scale from 1-5), and plant height and width were measured. These selections will be submitted to the UF/Institute of Food and Agricultural Sciences (IFAS) Cultivar Release Committee for approval in October 2012.

Publications

  • No publications reported this period


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

Outputs
OUTPUTS: Breeding sterile, non-invasive Ruellia brittoniana (Mexican Petunia): Ruellia tetraploid plants in four different flower colors were obtained in 2009 from treatment of diploid plants with oryzalin. Two tetraploid plants in each flower color were chosen for manual hybridizations. A total of 125 4x x 2x hybridizations were performed and only 7.2% resulted in fruit production. A total of 96 seeds were obtained, 18 of which appeared plump and viable. A total of 26 2x x 4x hybridizations were performed and 54% resulted in fruit production. A total of 238 seeds were obtained, 49 of which appeared plump and viable. Additional hybridizations were performed between different species and morphotypes of Ruellia, as well as other interploidy combinations. Seeds from selfing of 4x individuals were also collected. All seeds were sown and 495 seedlings were obtained, 7 resulting from 4x x 2xhybridizations, 18 from 2x x 4x hybridizations, and 470 from other interploidy combinations, interspecific hybridizations and selfing of 4x individuals. Progenies were grown and selected in a greenhouse at Gainesville. Flow cytometry evaluations and determination of female and male fertilities are in progress. So far, triploid individuals with purple flowers have been obtained. Additionally, mutant plants derived from irradiation have been obtained in all four flower colors. Female sterility and lack of fruit formation has been confirmed in both field and greenhouse trials in Gainesville. Breeding low maintenance foliage ornamental plants: Breeding lines of Graptophyllum, Strobilanthes, Sanchezia, Alternanthera, Iresine, Perilla, Pseuderanthemum, Justicia, Hibiscus and Hemigraphis were obtained by irradiation treatments or by hybridizations. Selected lines are currently in commercial trials under material transfer agreements. PARTICIPANTS: Adam Moseley, Taylor Jeanot, Connie Johnson. University of Florida, Gainesville. TARGET AUDIENCES: Florida landscape and nursery industry PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Ruellia plants in four different flower colors and with lack of fruit production have been obtained by mutation breeding or ploidy manipulation. Further multilocation field trials will be conducted to evaluate ornamental performance and confirm sterility, with aim to release new non-invasive Ruellia cultivars. Chemical polyploidization treatments were effective in producing Ruellia tetraploid plants in four different flower colors. Progenies derived from selfing these plants were obtained, which will facilitate further 4x x 2x hybridizations aiming to produce sterile triploid plants. Two undergraduate students were trained in plant breeding techniques, and one graduate student was trained in cultivar field performance evaluations.

Publications

  • No publications reported this period


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

Outputs
OUTPUTS: Two Ruellia breeding lines developed in this project and three commercial cultivars as controls were evaluated in replicated field trials at four locations: Citra, Balm, Fort Pierce and Quincy, FL. Sterility was confirmed on one new Ruellia breeding line with purple flowers. A pink-flowered breeding line had significantly lower fruit and seed production than the existing pink- flowered commercial cultivar (R. brittoniana ChiChi). Ruellia tetraploid plants displaying four different flower colors were obtained using oryzalin. Ploidy level was determined with flow cytometry. Interploidy 4x x 2x and 2x x 4x hybridizations were performed aiming to obtain sterile triploid plants. Seed has been sown and progenies will be grown and evaluated in 2010. Artificial hybridizations confirmed potential interspecific hybridization between the FL native R. caroliniensis and invasive R. brittoniana. Interspecific hybrids were obtained using R. caroliniensis as the maternal parent. Floral and vegetative morphology in the hybrids was intermediate between the two parental species. Hybrids had very low vigor, high mortality and were sterile. Therefore the risk of genetic drift from invasive R. brittoniana into native R. caroliniensis populations in natural areas is considered negligible. A total of 83 foliage breeding lines developed in this project were under Material Transfer Agreements in 2009 with six floriculture companies for potential cultivar release. PARTICIPANTS: Erin A. Tripp - postoctoral researcher, Santa Ana Botanical Garden, CA. Adam Moseley - UF undergraduate student. Kelly Elison - UF undergraduate student. Taylor Jeanot - UF undergraduate student. TARGET AUDIENCES: Florida landscape and nursery industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Breeding sterile, non-invasive Ruellia brittoniana (Mexican Petunia): Approximately 400 new progenies were obtained this year by classical breeding. Furthermore, seeds of 12 breeding lines were irradiated with gamma rays at 0, 50, 100, 150, 200 and 300 Gy. All hybrids and mutants were evaluated in a summer field trial at Citra, FL. Eighty breeding lines were selected for ornamental value, novel flower color and no fruit production. Further greenhouse evaluations to confirm sterility are in progress. Additionally, three control cultivars and two new breeding lines were evaluated during 32 weeks in a multi-location field trial in Citra, Balm, Fort Pierce and Quincy, FL. Research is in progress aiming to obtain sterile triploid plants. Our results indicated that Ruellia is recalcitrant to micropropagation, thus polyploidization in vivo was attempted using oryzalin. Apical meristems in germinated seedlings were treated with a semi-solid agar solution containing either 25 or 50 micromolar oryzalin applied 1, 2, 3 or 4 times at 3-day intervals. Treated plants were analyzed with flow cytometry. Tetraploid plants with purple, pink, and white and purple flower colors have been obtained. A total of 125 4x x 2x and 26 2x x 4x hybridizations were performed and seed has been sown. Artificial hybridizations were conducted to determine cross compatibility between the FL native R. caroliniensis and invasive R. brittoniana. Forty one hybrids were obtained using R. caroliniensis as maternal parent. Hybrids had intermediate morphology, very low vigor, and 49 percent mortality 30 days post germination. Five hybrids bloomed and were found to be both female and male sterile. Crosses using R. brittoniana as maternal parent resulting in forty progeny. Their morphology was similar to the maternal parent which may be indicative of accidental self pollination. Data was generated and analyzed from the nuclear ribosomal ITS region for the two parental species and hybrids in collaboration with E. Tripp, Santa Ana Botanical Garden. Data consistently resolved parental species into two different clades, and the artificial hybrids resolved into the clades carrying their maternal genome. Breeding low-maintenance foliage ornamental plants: Plant material of Pseuderanthemum, Graptophyllum, Strobilanthes, Sanchezia, Alternanthera, Iresine, Perilla, and Hemigraphis, and flowering herbaceous plants Crossandra and Justicia was used in irradiated treatments. Cuttings were taken from visibly affected regions and selected for variations in foliage color, variegation and compact growth. Mutants were propagated vegetatively for several generations to stabilize mutations. Manual hybridizations were performed on flowering plants of Pseuderanthemum, Crossandra and Justicia with limited success. A total of 72 selected mutants and two hybrids were evaluated in field summer trials from March until September in Citra, FL. Additionally, a subset of 31 selected breeding lines and 25 control cultivars were trialed for 8 weeks an outdoor container trial under two irrigation regimes. Plants were evaluated for overall performance, wilt, plant and foliage damage, vigor and vegetative growth.

Publications

  • Wilson, S.B, G.W. Knox, K.L. Muller, R. Freyre and Z. Deng. 2009. Seed production and viability of eight porterweed selections grown in northern and southern Florida. HortScience 44:1842-1849.
  • Non refereed: Freyre, R., J. Henny, Z. Deng, B. Harbaugh and D. Clark. June 2009. Breeding brilliance. Greenhouse Product News 9(6):28-32.