- About Us
1. Joseph Rothleutner- past Masters student
2. Jason Lattier - Ph.D. student
3. Justin Schulze - M.S. Student
4. Kim Shearer-Lattier - M.S. Student
Mara Friddle joined the ornamental breeding program at OSU as a lab technician in 2010. Mara helps with daily plant maintenance for making crosses, testing ploidy levels with a flow cytometer, cleaning, weeding, data collection, and ensuring all current projects are moving forward. She received her Bachelor’s Degree from Colorado State University in Horticulture with a concentration on nursery and landscape management. Prior to joining OSU, Mara worked for 8 years as canola breeding technician.
In 2011, Nursery and Greenhouse crops were ranked the top commodity in Oregon with a farmgate economic value of $742 million dollars. It is estimated in 2013 that the economic value will exceed $1 billion dollars as it has been in previous years. Oregon is central to the ornamental industry, exporting ornamental and nursery plants all over the United States.
Due to the high diversity of the ornamental plant industry, a large number of plants are studied to produce economically important and ecologically sound varieties that are disease and pest resistant, heat tolerant, and non-invasive so they do not impede native landscapes. Newly released plants with these traits have health and safety benefits, lower the economic cost to homeowners and gardeners, and benefit the ornamental plant industry in the United States.
Lattier, J.D. and R.N. Contreras. 2014. Hybridization Studies in Lilacs (Syringa L.). Proc. 59th Ann. SNA Res. Conf. 59:229-234.
Contreras, R.N. 2014. Ornamental Plant Breeding at Oregon State University. Combined Proceedings of the International Plant Propagators' Society 63. <http://www.pubhort.org/members/ippsue?session=>
Contreras, R.N., J. Rothleutner, and V. Stockwell. 2014. Breeding for fire blight resistance and sterility in Cotoneaster. Proceedings of the 13th International Workshop on Fire Blight. Acta Hort. 1056:221-223.
Contreras, R.N., M. Friddle, and J.D. Lattier. 2013. Relative fertility and ploidy levels of selected rose of sharon cultivars. Proc. 58th Ann. SNA Res. Conf. 58:232-236.
Rothleutner, J.J., R.N. Contreras, and V. Stockwell. 2012. Evaluation of fire blight resistance of 31 species of Cotoneaster. Proc. 57th Ann. SNA Res. Conf. 57:276-278.
Contreras, R.N. and J.M. Ruter. 2010. Induced polyploidy in Japanese cedar. Proc. 55th Ann. SNA Res. Conf. 55:25-29.
Contreras, R.N. and J.M. Ruter. 2008. Preliminary efforts to induce polyploidy in Cryptomeria japonica. Proc. 53rd Ann. SNA Res. Conf. 53:159-161.
Contreras, R.N. and J.M. Ruter. 2007. New Callicarpa species with breeding potential. Proc. 52nd Ann. SNA Res. Conf. 52:327-329.
Contreras, R.N., T.G. Ranney, S.P. Tallury and S.R. Milla. 2005. Using molecular markers to investigate parentage of azaleodendron hybrids. 2005. Proc. 50th Ann. SNA Res. Conf. 50:632-635.
Contreras, R.N. and T.G. Ranney. 2004. New opportunities for breeding allopolyploid azaleodendrons. Proc. 49th Ann. SNA Res. Conf. 49:552-554.
Lattier, J.D. and R.N. Contreras. 2014. Colorimetric phenotyping of tetraploid progeny exhibiting incomplete dominance for flower color. Independent Plant Breeders Conference. Grand Rapid, MI
Shearer-Lattier, K. and R.N. Contreras. 2014. Non-targeted mutagenesis of Galtonia candicans by exposing seeds to EMS. Independent Plant Breeders Conference. Grand Rapid, MI, October 30 – November 2, 2014.
Contreras, R.N. and L. Meneghelli. 2013. In Vitro Chromosome Doubling of Prunus laurocerasus ‘Otto Luyken’. Proc. 109th Ann. Amer. Soc. Hort. Sci. Res. Conf. HortScience (Accepted) (Abstr.)
Schwartz, B.M., R.N. Contreras, W.W. Hanna, and S.A. Jackson. 2013. Manipulating the Chromosome Number of Zoysiagrass. ASA-CSSA-SSSA Abstracts 2013. (Abstr.)
Schwartz, B.M., R.N. Contreras, K.R. Harris-Schultz, J.B. Peake, and P.L. Raymer. 2012. Identification or Creation of a Putative Triploid Seashore Paspalum. ASA-CSSA-SSSA Abstracts 2012. (Abstr.)
Rothleutner, J.J. and R.N. Contreras. 2012. Variable Fire Blight Resistance Among 31 species of Cotoneaster. Proc. 109th Ann. Amer. Soc. Hort. Sci. Res. Conf. HortScience 47(9):S366 (Abstr.)
Einhorn, T., Gibeaut, D., Contreras, R.N., and Whiting, M. 2012. Polyploidy of cells in sweet cherry fruit. Proc. 109th Ann. Amer. Soc. Hort. Sci. Res. Conf. HortScience 47(9):S387 (Abstr.)
Gibeaut, D., R. Contreras, T. Einhorn, and M. Whiting. 2011. Cropload affects the size, but not the number or polyploidy of cells in sweet cherry fruit. Washington State Horticultural Association 107th Annual Meeting, Wenatchee, WA, December 5-7, 2011.
Contreras, R.N., J.M. Ruter, J. Conner, Y. Zeng, and P. Ozias-Akins. 2011. Interspecific hybridization in Tecoma Juss. (Bignoniaceae): Confirmation of hybridity using GISH and morphology. HortScience 46(9):S320. (Abstr.)
Rothleutner, J.J. and R.N. Contreras. 2011. Genome size estimates for Cotoneaster spp. HortScience 46(9):S386 (Abstr.)
Schwartz, B., K. Harris, R.N. Contreras, and W. Hanna. 2010. Colchicine-induced tetraploidy in centipedegrass. ASA-CSSA-SSSA Abstracts 2010 (in press). (Abstr.)
Contreras, R.N. 2010. Breeding methods to reduce the invasive potential of nursery crops. HortScience 45(8):S29 (Abstr.)
Contreras, R.N. and John M. Ruter. 2010. Fruit color in American beautyberry is controlled by a single gene. HortScience 45(8):S280 (Abstr.)
Contreras, R.N. and John M. Ruter. 2009. An oryzalin induced polyploidy from a hybrid of Hibiscus acetosella x H. radiatus(Malvaceae) exhibits reduced fertility and altered morphology. Proc. 106th Ann. Amer. Soc. Hort. Sci. Res. Conf. HortScience 44(4):1177.
Contreras, R.N. and John M. Ruter. 2008. Evaluation of Callicarpa spp. for ornamental potential. Proc. 105th Ann. Amer. Soc. Hort. Sci. Res. Conf. HortScience 43(4):1266.
Contreras, R.N. and Thomas G. Ranney. 2006. Reproductive behavior of diploid and allotetraploid azaleodendrons. Proc. 66th Ann. SR-ASHS Res. Conf. HortScience 40(3):497-498.
Shearer Lattier, K. and R.N. Contreras. 2015. Penstemon breeding in the Willamette Valley: A lesson in flexibility. Bulletin of the American Pestemon Society (Accepted).
Contreras, R.N. and J.D. Lattier. 2014. Improving a garden classic. Digger, August:47-50.
Contreras, R.N. and M. Horn. 2014. Breeding to improve garden performance of Penstemon in the Willamette Valley: early stages. Bulletin of the American Pestemon Society 73:68-72.
Contreras, R.N. and G. McAninch. 2013. Back from the ban: new Buddleja cultivars receive exemption under ODA amendment. Digger, October:33-36.
Contreras, R.N. and T. Rinehart. 2012. An express route to perfection. Digger, August: 47-50.
Rothleutner, J.J. and R.N. Contreras. 2012. Celebrating Cotoneaster. Digger, January:33-36.
Contreras, R.N. and J.S. Owen. 2011. The Economy of Water. Digger, August:139-144.
Contreras, R.N. 2011. Bred for success. Digger March:41-45.
Contreras, R.N. 2010. Bridging the gap: A new partnership between Oregon State University and LPDC designed to continue cultivar development. Landscape Plant News
Contreras, R.N. and J.M. Ruter. 2010. Developing an evergreen, evergreen: Winter browning in Japanese cedar. Amer. Conifer Soc. Quarterly J. 27(1):19-23.
Contreras, R.N. and John M. Ruter. 2009. Callicarpa evaluation and breeding at The University of Georgia Tifton Campus. Landscape Plant News 20(2):3-5.
Contreras, R.N. and John M. Ruter. 2008. Evaluation of Callicarpa spp. for utilization in a breeding program. Georgia Green Industry Association Journal. May/June 32-33.