Ryan Warner

Ryan Warner


Department of Horticulture

Associate Professor

Telephone: (517) 353-0344

1066 Bogue St, Room A234
East Lansing, MI 48824

Area of Expertise:

Genetics of plant development; genomics-assisted breeding; marker-assisted selection; floriculture crops.

Quick links: Education    Publications    Research

Joined Department

September 1, 2004


75% Research

25% Teaching


Ph.D., Applied Plant Sciences, University of Minnesota, 2004

M.S., Horticultural Science, University of Minnesota, 1999

B.S., Horticulture, Michigan State University, 1996

Graduate Programs

Plant Breeding, Genetics and Biotechnology


Genetic Determinants of Crop Development and Quality

Being sessile organisms, plants are often subjected to suboptimal or supraoptimal environmental conditions, including temperature, light intensity, and water availability. These environmental variables influence crop timing and quality. My lab is broadly interested in understanding the genetic control of these traits, with a particular emphasis on how development rate during the vegetative phase is controlled, including the temperature sensitivity of this process.

The rate at which plants produce new nodes (development rate) is a fundamental biological process that impacts agriculture through control of crop timing and biomass accumulation. The long-term goal of this project is to elucidate the genetic determinants of plant development rate and utilize this knowledge to facilitate breeding of superior agricultural crop varieties. Unfortunately, the genetic control of development rate is poorly understood. My lab is utilizing genomics, QTL mapping, and differential gene expression analysis between fast- and slow-developing recombinant inbred lines from an interspecific Petunia population to identify and functionally characterize candidate genes putatively involved in control of this developmental process.

Breeding and Genetics of Stevia

Stevia rebaudiana (stevia) is a rapidly emerging new crop in the U.S. and worldwide, grown for the extraction of sweet-tasting steviol glycosides used as natural non-caloric sweeteners in food and beverage applications. My lab is breeding new varieties of stevia with an emphasis on improving production of steviol glycosides with a superior taste profile to what is currently available. Additionally, we are developing genetic and genomic resources to facilitate understanding of traits important for agricultural production and steviol glycoside biosynthesis.


Peer Reviewed Publications

Guo, Y., Lin W.-K., Chen Q., Vallejo V.A., Warner R.M. (2017) Genetic determinants of crop timing and quality traits in two interspecific Petunia recombinant inbred line populations. Scientific Reports 7:3200. 

Bombarely, A., M. Moser, A. Amrad, M. Bao, L. Bapaume, C. S. Barry, …, R.M. Warner, et al. (2016). Insight into the evolution of the Solanaceae from the parental genomes of Petunia hybrida. Nature Plants 2: 16074

Guo, Y., Wiegert-Rininger, K., Vallejo, V. A., Barry, C. S., Warner, R.M. (2015) Transcriptome-enabled marker discovery and mapping of plastochron-related genes in Petunia spp. BMC Genomics, 16:726. 

Vallejo V.A., Tychonievich J., Lin W.-K., Wangchu L., Barry C.S., Warner R.M. (2015) Identification of QTL for crop timing and quality traits in an interspecific Petunia population. Mol. Breed. 35:2 DOI 10.1007/s11032-015-0218-4.  

Evans, J.M., Vallejo, V.A., Beaudry, R.M., Warner, R.M. (2015) Daily light integral influences steviol glycoside biosynthesis and relative abundance of specific glycosides in stevia. HortScience 50:1479-1485. 

Walworth, A.E., G.-Q. Song and R.M. Warner (2014). Ectopic AtCBF3 expression improves freezing tolerance and promotes compact growth habit in petunia. Mol. Breed. 33:731-741 DOI 10.1007/s11032-013-9989-7 

Tychonievich, J., L. Wangchu, C. Barry and R.M. Warner (2013). Utilizing wild species for marker-assisted selection of crop timing and quality traits in Petunia. Acta Hortic. 1000:465-470.

Shafii, B., Vismeh, R., Beaudry, R., Warner, R. and Jones, A.D. (2012). Large-scale profiling of diterpenoid glycosides from Stevia rebaudiana using ultrahigh performance liquid chromatography/tandem mass spectrometry. Anal. and Bioanal. Chem. 403:2683-90.

Tychonievich, J. and R.M. Warner (2011) Interspecific crossability of selected Salvia spp. and potential utility for crop improvement. J. Amer. Soc. Hort. Sci.  136:41-47.

Warner, R.M. and A.E. Walworth (2010). Quantitative inheritance of crop timing traits in interspecific hybrid Petunia populations and interactions with crop quality parameters. J. Hered. doi: 10.1093/jhered.esp131 (pdf)

Bradford, E., J.F. Hancock and R.M. Warner (2010). Interactions of temperature and photoperiod determine expression of repeat flowering in strawberry. J. Amer. Soc. Hort. Sci. 135:102-107.

Warner, R.M. (2010). Temperature and photoperiod influence flowering and morphology of four Petunia spp. HortScience 45:365-368.

Stegmeir, T.L., C.E. Finn, R. M. Warner and J.F. Hancock (2010). Performance of an elite strawberry population derived from wild germplasm of Fragaria chiloensis and F. virginiana. HortScience 45:1140-1145.

Oh, W., E. Runkle and R. Warner (2010). Timing and duration of supplemental lighting during the seedling stage influence quality and subsequent flowering in petunia and pansy. HortScience 45: 1332-1337.

Walworth, A.E. and R.M. Warner (2009). Differential cold-acclimation ability of Petunia species. HortScience 44:1219-1222.

Warner, R.M. (2009). Determination of the photoperiod sensitive stages of development of the short-day plant celosia. HortScience 44: 328-333.

Warner R.M. and J.E. Erwin (2006). Prolonged high temperature exposure differentially reduces growth and flowering of twelve Viola × wittrockiana Gams. cvs. Sci. Hort. 108:295-302.

Warner, R.M. (2006). Using limited inductive photoperiod for scheduling Cosmos bipinnatus and Tagetes tenuifolia. Acta Hortic. 711:267-271.

Warner, R.W. and J.E. Erwin (2005). Naturally occurring variation in high temperature induced floral bud abortion across Arabidopsis thaliana accessions. Plant Cell Environ. 28:1255-1266.

Warner, R.W. and J.E. Erwin (2005). Prolonged high temperature exposure and daily light integral impact growth and flowering of five herbaceous ornamental species. J. Amer. Soc. Hort. Sci. 130:319-325.

Warner, R.M. and J.E. Erwin (2003). Effect of photoperiod and daily light integral on flowering of five Hibiscus sp. Scientia Hortic. 97:341-351.

Warner, R.M and J.E. Erwin (2003). Effect of plant growth retardants on hibiscus species stem elongation. HortTechnology 12:293-296.

Erwin, J.E., R.M. Warner and A.G.Smith (2002). Vernalization, photoperiod and GA3 interact to affect flowering of Japanese radish (Raphanus sativus Chinese Radish Jumbo Scarlet). Physiol. Plant. 115:298-302.

Erwin, J.E. and R.M. Warner (2002). Determination of photoperiodic response group and effect of supplemental irradiance on flowering of several bedding plant species. Acta Hortic. 580:95-99.

Warner, R.M. and J.E. Erwin (2002). Estimation of total canopy photosynthetic capacity of roses grown under two canopy management systems. Acta Hortic. 580:89-93.

Warner, R.M. and J.E Erwin (2002). Photosynthetic responses of heat-tolerant and heat-sensitive cultivars of Impatiens hawkeri and Viola x wittrockiana to high-temperature exposures. Acta Hortic. 580:215-219.

Warner, R.M. and J.E. Erwin (2001). Variation in floral induction requirements of Hibiscus sp. J. Amer. Soc. Hort. Sci. 126:262-268.

Book Chapters

Warner, R. (2004). Lighting greenhouse cut flowers, p. 89-92. In:P. Fisher and E Runkle (eds.). Lighting up profits: understanding greenhouse lighting. Meister Media Worldwide, Willoughby, Ohio.

Erwin, J, N. Mattson and R. Warner (2004). Light effects on annual bedding plants, p.62-71. In:P. Fisher and E Runkle (eds.). Lighting up profits: understanding greenhouse lighting. Meister Media Worldwide, Willoughby, Ohio.

Warner, R.M. and J.E. Erwin (2001). Temperature. p.10-17. In: M.L. Gaston, P.S. Konjoian et al. (eds.). Tips on regulating growth of floriculture crops. O.F.A. Services, Inc. Columbus, Ohio.

Erwin, J.E. and R.M. Warner (1999). Temperature. p.69-82. In: C.A.Buck , S.A. Carver et al. (eds.). Tips on growing bedding plants. 4th ed. O.F.A. Services, Inc. Columbus, Ohio.