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Plant Biology Home

Phone: (612) 625-1234
Fax: (612) 625-1738

Department of Plant Biology
University of Minnesota
250 Biological Science Center
1445 Gortner Ave.
St. Paul, MN 55108

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Willard L. Koukkari

Professor Emeritus, Department of Plant Biology
Horace T. Morse Alumni Distinguished Teaching Professor
Ph.D., University of New Hampshire, 1962

Biological oscillations and the temporal organization of plant development

Contact Information

Mailing Address:

Dr. Willard Koukkari
Department of Plant Biology
University of Minnesota
220 Biological Science Center
1445 Gortner Ave.
St. Paul, MN 55108

Office: 610 Biological Sciences Center
Phone: 612-625-1958
Fax: 612-625-1738
E-mail: koukk001@umn.edu

Research Interests

My research focuses on the physiology of plant growth and development, especially as it relates to timing mechanisms. In plants, as in other organisms, biological rhythms and oscillation are integral components of timing and are found at all levels of organismal complexity. The list of biological variables that oscillate range from the molecular to the ecosystem level. Over the years, research in my laboratory has been directed towards examining time responses at these levels, with an emphasis upon such processes and variables as enzyme activity, plant development, photomorphogenesis, leaf movements, circumnutations, plant hormones, herbicides, and environmental stress.

Sothern, R.B., Tseng, T.S., Orcutt, S.L., Olszewski, N.E., Koukkari, W.L. 2002. Gigantea and spindly genes linked to the clock pathway tht controls circadian characteristics of transpiration in Arabidopsis. Chronobiol Int. 19(6):1005-22.

Martinson, K.B., Sothern, R.B., Koukkari, W.L., Durgan, B.R., and Gunsolus, J.L. 2002. Circadian response of annual weeds to glyphosate and glufosinate. Chronobiol. Int. 19(2):405-22.

Sothern, R.B., Hermida, R.C., Nelson, R., Mojon, A. and Koukkari, W.L. 1998. Reanalysis of filter-feeding behavior of caddis fly (Brachycentrus) larvae reveals masking and circadian rhythmicity. Chronobiol. Int. 15(6):595-606.

Koukkari, W.L., C. Bingham, J.D. Hobbs, and S. H. Duke. 1997. In search of a biological hour. Journal of Plant Physiology 151:352-357.

Anderson-Bernadas, C., G. Cornelissen, C.M. Turner, and W. L. Koukkari. 1997. Rhythmic nature of thigmormorphogenesis and thermal stress of Phaseolus vulgaris L. shoots. Journal of Plant Physiology 151: 575-580.