Plant Ecophysiology
The way different environmental conditions affect plant function, especially photosynthesis is fascinatingly unpredictable. I am especially interested in studying how light-dependent and carbon assimilatory processes adjust in response to environmental stress. I also attempt to find if useful phytochemicals are elicited during such adjustments.
Continuing work
Comparative physiology of wild type (TM) and immature mutant (im) cotton – with Dr. Hee Jin Kim, USDA, New Orleans.
Identification of smooth cord grass genotypes with possible tolerance to petroleum oil
- Physiological measurements on smooth cord grass in Barataria Bay, LA after the 2010 oil spill. August, 2012.
Some past work
Ratnayaka HH. Sangakkara UR. 1988. Cowpea (Vigna unguiculata Walp) as a component of alley cropping. Sri Lankan Journal of Agricultural Science 25:75-82.
* Corresponding author, ** Xavier student
Some student presentations
Johnson C*, Vu T*, Opusunju N, Arasah A*, Stern K*, Kim HJ, Ratnayaka HH. 2017. Comparative photosynthetic physiology of near isogenic cotton lines differing in the degree of fiber cell wall thickness in cotton (Gossypium hirsutum L.). American Society of Plant Biologists Annual Conference. June 24-28, Honolulu, HI. Poster # 1200-012. https://www.eventscribe.com/2017/ASPB/PosterTitles.asp?h=Posters%20and%20Abstracts
Gordon M*, Arasah A*, Stern K*, Kim HJ, Ratnayaka HH. 2016. Photosynthesis and growth characteristics of cotton immature fiber mutant (im) in comparison with isogenic wild type (TM-1). American Society of Plant Biologists Annual Conference. July 9-13, Austin, TX. http://www.eventscribe.com/2013/ app/tweets.asp?AccountID=9908822&EventID=2088&ClientID=253&PresentationID=&BoothID=&PresenterID=&PosterID=63587
Opusunju N*, Humphrey A*, Gabriel K*, Ugbaja C*, Combe S, Boue S, Ratnayaka HH. 2015. Photosynthetic physiology and kaempferol yield affected by leaf treatments in soy plants. American Society for Horticultural Science Annual Conference. August 4-7, New Orleans, LA. https://ashs.confex.com/ashs/2015/poster/papers/index.cgi?username=21392&password=523062
Opusunju N*, Kofi B*, Etuk I*, Cook A*, Combe S, Ratnayaka HH. 2014. Physiological recovery of smooth cord grass (Spartina alterniflora Loisel.) in Barataria Bay after oil spill. State of the Coast Conference, March 18-20, New Orleans, LA. http://www.stateofthecoast.org/image/SOC14_Accepted_Posters_01152014.pdf (page 48, poster#24)
Cook A*, Onuaguluchi D*, Jackson J*, Patterson B*, Gilbert L4, Combe S, Ireland S, Muniruzzaman S, Boue S, Ratnayaka HH. 2013. Elicitation of physiological stress and kaempferol accumulation of soybean by sugar treatment. American Society for Horticultural Science Annual Conference. July 22-25, Palm Desert, CA. http://www.ashs.org/index.php?option=com_content&view=article&id=1302:2013-ashs-undergraduate-student-oral-competition-winners&catid=57:student-membership&Itemid=131
Combe S, Bernik B5, Jackson J*, Ojukwu K*, Davenport I, Knott C, Blum M, Ratnayaka HH. 2012. Comparative physiology of natural and cultivar genotypes of coastal marsh grass, Spartina alterniflora. American Society of Plant Biologists Annual Conference. July 20-24, Austin, TX. http://c.ymcdn.com/sites/my.aspb.org/resource/resmgr/Docs/Final_Program_Book.pdf (page 98, P07010)
3Wiessner G, Dinh T*, Muniruzzaman S, Izumori K, Boue S, Ratnayaka HH. 2011. Photosynthetic and leaf kaempferol profiles of soy seedlings under rare sugar treatment. 5th Rare Sugar Congress – Proceedings p 33. 9-12 Nov. Kagawa, Japan.
Dinh T*, Mustahsan W*, Boue S, Ratnayaka HH. 2011. Photosynthetic biochemistry and kaempferol profiles of soybean under leaf wounding and abscisic acid treatments. American Society for Horticultural Science Annual Conference. 25-28 Sept. Waikaloa, HI. http://www.ashs.org/index.php?option=com_content&view=article&id=988:2011-winnersashs-undergraduate-student-oral-competition&catid=57:student-membership&Itemid=131
Le S*, Cherubin R*, Boue S, Bhatnagar D, McLachlan J, Ratnayaka HH. 2010. Photosynthetic, Antioxidant and anticancer properties of soybean under drought and mechanical wounding. American Society for Horticultural Science Annual Conference. 2-5 August. Palm Desert, CA. http://ashs.confex.com/ashs/2010/webprogram/Paper4201.html
Cherubin R*, Ratnayaka HH. 2009. Photosynthetic Properties of Soybean [Glycine max L. (Merr.)] under drought and mechanical wounding. Annual Biomedical Research Conference for Minority Students, Nov. 4-7. Phoenix, AZ.
Le S*, Ratnayaka HH. 2009. Antioxidant and anticancer properties of soybean under drought and mechanical wounding. Annual Biomedical Research Conference for Minority Students, Nov. 4-7. Phoenix, AZ.
Cherubin R*, Do T*, Rajasekaran K, Gossett D, Ratnayaka HH. 2009. Photosynthetic, antioxidant and leaf ultrastructural responses to drought in two spinach cultivars of contrasting morphology. American Society for Horticultural Science Annual Conference. July 24-28, St. Louis, MO. http://ashs.confex.com/ashs/2009/webprogram/Paper2146.html
Do T*, Carey T*, Rajasekaran K, Ratnayaka HH. 2008. Physiological, growth and leaf surface characteristics toward understanding drought tolerance in Big Chili and Jalapeño pepper. American Society for Horticultural Science Annual Conference. July 21-24. Orlando, FL. HortScience 43:1275-76.
Hardy W*, Carey T*, Burnett A*, Shinkle J, Ratnayaka HH. 2007. Gas exchange and photosystem II responses of two spinach cultivars with contrasting morphology to moderate salt stress. American Society for Horticultural Science Annual Conference. July 16-19. Scotsdale, AZ. HortScience 42:943.
Williams FJ*, Barbarin AM*, Hauber DP, Ratnayaka HH. 2006. Drought acclimation of leaf gas exchange in Jalapeño and Big Chili pepper. American Society for Horticultural Science Annual Conference. July 27-30. New Orleans, LA. HortScience 41:1058.
Shinkle J, Hammer M2, Ratnayaka HH. 2006. Rapid transient induction of increased antioxidants by brief UV-B radiation. American Society of Plant Biologists Annual Conference. Aug. 5-9. Boston, MS.
Barbarin AM*, Williams FJ*, Bettmann GT1, Hauber DP, Ratnayaka HH. 2005. Gas exchange and antioxidant properties of two spinach (Spinacia oleracea L.) cultivars of contrasting morphology. American Society for Horticultural Science Annual Conference. July 18-21. Las Vegas , NV. HortScience 40:1057.
Undergraduate author is underlined. *Xavier University Undergraduate, 1New Mexico State University Undergraduate, 2Trinity University Undergraduate, 3Warren Wilson College Undergraduate, 4University of Pikeville Undergraduate, 5Tulane University Graduate Student
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