Water Stress Effect on Total Antioxiant Activity and Total Phenolic Content of Solanum scabrum Mill and Solanum scabrum in Kiambu, Kenya
Odhiambo Peter Okello *
Department of Agricultural Science and Technology, Kenyatta University, P.O.Box 43844, Nairobi, Kenya
Mildred P. Nawiri
Department of Agricultural Science and Technology, Kenyatta University, P.O.Box 43844, Nairobi, Kenya
Winfred Musila
Department of Agricultural Science and Technology, Kenyatta University, P.O.Box 43844, Nairobi, Kenya
Joseph P. Gweyi-Onyango
Department of Agricultural Science and Technology, Kenyatta University, P.O.Box 43844, Nairobi, Kenya
*Author to whom correspondence should be addressed.
Abstract
Aims: The aims of this study were to investigate water stress effect on total phenolics and total antioxidants of selected African nightshades and determine any possible variations in the amount of total phenolics and total antioxidants among the accessions grown.
Study Design: Study was conducted on the basis of randomized complete block design.
Place and Duration of Study: The study was carried out in Kenyatta University Agricultural farm in Kiambu County of Kenya. Greenhouse experiments were carried out in the same farm.
Methodology: A greenhouse and field experiment was conducted to investigate effects of water stress on total phenolic and total antioxidant contents of Solanum scabrum and Solanum villosum. The two African nightshades were subjected to different soil water tensions of 15cbars, 50cbars and 85cbars. After a month of transplanting, samples from the different blocks were collected fortnightly and prepared for total phenolic and total antioxidant determination.
Results: Obtained data showed that Solanum villosum had a higher concentration of both the total phenolics and antioxidant activity in the shoots (46.41 g/Kg total phenolic content and 52.68% total antioxidant activity) while Solanum scabrum had higher concentration in the roots (25.06 g/Kg total phenolic content and 27.18% total antioxidant activity).
Conclusion: Total phenolics and total antioxidant accumulation not only depend on irrigation variation but also on the accessions grown.
Keywords: Phytochemical concentration, phenolic content, antioxidant activity