Morphological and Physiological Responses of Clinacanthus Nutans Under Different Light Conditions

Abstract

Abiotic stress such as light stress can cause injuries or damage to the plant cells or biochemical processes in the plants. Difference of light conditions resulted in different morphological and physiological responses of plants. This study is done to determine the response of Clinacanthus nutans under different light condition as the results of plant defense mechanism. Clinacanthus nutans is one of the plant species that contains higher medicinal value and currently being commercialised as alternative treatment to treat various ailments. Four weeks of treatment was done on five samples of Clinacanthus nutans in each condition. Observation done morphologically shows that samples under condition A (exposed fully under sunlight) appear bigger in stem diameter, longer in root length, higher in plant height and pale in colour compared to samples in condition B (shaded under polyethylene netting). However, for leaf size parameter, samples in condition B has bigger leaves compared to condition A. Meanwhile, for physiological analysis, shows that there is difference in chlorophyll content based on different condition (0.83 ± 0.463 Ca, 1.46 ± 0.740 Cb and 0.03 ± 0.015 carotenoids for condition A, and 0.50 ± 0.321 Ca, 1.47 ± 0.539 Cb and 0.03 ± 0.105 carotenoids for condition B) and samples under condition A contain higher photosynthetic rate as a result of higher dry matter content (0.27 ± 0.017) in plants. It is suggested that to ensure the results is more accurate, the period of treatment should be longer and analysis on primary and secondary metabolites should be conducted.