Abstract

EFFECT OF ELEVATED CO2 ON GROWTH AND BIOCHEMICAL CHANGES IN CATHARANTHUS ROSEUS - AN VALUABLE MEDICINAL HERB

S. Saravanan* and S. Karthi

ABSTRACT

Increasing atmospheric CO2 concentration is generally expected to enhance plant growth, allocation and chemical composition of alkaloids in medicinal plants.The response to the elevated CO2 concentrations of various medicinal plants were studied with reference to growth and biochemical changes. Catharanthus roseus is an important medicinal plant which is being cultivated commercially in India for different purposes.It has gained interest from the pharmaceutical industry; the alkaloids vincristine and vinblastine from its sap have been shown to be an effective treatment for leukemia and lymphoma. It has a great importance in studying different parameters of C. roseus. The present study was carried out for growth and bio-chemical changes of C. roseus in different elevated CO2 levels. Open top chambers (OTCs, 3.0 m diameter, 3.0 m in height) were used to expose plants to ambient and elevated CO2 concentration (600 and 900 ppm). The experiment was conducted for five months. Carbon- di- oxide enrichment studies in special open top chambers help us in understanding the changes at individual Biochemical changes and plant growth. The bio-chemical analysis revealed that the highest phenol, flavonoid, carbohydrate and tannin were recorded at 600 ppm+rh, and alkaloid was at 900 ppm. In ambient condition the highest protein was recorded in C. roseus. The plant growth revealed that the maximum fresh weight, shoot length and number of leaves were observed in 900 ppm. The maximum number of roots was observed in 600 ppm and the highest root length observed in 600+Rh. In the ambient condition, the above said characters were found to be in the lowest level.

Keywords: Catharanthus roseus, Elevated CO2, Bio chemical changes, Growth parameters.