Title : The Effect of enhanced solar UV-B (280-320 nm) radiation on morphology, photosynthetic pigment synthesis, and accumulation of bioactive compounds in some medicinal plants
UV-B is the primary environmental factor in tropical region to stimulate growth, development and induction of secondary pigment synthesis in medicinal plants. The studies on UV- in medicinal plants are very less particularly with respect of UVB induced bioactive compound in plants. In the present study, the traditional medicinal plants like Achyranthes, Acalypha and Phyllanthus were subject to UV-B radiation under field condition and assessed the harmful effect on morphology, photosynthetic pigment synthesis and accumulation of bioactive compounds at different ages. There is no significant changes were seen the morphology of the plants. Rather than negative effect the UVB radiation to promote the growth of Phyllathus from early to later stages of the plant. Whereas, in Acalypha and Achyranthes in early stage showed slight inhibition but later stage it recovers from such inhibition and lead to a normal life. The chlorophyll and carotenoid synthesis did not demonstrate any significant impact by UV-B. The phytochemical analysis of dried leaf methanol extracts of individual plant showed the presence of flavonoids, anthocyanin, alkaloids, phytosterol, saponin, tannin and steroids. Further examination of TLC also reveled quantitative and qualitative difference in bioactive compound profile. They were additionally confirmed by few significant chromatographic peaks of GC-MS analyses. This examination inferred that the UVB stress is a more intense factor to increasing concentration of active components in medicinal plants. In future the UVB induced bioactive components is more essential potential herbal drug for human healthcare.