Unraveling the cumulative effect of soil- applied radiation-processed sodium alginate and polyacrylamide on growth attributes, physiological activities, and alkaloids production in periwinkle [catharanthus roseus (L.) G. Don]

Abstract

Cancer has taken millions of lives in the passing decade alarming the scientists to urgently design the magic bullets for this jeopardy. Catharanthus roseus (L.) G. Don reportedly emerged as a remedy to this problem contributing, medicinal system, two of its paramount anticancer alkaloid constituents, vincristine and vin- blastine. Recently, a new agro-technique has been evolved in which gamma- irradiated natural polysaccharides (e.g., alginate, carrageenan, and chitosan) are degraded into oligomers. When these oligomers are applied through foliar applica- tion to the plants, it proves as potent plant promoter. On the other hand, for quality soil structure, polyacrylamide (PAM) is used whose application to the soil contrib- utes a great deal in terms of stability to soil and increased water holding capacity. A pot experiment was conducted to study the effect of soil-applied polyacrylamide (PAM) and irradiated sodium alginate (ISA) alone or in combination on C. roseus. The plants were harvested at 90 days after transplanting (DAP). Of the six treat- ments [(i) water sprayed control (Treatment 1), (ii) un-irradiated sodium alginate (UISA) (Treatment 2), (iii) irradiated sodium alginate (ISA) (Treatment 3), (iv) PAM (Treatment 4), (v) UISA + PAM (Treatment 5), and (vi) ISA + PAM (Treatment 6)] increased the values of most of the parameters significantly including fresh and dry weights of plants, contents of nitrogen, phosphorus and potassium, chlorophyll and carotenoids content, and activities of carbonic anhydrase and nitrate reductase in the leaves. The combined application of ISA + PAM also increased total content and yield of leaf alkaloid by 14.1% and by 40.2% over the respective controls. Conclusively, the technique seems economically and ergonomically successful in increasing the expensive alkaloid production of C. Roseus.