Articles
EFFECTS OF EXTERNAL AND INTERNAL FACTORS ON INCREASE OF ALKALOIDS AND STEROIDS IN SOME COMMERCIALLY CULTIVATED MEDICINAL PLANTS OF DARJEELING HILLS /WEST BENGAL INDIA/
Systematic studies on Rauvolfia serpentina have been reported by Parimoor /1974/ and Chatterjee /1977a/. Nandi and Chatterjee /1975b/ and Schieder /1978/ analysed different factors affecting alkaloid formation in Datura innoxia.
Physiological studies on Cinchona are few /Lama and Chatterjee, 1976/. Recently Chatterjee /1977b/ explained details of cultivation practices of Cinchona in India.
Chatterjee /1977a/ also reported cultivation practices of Ipecac plants growing in West Bengal.
Scientific cultivation of Dioscorea spp. and extraction of their active principles have been reported by Mehta and Staba /1970/ and Nandi and Chatterjee /1978/. Presence of Diosgenin in Costus speciosus has been reported by Dasgupta and Pandey /1970/ and developmental aspect of the plants has been analysed by Nandi /1976/. The cultivation practices of Digitalis purpurea has been mentioned by Chatterjee /1976/; that of Catharantus roseus by Chatterjee /1977a/; and of Solanum khasianum by Choudhuri and Chatterjee /1979/.
Active principles in different medicinal plants were assayed following I.P. /1955/ for Cinchona; I.P. /1955/ for Cephaelis; Selvaraj /1971/ for Dioscorea and Costus; Bakshi and Hamied /1971/ for Solanum; Reinhard et al. /1978/ for Digitalis; Schieder /1978/ for Datura; Nandi and Chatterjee /1956/ for Rauvolfia and Janot et al. /1956/ for Catharanthus.
Quantitative data on stem growth, leaf formation, branch formation, flower/fruit formation and formation of different activeprinciples were systematically collected at intervals of 15–30 days according to different species and percentage increase or decrease of different growth