Allelopathic Potential and Phytochemical Screening of Some Medicinal Plants of Nepal

Abstract

The laboratory tests were conducted to evaluate the allelopathic potential and phytochemical study of the four selected medicinal plants Ageratum conyzoides, Eclipta prostrata, Cannabis sativa and Woodfordia fructicosa . The aqueous extract bioassay of the plants with leaf, stem and root were conducted on the two test seeds wheat and pea by filter paper method. Germination, seedling growth and biomass production were observed under the allelopathic study wheras under phytochemical study qualitative or presence or absence and quantitative or crude amount of the phytochemicals present were also estimated. Data analysis was done by SPSS version 16. For the allelopathic studies the germination and seedling growth of wheat and pea test species under the different concentrations 2% ,4% ,6% ,8% and 10% of the leaf, stem and root extracts of the plants under study were carried out. Increased concentration of the aqueous extracts of the plants increased the inhibitory rate or decreased the germination and seedling growth. Generally leaf extract showed lower germination rate than the other parts. There was significant difference for the plumule length and rootlegth of wheat from that of control except for the radicle length of the C. sativa root extract. In pea, no significant difference was seen for A. conyzoides root, C. sativa stem and root and E. prostrata stem extract. Biomass production was maximum in W. fructicosa and least in A. conyzoides stem extracts in pea .In wheat maximum in C. sativa and minimum in E. prostrata extracts. Wheat was found sensitive to E. prostrata and W. fructicosa extracts wheras pea plant was found more sensitive to A. conyzoides and C. sativa extracts. Alkaloid, flavonoid, saponin, tannin, phenol, glycoside and essential oil were the phytochemicals present in the plant extracts.

Key words: Allelopathic potential, Phytochemical study, medicinal, bioassay, germination, seedling, biomass production, sensitive, crude