Abstract
The present study intended to investigate the effect of aqueous extract from Calotropis procera L. on growth of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and some pathogenic microorganisms (Escherichia coli L. and Staphylococcus aureus R.) by the laboratory experiments. Also, phytochemical screening of aqueous extract of C. procera was qualitatively tested for the presence of some bioactive compounds (alkaloids, phenolics, flavonoids, tannins, saponins, sterols and terpenoids). Results showed that higher concentrations of C. procera extract (7% and 10%) significantly reduced germination percentage, radicle length and plumule length of wheat as compared to control. In contrast, the aqueous extract had not effect on seed germination percentage of barley but had a great inhibition effect on length of radicle and plumule. Also results showed that aqueous extract of C. procera effect on the pathogenic microorganisms Escherichia coli L. and Staphylococcus aureus R. in which there was a marked increase inhibition in growth of two microorganisms with the higher concentration. The main component of C. procera may be phenolics compound and flavonoids that may be responsible for their action on seed germination of the studied plants and growth of two tested microorganisms.