Laboratory experiments were conducted to study the effect of the aqueou extract of the
vegetative parts of the Euphorbia paralias at different concentrations (2%,4%,8%) in seed
germination and seeding growth of the Lepidium sativum, Lactuca sativa
and
Portulaca oleracea. The results indicated increase in germination ratio of Portulaca
oleracea. up to 7%. while the effect of the extract was not evident in the germination of the
seeds of Lepidium sativum, and decreased the germination ratio of Lactuca sativa
seeds by 35.9% at the concentration of 8%.In contrast, the extracts stimulated the length of
the stalks of Portulaca oleracea , Lepidium sativum and Lactuca sativa plants at all
used concentrations used. The highest rate of stimulated stalks legnth of Lepidium
sativum at 2% was 58.2%. inhibitory effect of water extract observed for root length of
Portulaca oleracea and Lactuca sativa plants at 2% , and stimulation effect pour
Lepidium sativum, The effect became evident at the concentrations of 4% and 8% for the
three plants.
The most sensitive and affected plants was Portulaca oleracea, where the length of the
root decreased by 53.38% at the concentration of 4% and by 72% at the concentration of
8% ,while the length of the root Lepidium sativum and Lactuca sativa decreased by
25.82% and 34.95% was decreased for 4% and 8%respectively.
The results suggested that this weed may affect seedling growth, due to inhibitory or
stimulatory effect of Allelochemicals , which present in water extract of this weed . and
may used as potential Bioherbicide after further experiments.
Bioeffect of some Syrian Myrtus communis L. leaves extracts in growth of some pathogenic microorganisms, which were isolated from Al-Assad hospital laboratory in Lattakia, was tested by disc diffusion method. Results showed that cold and hot water ex
tracts have antibacterial activity against all Gram positive and negative bacteria, and pathogenic Candida albicans except Klebsiella pneumoniae. All organic extracts have antibacterial activity against Proteus vulgaris, Entrococcus faecium, Staphylococcus aureus and Staphylococcus albus.
Pseudomonas aeruginosa and Pseudomonas fluorescens were affected by most of the organic extracts, and the most bioactivity was by methanol extract, and all inhibition zones of extracts were bigger than inhibition zones by control
antibiotics. Serratia marcescens and Acinetobacter calcoaceticus were affected by methanol (with highest inhibition zone 37.33 and 27.33 mm respectively), ethanol, acetone and ethyl acetate extracts, but resistant to the others. Klebsiella pneumoniae affected by ethanol extract only with inhibition zone 20.33 mm.
Results of bioactivity according to a various solvents used in this study demonstrate that Syrian Myrtus communis L. leaves extracts have antimicrobial activity, so expected to be potential sources of natural antibacterial and antifungal products against some pathogenic bacteria and fungi in the future.
