Allelopathic Effects of Shoot and Root Extracts From Three Alien and Native Chenopodiaceae Species on Lettuce Seed Germination

One basic method of improving rangelands in the country is the use of native as well as exotic species of adaptable plants. Some species of Atriplex, like Atriplex canescens and Atriplex nummularia has been introduced in many thousands hectares of rangelands since more than 20 years, it feeds some debates on the algerian scientific community, so that’s why it is important to know the impact and necessary to consider its effects on native species. In the current study the effect of chemical competition of Atriplex canescens and Atriplex nummularia comparing to native Atriplex halimus by observing the effect of aqueous extracts of leaves, stems and roots of the three chenopod species assayed at 0.06, 0.63, 1.55, 3.12 and 6.25 g /l on the germination of lettuce seed test. Seed germination was significantly inhibited by shoot alien species extracts especially A.nummularia at concentrations ranging from 1.55 to 6.26 g/l with decrease rate of 20% in the lettuce seed tests indicating the presence of allelopathic substances, in 0,06 the germination increased to more than 10% comparing to the water irrigated seeds. An opposed effect than the expected had been found because Atriplex canescens had a less allelopathic effect than our native plant Atriplex halimus