Benyahia, Mohammed Elsseddik, Allal, Farida, Mallem, Hamida, Louassa, Samira, Houyou, Zohra, and Bendouma, Amal
The Algerian steppes face ecological imbalances due to overgrazing, cereal cultivation, and resource pressure. In response, the government implemented the "Great Works for the Development of Steppe Pastures" program in 1994, planting the nonnative Atriplex canescens, a shrub resistant to cold, drought, and salinity. However, introducing exotic plants can harm native biodiversity through allelopathy interaction. This work aims to test the allelopathic potentiel of A. canescens on the most representative North African steppe plant Macrochloa Tenacissima. Phytochemical tests are performed on the aerial parts of these two plants. Aqueous extracts are prepared from the aerial parts of A. canescens with three concentrations respectively T0 (0%), T1 (2.5%) and T2 (5%), and are applied in situ for 45 days on M. tenacissima plants. The response of M. tenacissima to the extract of A. canescens is monitored by measuring chlorophyll and proline in the fresh leaves of the target plant M. tenacissima. The results showed the presence of allopathic molecules in the aerial parts of both plants, notably Alkaloide, flavoniode, tannins, triterpnoide, Quinon and phenolic acid. The response of M. tenacissima to the application of A. canescens extract caused during the trial remarkable change in the total chlorophyll content of M. tenacissima, with reductions of 1 to 4 (mg/g FM) observed at the end of 45 days of application. The highest decrease is observed for treatment T3. After 45 days of treatment with A. canescens extract aqueous, M. tenacissima showed the highest proline accumulation 2.6 (mmol/g MF) for the treatment T3. Our findings show that A. canescens can induce physiological disruptions in M. tenacissima. [ABSTRACT FROM AUTHOR]