Comparative analysis of salinity tolerance in Tamarix africana and Tamarix gallica originating from two Italian provenances.
Michael Boateng Ottie. 2019. Comparative analysis of salinity tolerance in Tamarix africana and Tamarix gallica originating from two Italian provenances. Master Thesis, University of Tuscia. Tuscia, Italy
Advisors: Prof. Paolo De Angelis and Dr. Dario Liberati
Abstract:
"In recent times, one of the starring abiotic stresses for plant survival in the ecosystem is salinity. This has resulted in massive loss of habitat, biodiversity, native vegetation and water resource value. Halophytes form 2% of plants and can tolerate 200-1000mM levels of salt concentration. Among them is Tamarix species which have been reported to be highly tolerant to salinity, occupying coastal dunes and the riverbanks of Southern Italy. They are use in the conservation and restoration practices under the perspectives of global climate changes. Different authors carried out experiments on Tamarix species, however their tolerance to salinity stresses are incompletely known or few studies reported. To address this gap, this thesis analyses the salinity tolerance in different provenances of Tamarix africana and Tamarix gallica available in the EcoPhysLab in-vivo collection. Here, we analyse the growth and physiological responses of Tamarix africana and Tamarix gallica of two Italian provenances (Simeto and Basento) over time across saline treatments (control, 200 mM, and 550 mM).
The finding of this study showed treatment effects on Tamarix species for cumulative shoot length, dominant shoot length, stem diameter and harvest biomass in both
Basento and Simeto provenances. The study shows that under control treatment, Tamarix africana had 5.2% average leaves biomass and 2.3% wood biomass more than Tamarix gallica. On the other hand, Tamarix gallica had 13.4% average leaves biomass in moderate salinity and 27% average wood biomass in high salinity more than Tamarix africana. Furthermore, Tamarix gallica had 7.5% average root biomass in control and 13.5% average root biomass in high salinity more than Tamarix africana. Under moderate, salinity Tamarix africana had 2.5% average root biomass more than Tamarix gallica. The study also indicates that Tamarix gallica had the ability to resist high saline stress as compared to Tamarix africana. Furthermore, the study also revealed physiological decline of Tamarix species in both Basento and Simeto provenances over time across moderate and high saline treatments. At the end of the experiment, the average quantity of salt accumulated outside the twigs of Tamarix species increased from 31.05 mg/g in control, to 112.21 mg/g in moderate and 169.24 mg/g in high salinity treatment. Under control, Tamarix gallica salt accumulated outside the twigs was 39.8% more than Tamarix africana. Similarly, in moderate salinity Tamarix gallica salt accumulated outside the twigs was 25.0% as well as 9.7% in high salinity more than Tamarix africana. The results of the study provide additional information about the intrinsically fascinating Tamarix africana and Tamarix gallica at both Basento and Simeto provenances in Italy as well as new insights for the conservation and restoration of potential fragile ecosystems, such as those occupied by Tamarix species. This ability has increasing potential in a world where the human population is still increasing and land use practices and changes in the climate are likely to lead to increased salinization of the land surface in many regions."
