Adaptability of species of thegenus Atriplexto different thermic regimes

A very effective tool to combat desertification is rivegetation. Promising species for this purpose are the evergreen shrubs of thegenus Atriplex. The purpose of the research is to study the various physiological responses ofA. halimusto thermic stress and to select clones resistant to low temperatures. The test was conducted in 4 sites in Sardinia characterized by different environmental conditions. In every site five clones ofA. halimuswere compared. After a period of acclimatization, the growth of plants in terms of linear growth of the biomass was measured. In the same periods, the fresh and dry biomass amount per plant were determined, as well as the content of the main macro and microelements. Correlations between the index of cumulated cold (ICC), which consists of the sum of the degrees of differences between the average daily air temperature and the thresholds of critical temperatures of 0, 5 and 10 °C, and the various parameters were analyzed. Differences among the five clones, with regard to the influence of low temperatures on plant growth, on the production of biomass, and on accumulation of macro and microelements were evaluated. Among the five clones tested, the clone GIO1 and SAN3 resulted more sensitive to temperature. The clones MAR1, PAL1 and FAN3 resulted less sensitive to low temperatures and also in the site characterized by the lowest minimum temperatures have shown greater adaptability, and thus a positive growth.