Mineral composition of Atriplex halimus plant as influenced by genotype and thermal regime.

Atriplex halimus grows in humid and saline warm regions of Mediterranean area showing high adaptability but less information is available on resistance to chilling temperatures.Potted plants of five clones (MAR1, GIO1, SAN3, PAL1, and FAN3) were cultivated during 30 months in four localities (Oristano, Tempio, Sassari, and Villasor). Every 6 months, leaves, stems and roots of plants were the object of mineral composition analysis (N, P, Na, K, Ca, Mg, Cu, Zn, Fe, and Mn). During the experiment, air temperature was recorded and hour degrees sums calculated for thresholds ranging from 0 °C to 35 °C.Leaves showed highest content of all elements, with the exception of iron.Plants showed ability to accumulate mineral elements in a synergic or antagonistic way. Accumulation of chilling hour degrees positively correlated with calcium in leaves and stems, and with manganese in the whole plant. Sodium in leaves, instead, was favored by high temperatures, which are unfavorable to nitrogen accumulation in roots. Magnesium accumulation in leaves and roots enhanced with moderately high temperatures. Two of the tested clones (GIO1 and SAN3) showed a relative low adaptability to the coldest conditions. The other three clones provided better performances with the best behavior of PAL1.