Dynamic change of wheat eco-physiology and implications for establishing high-efficient stable agro-ecosystems under Hg stress

Heavy metal-poisoning exerts the serious influence on crops growth, yield and quality. This research has focused on the impacts of HgCl2 with different concentrations on the dynamic trends of photosynthesis, transpiration and water use efficiency (WUE) by using different wheat varieties as materials. The results showed that under 100 μM HgCl2 treatment, wheat leaf photosynthetic rate (Pn) and transpiration rate (Tr) exhibited significant changes, but photosynthetic characteristics presented no obvious regularity, and this kind of impact exerted the critical effects on different Hg2+ concentrations. Similar changes sometimes appeared under low concentration and concentrations. WUE changed more regularly, and WUE of each wheat variety tended to drop after Hg2+ treatments, except the individual concentration treatment. This change indicated that HgCl2 treatment changed normal transpiration and photosynthesis, which led to the changes in leaf water use efficiency and related wheat eco-physiological parameters. All these results provide valuable information for establishing high-efficient stable agro-ecosystems in abiotic-stress area.