Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu, Sichuan, China.
College of Mechanical and Electrical Engineering, Sichuan Agricultural University, Chengdu, Sichuan, China.
Environ Monit Assess. 2018 Feb 6;190(3):119. doi: 10.1007/s10661-018-6481-1.
To determine whether the melatonin (MT) could reduce cadmium (Cd) accumulation in Cyphomandra betacea seedlings, different concentrations of MT were added to the nutrient solution and soil to study its effects on the growth and Cd characteristics of C. betacea seedlings. Fifty micromoles per liter (μmol/kg) of MT increased the biomass of C. betacea seedlings, but 100-200 μmol/L (μmol/kg) MT decreased seedling biomass in both the nutrient solution and soil cultivation experiments. The photosynthetic pigment contents showed no significant changes compared with the control when the MT dose was 150 μmol/L (μmol/kg) or less, while 200 μmol/L (μmol/kg) MT decreased the photosynthetic pigment contents. Low levels of MT improved the antioxidant enzyme activities of C. betacea seedlings, whereas high MT levels reduced them. MT increased the Cd contents in different organs of C. betacea seedlings in the nutrient solution cultivation experiment, but only 50 μmol/kg MT increased the Cd contents in stems, leaves, and shoots of C. betacea seedlings in the soil cultivation experiment. Therefore, only low levels of MT can promote the growth of C. betacea seedlings, and MT is not suitable for reducing Cd accumulation in C. betacea seedlings.
为了确定褪黑素（MT）是否能降低番石榴幼苗中镉（Cd）的积累，将不同浓度的 MT 添加到营养液和土壤中，研究其对番石榴幼苗生长和 Cd 特性的影响。50 微摩尔每升（μmol/kg）的 MT 增加了番石榴幼苗的生物量，但在营养液和土壤培养实验中，100-200 μmol/L（μmol/kg）的 MT 降低了幼苗的生物量。当 MT 剂量为 150 μmol/L（μmol/kg）或更低时，与对照相比，光合色素含量没有明显变化，而 200 μmol/L（μmol/kg）的 MT 降低了光合色素含量。低水平的 MT 提高了番石榴幼苗的抗氧化酶活性，而高水平的 MT 则降低了它们的活性。MT 增加了营养液培养实验中番石榴幼苗不同器官的 Cd 含量，但只有 50 μmol/kg 的 MT 增加了土壤培养实验中番石榴幼苗茎、叶和嫩枝的 Cd 含量。因此，只有低水平的 MT 才能促进番石榴幼苗的生长，而 MT 不适合降低番石榴幼苗中 Cd 的积累。
