Hatamian Mansoure, Nejad Abdolhossein Rezaei, Kafi Mohsen, Souri Mohammad Kazem, Shahbazi Karim
Dept. of Horticultural Sciences, Faculty of Agriculture, Lorestan University, Khorramabad, Iran.
Dept. of Horticulture, University of Tehran, Karaj, Iran.
Heliyon. 2020 Jan 18;6(1):e03247. doi: 10.1016/j.heliyon.2020.e03247. eCollection 2020 Jan.
The environmental toxicity of heavy metals in particular cadmium is a public concern. Cadmium is toxic for all living organisms including plants; however, plant species may show different tolerance to the presence of cadmium in their root medium. Adopting practical strategies may reduce cadmium bioavailability or increase the plant tolerance. In the present study, interaction of nitrate was investigated on cadmium treatment in hackberry ( L.) seedlings. Different levels of nitrate (0, 50 and 100 mg/L) and cadmium (0 and 5 mg/L) were applied to seedlings via irrigation water during two consequence years. The treatments were arranged in a factorial with completely randomized design in four replications. The results of ANOVA showed that the cadmium-nitrate interaction was significant on leaf Cd concentration and root dry weight at P = 0.01, and on carotenoids and leaf dry weight at P = 0.05, while it was not significant on the rest of traits. Application of cadmium had no significant effect on new shoot growth, leaf chlorophyll and leaf fresh weight; however, it significantly reduced stomatal water conductance and photosynthesis rate, while it increased leaf transpiration rate, root and stem fresh weights, leaf Cd and proline concentrations. Application of nitrate levels, on the other hand, constantly increased the leaf nitrate concentration, new shoot growth, leaf fresh and dry weights, root fresh weight, stomatal water conductance and photosynthesis rate, whereas it reduced the necrotic points of leaves. The results indicated that the growth characteristics of hackberry seedlings were mainly influenced by nitrate but not cadmium application, and this ornamental tree is a tolerant species to high soil Cd levels.
重金属尤其是镉的环境毒性是一个公众关注的问题。镉对包括植物在内的所有生物都有毒性；然而，不同植物物种对其根部介质中镉的存在可能表现出不同的耐受性。采取切实可行的策略可以降低镉的生物有效性或提高植物的耐受性。在本研究中，研究了硝酸盐对朴树（ Celtis sinensis Pers.）幼苗镉处理的影响。在连续两年中，通过灌溉水向幼苗施加不同水平的硝酸盐（0、50和100毫克/升）和镉（0和5毫克/升）。处理采用析因设计，完全随机排列，重复四次。方差分析结果表明，镉 - 硝酸盐相互作用对叶片镉浓度和根干重（P = 0.01）、类胡萝卜素和叶片干重（P = 0.05）有显著影响，而对其他性状无显著影响。施加镉对新梢生长、叶片叶绿素和叶片鲜重没有显著影响；然而，它显著降低了气孔导水率和光合速率，同时提高了叶片蒸腾速率、根和茎的鲜重、叶片镉和脯氨酸浓度。另一方面，施加不同水平的硝酸盐持续增加了叶片硝酸盐浓度、新梢生长、叶片鲜重和干重、根鲜重、气孔导水率和光合速率，同时减少了叶片的坏死点。结果表明，朴树幼苗的生长特性主要受硝酸盐影响，而非镉的施加，并且这种观赏树是对高土壤镉水平具有耐受性的物种。
