Growth, biomass production and ions accumulation in Atriplex nummularia Lindl grown under abiotic stress

ABSTRACT Atriplex nummularia is a halophyte of great importance in the recovery of saline soils and is considered as a model plant to study biosaline scenarios. This study aimed to evaluate biometric parameters, biomass production and the accumulation of ions in A. nummularia grown under abiotic stresses. Cultivation was carried out in a Fluvic Neosol for 100 days, adopting two water regimes: 37 and 70% of field capacity. Plants were irrigated with saline solutions containing two types of salts (NaCl and a mixture of NaCl, KCl, MgCl2 and CaCl2) at six levels of electrical conductivity: 0, 5, 10, 20, 30 and 40 dS m-1, arranged in a 6 x 2 x 2 factorial with 4 replicates, forming 96 plots. At the end of the experiment, plants were divided into leaves, stem and roots, for the determination of fresh matter (FM), dry matter (DM) and estimated leaf area (LA), besides the contents of Ca2+, Mg2+, Na+, K+ and Cl-. The type of salt did not influence plant growth or biomass production; however, it influenced the levels of Ca2+, Mg2+, Na+ and Cl- in the leaves and Mg2+, K+ and Cl- in the roots. Increase in salinity reduced the contents of Ca2+, Mg2+, Na+, K+ and Cl- for all treatments.

摘要：圆叶滨藜（Atriplex nummularia）是一类在盐渍土壤修复中具备重要应用价值的盐生植物（halophyte），被视为研究盐渍生境相关问题的模式植物。本研究旨在评估非生物胁迫（abiotic stresses）下栽培的圆叶滨藜的生物计量参数、生物量生产水平及离子积累特征。试验以淡色冲积新成土（Fluvic Neosol）为栽培基质，培养周期为100天，设置两种供水水平：分别为田间持水量的37%与70%。使用包含两类盐类的盐溶液（saline solutions）进行灌溉：其一为氯化钠（NaCl），其二为氯化钠、氯化钾、氯化镁与氯化钙的混合盐；盐溶液设置6个电导率（electrical conductivity）梯度：0、5、10、20、30及40 dS·m⁻¹，实验采用6×2×2三因素析因设计，设置4次生物学重复，共计96个试验小区。试验结束后，将植株划分为叶片、茎秆与根系三个组分，分别测定鲜重（fresh matter, FM）、干重（dry matter, DM）与预估叶面积（leaf area, LA），同时检测Ca²+、Mg²+、Na+、K+及Cl-的离子含量。结果表明，盐类类型对植株生长及生物量生产无显著影响，但可显著影响叶片中Ca²+、Mg²+、Na+与Cl-的含量，以及根系中Mg²+、K+及Cl-的含量；盐度升高会降低所有处理组中Ca²+、Mg²+、Na+、K+及Cl-的离子含量。