Sun Jing-bo, Sun Guang-yu, Liu Xiao-dong, Hu Yan-bo, Zhao Yu-sen
College of Life Sciences, Northeast Forestry University, Harbin 150040, China.
Ying Yong Sheng Tai Xue Bao. 2009 Mar;20(3):543-8.
Taking the seedlings of mulberry (Morus alba) varieties Qiuyu and Tailai from Heilongjiang Province as test materials, this paper studied their growth, leaf water relations, and ion distribution in various organs under the stress of different salt concentration. The resu1ts showed that salt stress decreased the plant height and dry mass of the seedlings obviously, and the dry mass of young leaves was more affected than that of old leaves. With increasing salt stress, leaf water potential, osmotic potential, pressure potential, and relative water content decreased markedly, while the Na+ concentration in root and stem had an obvious increase. When the soil NaCl concentration was 150 mmol L(-1) or higher, the Na+ concentration in leaf, stem, and root reached saturated. Salt stress markedly decreased the K+ and Ca2+ concentrations in leaf, stem, and root as well as the Mg2+ concentration in leaf and stem, but had lesser effects on the Mg2+ concentration in root. The decrease of leaf Ca2+, K+, and Mg2+ concentrations under salt stress caused the ion deficiency in plant and limited plant growth, while the regionalized distribution of Na+ in root, stem, and older leaf could be one of the salt tolerance mechanisms of test varieties.
以黑龙江省秋玉和泰来两个桑树品种的幼苗为试验材料，研究了不同盐浓度胁迫下它们的生长、叶片水分关系及各器官离子分布情况。结果表明，盐胁迫显著降低了幼苗的株高和干质量，幼叶干质量比老叶受影响更大。随着盐胁迫增强，叶片水势、渗透势、压力势和相对含水量显著降低，而根和茎中Na⁺浓度明显升高。当土壤NaCl浓度为150 mmol L⁻¹及以上时，叶、茎和根中的Na⁺浓度达到饱和。盐胁迫显著降低了叶、茎和根中的K⁺和Ca²⁺浓度以及叶和茎中的Mg²⁺浓度，但对根中Mg²⁺浓度影响较小。盐胁迫下叶片Ca²⁺、K⁺和Mg²⁺浓度的降低导致植物离子缺乏并限制了植物生长，而Na⁺在根、茎和老叶中的区域化分布可能是供试品种的耐盐机制之一。
