K对能源植物杂交狼尾草耐盐性的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 钾对能源植物杂交狼尾草耐盐性的影响 DOI: 10.5846/stxb201301220127 作者: 作者单位: 山东师范大学生命科学学院,山东师范大学生命科学学院,山东师范大学生命科学学院,山东师范大学生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家科技支撑计划项目（2009BADA7B05）；山东省博士基金项目（BS2011SW048）；山东省科技发展计划项目（2013GNC11310） The effect of K on the salt tolerance of the bioenergy plant hybrid Pennisetum Author: Affiliation: Key Laboratory of Plant Stress,College of Life Science,Shandong Normal University,Key Laboratory of Plant Stress,College of Life Science,Shandong Normal University,Key Laboratory of Plant Stress,College of Life Science,Shandong Normal University,Key Laboratory of Plant Stress,College of Life Science,Shandong Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以盆栽的杂交狼尾草（Pennisetum americanum ×P. purpureum）为实验材料，在不同浓度NaCl（0%，0.5%）条件下，用含有不同钾浓度（0.1，3，6，9 mmol/L）的营养液处理4周后，测定植株高度、分蘖数、干重、叶片净光合速率、不同部位的离子含量、MDA（丙二醛）含量和细胞质膜透性等生理指标，以确定缓解盐害的适宜钾浓度。结果表明：0.5% NaCl明显抑制了杂交狼尾草幼苗的生长和光合。在0.5% NaCl处理下，随着钾素浓度增加，杂交狼尾草的生物量显著增加，其中6 mmol/L的钾显著降低杂交狼尾草所受盐害，即6 mmol/L的钾素处理缓解了NaCl对杂交狼尾草株高、分蘖数、干重、光合速率的抑制；降低了杂交狼尾草叶片的MDA含量和质膜透性；降低了功能叶的Na+含量，增加了K+含量，从而增加了功能叶的K+/Na+。以上结果表明，适宜的钾浓度（6 mmol/L）能明显缓解NaCl对能源植物杂交狼尾草生长和光合的抑制。这些结果为在盐碱地上大面积种植杂交狼尾草时合理施用钾肥提供了理论依据。 Abstract:More than 6% of the world's total land area is impacted by salt. Most cultivated plants are sensitive to salt stress, and NaCl salinity, which results in ionic disturbance, osmotic and toxic effects, and which usually causes a great reduction in vegetative growth, rate of photosynthesis and an imbalance in plant nutrient uptake. Potassium (K) deprivation resulting from NaCl salinity, is expected to have a large and rapid negative effect on the rate of leaf expansion and final growth. Potassium (K), as one of 17 essential elements required for plant growth, participates in an array of processes, for example, potassium ions can be used as an activator for 60 different enzymes, promote photosynthesis, facilitate the transport of photosynthetic products, regulate the water potential of plant cells and stomatal movement. Plants subjected to salt stress are particularly prone to K deciency as within saline soils there may be less available K due to reduced K diffusion and poor root uptake. Therefore, K is frequently the main limiting element for plant growth and development during the ecological transformation of saline impacted land. Hence, the reasonable application of K fertilizers is the recommended treatment for enhancing soil K availability, stimulating plant yields and avoiding the deterioration of saline land. Hybrid pennisetum (Pennisetum americanum×P. Purpureum) is now widely regarded to have substantial potential as a bioenergy plant and a forage source for livestock production. It has been characterized by good stress resistance, fast growth and high yields. Hence, hybrid pennisetum is a suitable energy plant candidate for the transformation of coastal areas, which are considered as suitable sites for cultivation of energy plants, since they are widespread and cannot usually be used as farmland due to the high soil salinity. Therefore, in order to better guide the establishment of the bio-transformation of the Yellow River Delta saline lands using this potential energy plant, the effects of K nutrition on growth, photosynthesis and ion accumulation of the energy plant hybrid pennisetum, seedlings were examined under saline conditions. In a pot experiment, we investigated the effects of K+ level on seedling growth, ion concentrations in leaves and roots, photosynthetic characteristics, MDA (malondialdehyde) concentration and membrane permeability in the leaves of the hybrid pennisetum, under 0.5% NaCl to determine suitable levels of potassium supply to alleviate the salt damage of the studied species. The results showed the growth and photosynthesis of hybrid pennisetum seedlings were significantly inhibited under 0.5% NaCl conditions. However, the dry weight of shoots and roots, plant height and tillering number were significantly increased with the addition of K+, especially for 6 mmol/L of K+ under 0.5% NaCl. K+ supply significantly reduced the inhibitive effect of NaCl on plant height, tillering number, dry weight of shoot and root, and photosynthesis. The K+ supply also decreased the MDA concentration and membrane permeability, decreased the concentration of Na+ and increased the concentration of K+, markedly improving the K+/Na+ ratio of functional leaves. The results indicated that a supply of suitable concentrations of K+ (6 mmol/L) can significantly alleviate the inhibition of growth and photosynthesis caused by salinity in hybrid pennisetum. These findings would provide a theoretical basis for practical application when large-scale cultivation of hybrid pennisetum occurs on saline land. 参考文献 相似文献 引证文献