【作者】 徐呈祥；

【导师】 刘友良；

【作者基本信息】 南京农业大学 ， 植物学， 2006， 博士

【摘要】 芦荟（Aloe L．）是典型的旱生植物（xerophyte），在医药、食品、日用化学品工业以及观赏园艺中具重要价值。根据生物学特性，芦荟属于淡土植物（glycophyte）而非盐生植物（halophyte）。迄今，对芦荟在盐胁迫下的响应研究很少。本文研究了库拉索芦荟（A．vera L．）对盐胁迫的响应和硅（Si）对其盐害的缓解效应，以为芦荟在盐渍化土地上的栽培和利用微咸水或再生水灌溉提供科学理论和技术支持，取得了如下结果： 以7叶龄库拉索芦荟幼苗砂培120 d的结果表明，芦荟的生长与所浇灌溶液的含盐量有密切关系。200 mmol／L NaCl显著抑制芦荟根系和叶片生长及抽葶开花，100mmol／L NaCl对其生长开花的抑制作用显著减轻，50 mmol／L NaCl处理与对照（Control）则无显著差异。盐胁迫对库拉索芦荟全叶原汁出汁率及理化性质的影响与其对生长开花的影响相似，其中50、100 mmol／L NaCl处理间多数指标值无显著性差异，与Control相比多数指标值处于有益水平。库拉索芦荟具有微咸水灌溉栽培的潜势，其耐盐性在淡土植物中属于耐盐类型，不影响芦荟生长的外界盐浓度在50-100mmol／L NaCl之间。 用0、50、100、200和400 mmol／L的NaCl处理库拉索芦荟幼苗30 d，分析了盐胁迫对其K⁺、Na⁺和Cl^-吸收、运输与分配的影响。结果表明，与Control相比，NaCl浓度≥100 mmol／L，芦荟根、茎、叶的K⁺含量显著下降，Na⁺和Cl^-尤其是Na⁺含量显著增大，K⁺／Na⁺大幅减小，AS_k，Na极显著增大，根、茎、叶中的离子平衡均受到显著干扰，但50 mmol／L的NaCl胁迫对芦荟离子吸收、运输和分配的影响较小，根、茎、叶中均可保持较好的离子平衡，相当于此一盐浓度的微咸水可直接灌溉芦荟。 不同浓度NaCl胁迫对库拉索芦荟多胺（PA）含量和状态及多胺氧化酶（PAO）活性影响的实验结果表明，NaCl胁迫24 d，芦荟根中PA含量的变化显著大于叶中，且出现时间显著早于叶中，但根和叶对不同浓度NaCl胁迫的响应差别较大。50mmol／LNaCl胁迫下，芦荟根中多胺总含量（Total PA）显著升高，NaCl浓度≥100更多还原

【Abstract】 Aloe, a typical xerophyte, is of important value in medicine and therapeutics, cosmetics, food industry, landscape and ornamental horticulture. According to biological characteristics, aloe belongs to a glycophyte rather than a halophyte. So far, available information on response of aloe to salt stress is little. In this dissertation, salt tolerance of Aloe vera L. and its relationship with exogenous silicon (Si) were studied so as to supply science theory and technique basis in aloe cultivation in saline soil or inigated with brine or weakly brine water.The experimental results of seven-leaf old A. vera cultured in sand for 120 d showed that growth of aloe was closely correlated with salt concentration in irrigated solution. The treatment of 200 mmol/L NaCl significantly retarded growth of aloe, reduced length, width, thickness, weight, water content, and chlorophyll content of its leaves, perimeter of the root system, dense radical zone, biomass of different organs and a single plant, and increased the number of withered leaves, which were even more remarkable when sodium chloride concentration reached to 400 mmol/L. However, the negative effects of salt stress on aloe growth were not very marked when sodium chloride concentration was less than 100 mmol/L as was compared with control, no NaCl added into irrigated solution, especially when the concentration of NaCl was 50 mmol/L. The effects of salt stresses between 50 and 100 mmol/L NaCl treatments on physical- chemical properties of aloe leaf juice, such as rate of leaf juice, soluble solids content, rotation viscosity, relative density, absorbance, electrical conductivity, pH value, ash percentage, total carbohydrate concentration and polysaccharide concentration were not significant. Both of the treatments produced active effects on physical-chemical properties. The external salt concentration that does not inhibite aloe growth is between 50-100 mmol/L NaCl. Based on these results, considering absorption of salt by soils, washing of rain and snow, and effect of ground water, A. vera is suitable to be irrigated with brine or weakly brine water.更多还原