【作者】 夏天翔；

【导师】 刘兆普；

【作者基本信息】 南京农业大学 ， 植物营养学， 2004， 硕士

【摘要】 本试验由温室盆栽耐盐耐旱试验和大田海水灌溉试验两大部分组成：温室盆栽试验主要通过砂培的方法，研究了幼苗期菊芋在盐分和水分胁迫下的生理反应；大田试验在半干旱的山东莱州地区进行，研究了海水灌溉对菊芋及其土壤的影响。结果如下： NaCl处理下菊芋幼苗叶片无机离子总含量急剧增加，其中Na⁺、Cl^-增加最多，占总计算渗透势（COP）的52-68％，总无机离子占COP的95-97％。而有机溶质总含量则稍有降低，约占COP的3-5％。PEG处理的无机离子含量高于对照，但低于等渗NaCl处理，有机溶质含量却都低于对照和等渗NaCl处理。结果还表明，随着NaCl浓度的递增，菊芋幼苗叶片电解质渗透率和丙二醛含量呈上升趋势；PEG处理下，电解质渗透率和丙二醛含量与对照无明显差异，但明显小于等渗NaCl处理。并且，菊芋幼苗叶片中Na⁺、Cl^-含量的增加与电解质渗透率和丙二醛含量增大均呈正相关，其中电解质渗透率的增大与Na⁺、Cl^-含量的增加达到显著水平。 NaCl和PEG胁迫下，根、茎、叶的Na⁺、Cl^-含量不断升高，而K⁺含量保持稳定。其中，茎中Na⁺含量高于根和叶。NaCl胁迫下，根、茎、叶的S_K,Na值随胁迫强度的增加而递增，茎中S_K,Na值小于根和叶。随着NaCl胁迫强度的增加，菊芋幼苗叶片的SOD和POD活性先上升后下降；PEG处理下，SOD活性分别高于对照和等渗NaCl处理31.1％和27.1％；而POD活性却分别低于对照和等渗NaCl处理26.0％和36.1％。 海水灌溉下，菊芋的茎部具有明显的贮Cl^-、Na⁺能力，在高浓度海水灌溉下菊芋整个植株对K⁺具有较高的选择吸收性；菊芋地上部和块茎产量在30％海水处理范围内，没有减产趋势，在50％海水灌溉下减产幅度分别为37％和32％；可见，正常自然条件下的海水灌溉，对产量的影响主要和灌溉水的浓度有关，但只有在50％处理下才显著减产，低于50％产量并无差异。利用海水资源对菊芋进行灌溉不影响其块茎中菊糖的含量，菊芋块茎中菊糖含量范围为40％到65％左右。 海水灌溉下，耕层土壤中盐分含量受降雨量影响很大，足够的降雨条件下，盐分不会积累，降雨量较低时，盐分积累明显，但在50％海水处理下趋于平衡状态；耕层土壤SAR值的变化情况和盐分含量变化情况相一致，在灌溉水中海水浓度大于50％时有所下降；土壤中主要盐离子为Cl^-和Na⁺，0-60cm土层内，Na⁺、Cl^-明显的向土壤底层迁移，其在土壤中的含量受降雨影响显著，而Ca²⁺、Mg²⁺和K⁺在土壤中迁移能力较低，其含量受降雨影响较小；0-60cm层次土壤盐分的纵向分布在降雨量较低的条件下主要受灌溉水中海水浓度的影响，而在降雨充分的条件下，地面覆盖程度成为重要的影响盐分和水分胁迫下菊芋的生理响应及其海水灌溉研究因子之一。更多还原

【Abstract】 My experiment can mostly include two sections: the first one was a pot experiment which was carried out in the greenhouse to study the physiological responses of Helianthus tuberosus L. seedlings to salt and water stress; the second one was a field experiment which was carried out in Laizhou, Shandong Province to study the effects of seawater irrigation on Helianthus tuberosus L. and soil. The results were as below:Under NaCl stress, the sum of inorganic ions had a significant increase and their contribution to the calculated osmotic potential (COP) was up to 95-97%. The great increase of Na+ and Cl- content accounted for 52-68% of COP, whereas the total content of organic solutes decreased slightly and their contribution to COP was about 3-5%. Under water stress, the content of inorganic ions were higher than that of CK, but lower than that of iso-osmotic NaCl treatment. Otherwise, the content of organic solutes were lower than that of both CK and iso-osmotic treatment under water stress. The results also showed that with the increasing of NaCl concentrations, both the electrolyte leakage and the content of MDA increased. And under water stress, both the electrolyte leakage and the content of MDA had no significant difference compared with those of CK, but were lower than those of iso-osmotic NaCl treatment. Furthermore, the content of Na+ and Cl- in the leaves was positively correlated with the electrolyte leakage and the content of MDA of leaves, and the correlation levels of the content of Na+ and Cl" and the electrolyte leakage are significant.Under NaCl and PEG stresses, the content of Na+, Cl- in root, stem and leaf increased but the content of K+ had no significant changes. The content of Na+ in stem is higher than that in root and leaf. With the concentration of NaCl increasing, the selective adsorption of K+ and Na+ (SK,Na) for root, stem and leaf gradually increased, and SK,Na for stem was lower than that for root and leaf. With the concentration of NaCl increasing, activities of SOD and POD in leaf increased at first then decreased As compared with under condition of control treatment and iso-osmotic NaCl stress, under PEG stress SOD activities in leaf increased 31.1% and 27.1%, but POD activities decreased 26.0% and 36.1% respectively.The stem of Helianthus tuberosus (L.) had the ability of containing high contents of Na+ and Cl-, and selectively absorbed K+ in high proportions seawater irrigation; The above and tubers yields of Helianthus tuberosus (L.) hadn’t decreased until at the 50% proportions seawater irrigation where the yields decreased by 37% and 32% in contrast tofreshwater-irrigated. It meant that through natural weather, reduction of yields was occurred by salinity of irrigation water but the reduction was not significant until the proportions of seawater in irrigation water were the same as 50% or above it. The irrigation with seawater hadn’t affected the inulin contents hi Helianthus tuberosus (L.) tubers, and the contents of inulin in Helianthus tuberosus (L.) were from about 40% to 65%.Salt contents hi root zone soil were greatly influenced by rainfall. Salt buildup did not exist on the condition of enough rainfall, on the contrary salt accumulated obviously on the condition of low rainfall in the root zone soil. But on the later condition the trend of accumulation turned to be stable in the W3 treatment (Vseawater/ V Pure water=1)- In root zone soil, variation of SAR value accorded with total salt accumulations and sometimes decreased at the treatment where the V seawater/ V pure water>1. Contents of Cl- and Na+ which were the main ions and leached obviously in 0-60cm soil were greatly influenced by rainfall, but the rainfall did not affected the contents of Ca2+, Mg2+ and K+ whose ability of leaching is worse than that of Cl- and Na+ in the root zone soil obviously. The vertical distribution of salt ions in the 0-60cm soil were mainly affected by the ratio of V seawater/ V pure water in the irrigation water on the condition of not enough rainfall, but on the cont更多还原