Physiological and ecological mechanisms of response and adaptation of horticultural plant resources to compound environmental stress

在各种严重的环境胁迫下，研究了园艺植物资源对紫外线b辐射和盐胁迫的响应和适应机制。通过改变UV- b照射时间、强度和波长区域等不同照射条件，研究了UV- b照射对植物的破坏作用，研究了5种蔬菜植物对UV胁迫的生理生态响应。当到达表面的UV- b被划分为波长较短和波长较长的区域时，300nm及以下的UV与可见光的增减无关，呈现出几乎固定的数量。对白菜、菠菜、番茄、茄子和萝卜分别在暗、光期进行UV-B照射，并与对照进行比较。暗期高强度UV-B使被测蔬菜叶片表面呈青铜色，叶缘向内卷曲，且c…More收缩。可见光显示出减轻UV-B照射损伤的效果。其中番茄对UV-B最敏感，280 ~ 290nm的UV-B对蔬菜产生强烈的负面影响。UV-B照射后的叶片柔韧性下降，含水量下降。对生长的影响在年轻的叶片中被强烈观察到。研究了能在高盐环境下生长的紫菀（Aster tripolium l .）营养生长期的生理反应（生长、离子吸收和水分生理）和光合作用，以阐明其耐盐机理。水分胁迫和NaCl胁迫（300mM）均降低了植株的生长，且水分胁迫下的下降幅度大于NaCl胁迫。NaCl胁迫下叶片对Na^+和Cl^+的吸收量高于水分胁迫，Na+/K+比值也较高，对照、水分胁迫、NaCl胁迫下叶片水势依次降低。膨压在对照和NaCl胁迫下基本相同，在水分胁迫下有所降低。在大气CO_2 （350 ppm）条件下，对照、水分胁迫和盐胁迫下的气孔限制光合速率分别为对照的33%、52%和44%，在没有气孔限制的情况下，水分胁迫下的光饱和光合速率降低，而NaCl胁迫下没有气孔限制。在NaCl胁迫下，气孔部分关闭限制了CO_2的供给，导致光合速率降低。而光、暗反应系统在NaCl胁迫下受到保护。同时，由于气孔关闭和暗反应系统能力下降，水分胁迫下光合速率降低。少

In various serious environmental stresses, we investigated mechanism of response and adaptation of the horticultural plant resources to ultraviolet-B radiation and salt stresses.1. By changing the various irradiation conditions such as exposure time, strength, and wavdength regions of UV-B, what kind of failure was generant to the plant by the UV-B irradiation, the physiological and ecological responses of five vegetable plant species to UV stress were investigated.When UV-B, which reaches the surface, was divided into shorter wavelength and longer wavelength regions than 300 nm, UV of 300nm or less was not related to increase and decrease of visible light, and it showed the almost fixed quantity.For cabbage, spinach, tomato, eggplant, and radish, UV-B was irradiated in the dark period, or light period, and the results was compared with the control. High-intense UV-B in the dark period made the surface of tested vegetable leaves into the bronze, and the leaf margin curled inside, and c … More ontracted. Visible light showed the effect that eases the damage by the UV-B irradiation. Tomato had the most UV-B sensitivity 280〜290nm of UV-B gave very intensive negative effects to the vegetables tested. Leaves that UV-B was irradiated had lacked the flexibility, and also decreased on the water content. The effect on the growth was strongly observed in younger leaves.2. Physiological response (growth, absorption of ions and water physiology) and photosynthesis in the vegetative growth stage of Aster tripolium L.Which was able to grow under the hyper saline environment, were investigated in order to clarify the salt tolerance mechanism.The growth lowered by water stress, and NaCl stress (300mM), and it decreased more in water stress than NaCl stress. Absorption of Na^+ and Cl^+ ino the leaves was higher in the NaCl stress than water stress, and the Na+/K+ ratio was also higher Water potential of the leaves in control, water stress, and NaCl stress lowered in order. Turgor pressure was almost same in control and NaCl stress, and lowered in water stress.Under the atmosphere CO_2 condition (350 ppm) the rates of stomatal limiting of photosynthesis in control, water stress, and salt stress were 33%, 52% and 44% of control respectively Without the stomatal limiting the light saturation photosynthetic rate was decreased in the water stress, but not in the NaCl stress. The photosynthetic rate was decreased because of limiting the supply of CO_2 through the partial closure of the stoma under NaCl stress. Light and dark reaction systems of photosynthesis, however, were protected in NaCl stress. In the meantime, the photosynthetic rate in water stress was lowered by closure of the stoma and decrease in the ability of the dark reaction system. Less