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41.
The effects of exposure to UV-B radiation,280-315 nm,and dark or dark repair conditions on the early development of Chondrus ocellatus Holm collected from Qingdao coast were studied under the laboratory condition.After being exposed to different doses [0,36,72,108,144 and 180 J/(m 2 · d)] of UV-B radiation,one treatment of tetraspores were put back to normal culture condition (PAR),the other treatment were put into dark condition to repair for 2 h.During the cultivation,the diameter of the tetraspores were recorded every 4 d till the 50th day when vertical branches formed in all treatments.Then at the 50th day,CPDs,phycoerythrin,chlorophyll a and MAAs (Palythine and asterina-330) were measured.The results showed that low doses UV-B radiation could significantly accelerate the growth rate of the tetraspores of C.ocellatus and the growth rate reduced gradually with UV-B radiation keep on increasing.The variation trend of both the phycoerythrin and chlorophyll a concentration reduced significantly ( P < 0.05) once given the UV-B radiation. Under UV-B stress,the CPDs were induced,and the concentrations of CPDs were significant low in dark repair groups.The data of MAAs analyzed by LC/MS in the tetraspores of C. ocellatus suggested that there were two MAAs formed (palythine and asterina-330) after UV-B radiation induced, and low dose of UV-B irradiation could significantly induced the concentration of MAAs.From the growth and development state of the tetraspores,negative effects of UV-B radiation on the dark repair groups were more serious than PAR. 相似文献
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采用实验生态学的方法,研究了3种多环芳烃-菲、芘和蒽对3种赤潮微藻-赤潮异弯藻、亚历山大藻和中肋骨条藻光合速率的影响。结果表明:较低浓度的菲、芘和蒽处理使3种赤潮微藻的光合速率有所提高,而较高浓度处理则降低了藻细胞的光合速率。3种多环芳烃-菲、芘和蒽胁迫对赤潮异弯藻光合速率的96h·EC50分别为0.089、0.110和0.124mg·L-1,对中肋骨条藻的96h半抑制剂量分别为0.103、0.127和0.138mg·L-1,对亚历山大藻的96h半抑制剂量分别为0.116、0.131和0.141mg·L-1,说明3种多环芳烃对赤潮微藻均表现出一定的毒性效应,其中菲的毒性作用最强。UV-B辐射(0.3J·m-2的辐射剂量)和多环芳烃的联合作用一方面增强了菲、芘和蒽对3种赤潮微藻光合效率的抑制作用,导致光合速率明显降低,另一方面在一定程度上改变了3种多环芳烃毒性作用的强弱,使芘的毒性作用变得最强。 相似文献
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LIUQing TerryV.Callaghan ZUOYuanyuan 《山地科学学报》2004,1(3):276-288
In the last three decades much research has been carried out to investigate the biological effects of a thinning stratospheric ozone layer accompanied by an enhanced level of solar ultraviolet-B radiation at the Earth‘s surface.Enhanced UV-B radiation affects ecosystems in many ways directly and indirectly. The responses can be biochemical, physiological, morphological or anatomical, and the direction of the response can vary between different species, communities and ecosystems. In this paper we firstly introduce general concepts, and methods for measuring the ecological effects of UV-B radiaticn. Secondly, we provide an overview interpretation of the effects of enhanced UV-B on terrestrial ecosystems from recent studies.These studies include effects of UV-B on growth and reproduction, composition of communities,competitive balance, decomposition of litter, and interactions with other factors etc. Finally, we recommend future research directions to identify the effects of elevated UV-B radiation on ecosystems in China. 相似文献
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Based on 1999-2000 observations made by the first Arctic and sixteenth Antactic scientificvoyages,a study is undertaken about the meridional surface UV-B (B band ultraviolet rays)variations in 75°N-70°S.It is mitigated as a function of latitudes and marked by lower radiationaveraged over the Northern Hemisphere (NH) than over the Southern Hemisphere (SH),with itsdaily course basically similar to that of total radiation.Around polar summer noon hours (localtime) and where ice albedo is maximum,the strongest UV-B irradiance on the surfaceperpendicular to sun's beams as found at equatorial latitudes is measured sometimes.In the areasnear Zhongshan Station the increase of surface UV-B radiation shows a close relation to thedecrease of ozone in the higher atmosphere but it has a less intimate relation with its concentrationat ground. 相似文献
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Impairment of sea urchin sperm quality by UV-B radiation: predicting fertilization success from sperm motility 总被引：4，自引：0，他引：4
Sperm quality of the sea urchin, Anthocidaris crassispina, after exposure to environmentally realistic UV-B irradiances, was assessed by changes in sperm motility (measured by the computer-assisted sperm analysis (CASA) system), and related to subsequent fertilization success. Percentage motile sperm of A. crassispina declined significantly after exposure to a UV-B dose of 16.2 kJ m(-2), while sperm motion velocity as measured by curvilinear velocity (VCL), straight line velocity (VSL), and average path velocity (VAP) showed significant reduction after exposure to a UV-B dose of 5.4 kJ m(-2). A parallel study showed that fertilization success was significantly reduced after sperm were exposed to UV-B doses > or = 5.4 kJ m(-2). Notably, the four sperm motility parameters were strongly correlated with fertilization success (P < 0.001), followed the increasing order: VSL (r = 0.8) < % motile sperm (r = 0.804) < VCL (r = 0.912) < VAP (r = 0.928). Fertilization success is best predicted by VAP using the exponential model: y = 8.678 + 90.202/[1 + exp(82.83 - x)/10.27)] (r(2) = 0.95). Thus, impairment of sperm motility of sea urchin, as measured by the CASA method, can be used to predict reproductive success and ecological effects. 相似文献
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A Possible Photochemical Link Between Stratospheric and Near-Surface Ozone on Swiss Mountain Sites in Late Winter 总被引：2，自引：0，他引：2
Record high near-surface ozone concentrations at two elevated sites (Chaumont, 1140 m asl, and Rigi, 1030 m asl) in Switzerland were observed simultaneously with extremely low total ozone during a fair weather period in mid-February 1993. An analysis of ozone, temperature, humidity, and wind profiles suggests that the surface ozone peaks were most possibly generated within the region in a layer between about 1000 and 1500 m asl. Mean diurnal cycles of ozone concentration during the period shows a strong increase from late morning to late afternoon at Chaumont and at the same time a decrease at the high alpine site Jungfraujoch (3580 m asl). The different diurnal ozone cycles can both be explained photochemically by taking into account the large difference in NOx concentrations (about two orders of magnitude) between the sites. Photochemical processes are also indicated by the diurnal cycles of NO2 and NO concentration. As a strong photochemical activity is not expected in mid-February at 47°N, we hypothesize that the extremely low total ozone played a role. Total ozone controls the amount of UV-B radiation reaching the troposphere and thus influences photochemical processes. Using a radiation model, we calculated an increase in ozone photolysis at Chaumont and Jungfraujoch of 73% and 83%, respectively, on the day with the lowest total ozone (243 DU) compared to average February conditions (335 DU). It is suggested that total ozone changes have the potential to stimulate photochemistry sufficiently to produce the observed surface ozone peaks at Chaumont and Rigi of 61 and 64 ppbv, respectively. A fog layer just below Chaumont during these days probably also influenced photochemistry, but on a smaller spatial scale. Our empirical results on the influence of changing UV radiation on tropospheric photochemistry are in close agreement with model studies of other groups. Although this case study represents unique conditions, a distinct anticorrelation between near-surface ozone at Chaumont and total ozone also appears in other years (1992–1997) when selecting fair weather days in mid-February. However, other influences cannot be excluded. The selected days provide evidence of a significant photochemical source of ozone in the mid-latitude lower troposphere in late winter. 相似文献
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UV-B辐射和久效磷对三角褐指藻DNA共同伤害效应 总被引：1，自引：2，他引：1
运用生态毒理学和生物化学的方法研究了紫外线和久效磷对三角褐指藻DNA的伤害作用。结果表明 ,久效磷对三角褐指藻的生长有抑制作用 ;随着久效磷浓度的增加 ,三角褐指藻DNA损伤程度增加 ;在久效磷浓度固定不变时 ,随着处理时间的延长 ,DNA的损伤程度同样提高 ;在久效磷的处理过程中同时伴有紫外线的辐射处理 ,DNA的损伤程度加剧 ;久效磷处理解除一段时间后 ,DNA损伤程度未明显减轻 ,而UV B处理解除后 ,DNA的损伤可明显恢复。说明DNA的损伤可在一定程度上指示海洋微藻受久效磷伤害的的程度。 相似文献
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采用共培养的方法,研究了塔玛亚历山大藻和中肋骨条藻种群竞争关系对UV-B辐射增强的响应变化.结果表明,不同的接种密度对塔玛亚历山大藻和中肋骨条藻种群竞争有明显的影响.当塔玛亚历山大藻和中肋骨条藻的接种比例为A∶S = 1∶4时,中肋骨条藻在竞争中占优势; 当接种例为A∶S = 1∶1时,虽然塔玛亚历山大藻在竞争中占优势,但也受到了中肋骨条藻的抑制; 接种比例为A∶S = 4∶1时,塔玛亚历山大藻的生长竞争优势更加明显.UV-B辐射增强(在预备实验的前提下,选择1.4J/m2)可改变塔玛亚历山大藻和中肋骨条藻种群竞争的关系,使塔玛亚历山大藻种群竞争能力降低,中肋骨条藻种群竞争能力大大提高,从而导致处理Ⅰ(A∶S = 1∶4)中,中肋骨条藻在竞争优势更加明显,在处理Ⅱ(A∶S = 1∶1)中,中肋骨条藻在竞争中占一定的优势. 相似文献
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The effect of UV-B radiation enhancement on the interspecific competition between Skeletonema costatum and Heterosigma akashiwo 总被引：4，自引：1，他引：4
1 Introduction R ed tide is a global m arine ecological calam ity.In recentyears, there has been an increase in frequen-cy, affected area and extentof injury of red tide out-breaks in the coastalw aters ofour country.A ccordingto China M arine D isaster B ulletin issued by the StateO ceanic A dm inistration of C hina, harm ful red tideshad occurred up to 119 tim es in 2003, w hich w as 40tim es m ore than thatin 2002. O w ing to the w orsenedcultural environm ent and increased nutrient en… 相似文献