SO2对蚕豆根尖和叶尖细胞遗传损伤作用的研究

采用微核实验技术,研究大气污染物SO₂对蚕豆根尖和叶尖细胞的遗传损伤效应。结果表明2.80和28 mg·m^-3的SO₂熏气可以诱发蚕豆根尖和叶尖细胞损伤,导致根尖细胞有丝分裂指数下降,根尖和叶尖间期细胞微核率增高,并具有时间效应和浓度效应。经水恢复培养后,根尖分裂细胞数增多,微核率降低,说明恢复培养能够缓解高浓度SO₂对根尖细胞的遗传损伤。用石蜡层隔断SO₂在根部水中的溶解后,根尖细胞微核率低于叶尖细胞微核率,而在非隔断组中则相反,说明SO₂在水中的溶解是产生毒性效应的重要原因。高浓度SO₂熏气对蚕豆根尖和叶尖细胞具有遗传学毒性,由于根尖分生区具有较高的分裂指数和微核率,对环境SO₂毒性的反应更灵敏,蚕豆根尖微核实验更适于对环境SO₂的监测。     

蚕豆微核技术监测有机废水的遗传毒性

利用蚕豆根尖细胞微核技术研究有机废水对蚕豆根尖细胞的遗传损伤效应。结果表明:不同稀释梯度的实验室废水对蚕豆根尖细胞的有丝分裂指数、微核千分率及污染指数影响不同,并存在一定的差异。     

SO2对大蒜根尖细胞遗传损伤作用的研究

研究SO2（14,35,84mg/m^2）对大蒜幼根细胞的遗传损伤效应。结果表明：大蒜幼苗短时间暴露于高浓度SO2环境中,或者长时间生长在低浓度SO2环境中,均可导致根尖细胞微核和双核频率明显增高,并引起根尖部分细胞核固缩。SO2的上述效应具有明显的时间－效应和课题－效应关系,细胞中的微核、双核及核固缩率与SO2浓度间呈线性相关,研究结果表明：SO2可引起植物细胞遗传物质的损伤,大蒜根尖细胞有可能用作监测SO2污染的生物计量计。     

化学工业废水对洋葱根类细胞核结构的影响

报道了兰州化学工业公司工业废水对洋葱根尖细胞有丝分裂影响的研究结果．研究表明：（１）兰化工业废水对洋葱根尖细胞分裂具有严重的抑制和危害,其主要表现为间期核结构异常,形成大量的核裂团（Ｎｕｃｌｅｉ－ＳｐｌｉｔＢａｌｌ）和微核（Ｍｉｃｒｏｎｕｃｌｅｉ）;（２）洋葱根尖细胞分裂对环境诱变剂,特别是工业废水的反应是十分敏感的,可以作为环境监测的指示植物。     

褐藻寡糖抗环磷酰胺诱导蚕豆根尖的细胞遗传毒性

采用蚕豆根尖细胞的微核试验和染色体畸变试验方法,测定不同浓度的褐藻寡糖对环磷酰胺(cyclophosphamide,CP)诱导的蚕豆根尖细胞的微核率、有丝分裂指数和染色体畸变率的影响。结果表明:褐藻寡糖能有效抑制环磷酰胺诱导的蚕豆根尖细胞微核的产生,即在一定浓度范围内,微核率随褐藻寡糖处理浓度的降低而减少,但低于一定浓度后反而呈上升趋势;不同浓度的褐藻寡糖均可使蚕豆根尖细胞有丝分裂指数增大;褐藻寡糖还能有效降低蚕豆根尖细胞染色体畸变率。因此,褐藻寡糖对蚕豆根尖细胞具有明显的诱抗活性和调节细胞分裂生长的效应。     

SO2对蚕豆根尖和叶尖细胞遗传损伤作用的研究

采用微核实验技术,研究大气污染物SO2对蚕豆根尖和叶尖细胞的遗传损伤效应。结果表明2.80和28 mg.m-3的SO2熏气可以诱发蚕豆根尖和叶尖细胞损伤,导致根尖细胞有丝分裂指数下降,根尖和叶尖间期细胞微核率增高,并具有时间效应和浓度效应。经水恢复培养后,根尖分裂细胞数增多,微核率降低,说明恢复培养能够缓解高浓度SO2对根尖细胞的遗传损伤。用石蜡层隔断SO2在根部水中的溶解后,根尖细胞微核率低于叶尖细胞微核率,而在非隔断组中则相反,说明SO2在水中的溶解是产生毒性效应的重要原因。高浓度SO2熏气对蚕豆根尖和叶尖细胞具有遗传学毒性,由于根尖分生区具有较高的分裂指数和微核率,对环境SO2毒性的反应更灵敏,蚕豆根尖微核实验更适于对环境SO2的监测。     

紫茎泽兰叶片水浸液对蚕豆的化感效应

外来入侵植物可以通过淋溶、自然挥发、根系分泌和植株凋落物分解等途径向周围环境释放化感物质,抑制伴生植物的生长、发育。该研究以不同浓度紫茎泽兰(Eupatorium adenophorum)叶片水浸液处理蚕豆(Vicia faba)种子,研究紫茎泽兰叶片水浸液对蚕豆根尖细胞微核、染色体畸变、细胞凋亡、蚕豆幼苗叶片叶绿素和N含量、光合生理特性、生物量的影响。结果表明:(1)紫茎泽兰叶片水浸液处理显著抑制蚕豆根尖的伸长和细胞的有丝分裂,并诱导蚕豆根尖细胞染色体畸变和细胞微核的产生,有丝分裂指数随着叶片水浸液浓度增加而减小,根尖细胞微核率随叶片水浸液浓度增加而增大,高浓度叶片水浸液处理对蚕豆根尖细胞的凋亡及坏死有明显影响。(2)紫茎泽兰叶片水浸液处理引起蚕豆幼苗叶片的叶绿素和N含量显著降低,并导致蚕豆幼苗最大净光合速率和生物量的显著下降。总之,紫茎泽兰叶片水浸液可能引起蚕豆根尖的氧化损伤和抑制根尖的伸长,且叶片水浸液的抑制作用呈现一定的剂量效应。紫茎泽兰叶片水浸液对蚕豆根尖的损伤和抑制作用可能影响了植株对氮素的吸收,进而对蚕豆幼苗光合生理表现以及生物量积累产生显著负面效应。     

SO2对蚕豆根尖细胞微核的诱导作用

应用蚕豆根尖微核试验,对SO2的遗传毒性效应进行了研究。结果表明：一定浓度范围内（0.108-14.00mg/m^3）,蚕豆根尖微核细胞数与SO2浓度间呈正相关,太原市大气污染严重的冬季采暖期根尖细胞微核率明显高于非采暖期;SO2浓度0.604mg/m^3处理24h和48h或2.80-28.00mg/m^3熏气处理4h可使蚕豆根尖中具有微核的细胞数明显增加,结果表明,低浓度SO2较长时间接触或高浓度短期接触均可引起蚕豆根尖细胞遗传物质的损伤,应用蚕豆根尖细胞微核实验可对大气SO2污染进行生物监测。SO2（2.80-28.00mg/m^3）熏气实验中,接触时间延长能导致根尖细胞微核率下降,2.80mg/m^3熏气组下降较快,14.00mg/m^3熏气组下降较慢,研究结果提示,在运用蚕豆根尖微核实验监测环境SO2污染时要考虑蚕豆的染毒方式,避免假阴性结果的出现。     

硫酸铜对蚕豆根尖细胞有丝分裂的影响

以蚕豆根尖为材料,研究硫酸铜对蚕豆根尖细胞的遗传毒性效应。采用蚕豆根尖细胞的微核试验方法和染色体畸变试验方法,以不同浓度的硫酸铜为诱变剂,测定蚕豆根尖细胞的有丝分裂指数、微核率和染色体畸变率。结果表明:不同浓度的硫酸铜均能使蚕豆根尖细胞有丝分裂指数明显增加,即5个实验组的分裂指数均明显高于对照组(P<0.01或P<0.001);不同浓度的硫酸铜对蚕豆根尖细胞有丝分裂各期百分数的影响有异;能诱发较高频率的微核率,即在一定浓度范围内,其微核率随硫酸铜处理浓度的升高而增加,但随着硫酸铜浓度的进一步升高而呈下降趋势;硫酸铜还能诱导染色体产生多种类型的畸变,染色体畸变率随硫酸铜处理浓度的升高而增加,随着硫酸铜浓度的进一步升高而呈下降趋势,但均明显高于对照组(P<0.001)。结论是硫酸铜对蚕豆根尖细胞具有明显的遗传毒性效应。     

重铬酸钾对蚕豆根尖细胞致畸效应的研究

以蚕豆根尖为材料,研究重铬酸钾对蚕豆根尖细胞的致畸效应。采用蚕豆根尖细胞的微核试验和染色体畸变试验方法,以不同浓度的重铬酸钾为诱变剂,测定蚕豆根尖细胞的微核率和染色体畸变率。结果表明:重铬酸钾能诱发较高频率的微核率,即在一定浓度范围内,其微核率随重铬酸钾处理浓度的升高而增加,但高于一定浓度后反而呈下降趋势;不同浓度的重铬酸钾均使蚕豆根尖细胞有丝分裂指数增大;重铬酸钾还能诱导蚕豆根尖细胞产生较高频率的染色体畸变,且产生多种类型的染色体畸变。结论是重铬酸钾对蚕豆根尖细胞具有明显的致畸效应。     

青藏高原东缘西藏沙棘(Hippophae tibetana)果实性状变异

西藏沙棘是沙棘属(Hippophae L.)中分布于青藏高原和喜马拉雅高海拔地区的特有类群之一,其果实大小、形状、颜色以及条纹长等性状表现出了高度的多样性。对分布于青藏高原东缘西藏沙棘7个天然居群的果长、果宽、果形系数(果长/果宽)、果柄长、纹长等果实性状变异进行了统计分析,探讨了其果实变异水平及地理变异式样。结果表明,西藏沙棘5个果实性状在居群间和居群内均存在着极显著差异(p0.01)(除纹长在居群间存在着显著差异(p0.05)),居群间变异系数(CV)在11.19%~45.03%之间,果柄长的变异幅度最大(CV为45.03%),其次为纹长(CV为31.97%),变异幅度最小的是果宽(CV为11.19%);表型分化系数(Vst)在0.213 3~0.629 9之间,平均值为0.489 5,居群间和居群内变异约各占果实变异的一半。相关性分析显示,除果长与果柄、果宽与纹长外,其它各性状间均表现出极显著相关(p0.01),除果长与海拔、果宽与经纬度外,其它各性状与地理因子之间均达到极显著相关(p0.01),呈现出地理梯度变异,聚类分析表明7个居群按照地理距离远近聚类。     

Role of the brain in adaptation of the common and golden carps to adverse factors of chemical origin

Using an indirect solid-phase immunoassay (ELISA test), cytochrome P-450, serotoninmodulated anticonsolidation protein (SMAP) and 70-kDa heat shock protein (HSP70) levels were analyzed in the brain and liver of the common carp Cyprinus carpio L. and golden carp Carassius auratus caught in reservoirs of the Arpachay river (clean zone) and Araks river (polluted zone) in Nakhchivan Autonomous Republic of Azerbaijan. Upregulation of cytochrome P-450 (p < 0.05) and SMAP (p < 0.01) in the common carp brain and downregulation of cytochrome P-450 (p < 0.05) and HSP70 (p < 0.05) in the golden carp liver were detected in fish caught in the Araks river reservoir as compared to levels of the same substances in fish from the Arpachay river reservoir. It is concluded that the brain plays a regulatory role in adaptation of animals to adverse environmental conditions and in protection of tissues from negative effects of pollutants.     

喀斯特土壤上香樟幼苗接种不同AM真菌后的耐旱性效应

为探索喀斯特土壤适生植物香樟幼苗在接种不同AM真菌后的耐旱适应性,进行了香樟幼苗接种幼套球囊霉(Glomus etunicatum)和层状球囊霉(Glomus lamellosum)后水分胁迫处理试验。结果表明：（1）接种AM真菌显著提高了香樟幼苗的生物量积累,AM促进植株生物量效应依次为中度>轻度>正常>重度,同一水分胁迫处理下生物量幼套球囊霉>层状球囊霉。（2）中度干旱下香樟幼苗菌根依赖性最大,幼套球囊霉接种植株的菌根依赖性较层状球囊霉大。（3）接种AM真菌显著提高了植株叶片可溶性糖、可溶性蛋白质和脯氨酸含量,并降低了丙二醛含量;在正常供水下植株叶片可溶性糖、可溶性蛋白质和脯氨酸含量层状球囊霉接种>幼套球囊霉接种>对照,干旱胁迫下表现为幼套球囊霉接种>层状球囊霉接种>对照;干旱胁迫下的幼套球囊霉接种植株丙二醛含量低于层状球囊霉接种植株。（4）总体上,可溶性糖与脯氨酸相关性极显著,可溶性蛋白质与丙二醛之间呈显著负相关性。幼套球囊霉接种香樟幼苗的耐旱性高于和层状球囊霉接种香樟幼苗。     

Proliferation of Ciprofloxacin Resistant Bacteria in Polluted Sediments of Musi River,India

Improper disposal of domestic sewage and effluents from drug manufacturing units for several years has resulted in the accumulation of pollutants in Musi river sediments. There were no studies carried out before to quantify the antibiotic resistance in this river, despite the fact that its sediments are loaded with antibiotics. The present study investigated the relationship between the proliferation of ciprofloxacin resistant culture with the occurrence of fluoroquinolone and heavy metals in sediments of Musi River. The fluoroquinolones concentration in river sediments were observed in high concentration (13336.4 ng/g) and were found to be positively correlated with the occurrence of ciprofloxacin resistant bacteria (r = 0.386 to 0.675, p < 0.05). The occurrence of heavy metals was also in positive correlation with the distribution of antibiotic resistant bacteria in the river (r = 0.454 to 0.881, p < 0.05). This study indicated the spread of antibiotic resistance in polluted river sediments that might pose a serious threat to public health as the river water is used for irrigation, drinking, and recreational purposes; and needs an immediate risk assessment and mitigation strategies.     

酸枣叶对土壤水分的生理生化响应

酸枣(Ziziphus jujuba var.spinosa)分布广、适应性强、极耐旱,是研究植物响应干旱气候的优良试验材料。通过覆膜技术控制酸枣根系附近土壤水分含量,研究了不同土壤水分条件对酸枣叶片组织含水量、叶绿素含量、丙二醛、可溶性糖含量等生理生化指标的影响,以期探明酸枣适应干旱的生理机制。结果显示：随着土壤含水量的降低,处理组酸枣叶片的相对含水量与绝对含水量均降低,但都保持在较高水平,与对照相比,差异显著（p<0.05）;自然饱和亏呈下降趋势且维持在较低水平,较对照差异均显著（p<0.05）;随着土壤水分的减少,处理组酸枣叶片较对照组组织水势和渗透势减小（p<0.05）,较对照差异显著（p<0.05）,吸水能力提高;处理组酸枣叶片的叶绿体色素含量随土壤干旱程度的加深,均表现为低于对照且逐渐减少（p<0.05）;随着处理时间的延长,处理组与对照组相比,电导率随之增大,MDA含量也随之升高,质膜受到损伤;处理组酸枣叶片中渗透调节物质可溶性糖含量和游离脯氨酸含量均有不同程度的增加,平均增幅为1.29、1.5倍。结果表明,酸枣叶片在不同的土壤水分条件下,具有积极的生理响应方式,适应性强,具有较强的抗旱耐旱能力。     

Hydroclimatic drivers of the growth of riparian cottonwoods at the prairie margin: River flows,river regulation and the Pacific Decadal Oscillation

Cottonwoods, riparian poplars, are facultative phreatophytes and can obtain water from shallow soil moisture originating from rainfall, or from the deeper capillary fringe above the alluvial water table that is recharged by river water infiltration. The correspondence between cottonwood growth and river flows should reveal the dependency upon alluvial groundwater and subsequently, the vulnerability to reduced river flows. To explore this association, we analyzed historic growth patterns of plains cottonwoods (Populus deltoides) along the Red Deer River (RDR), which is at the northwestern limit of the North American Great Plains. We developed chronologies of yearly radial increments (RI) and basal area increments (BAI) and explored correspondences with the environmental records from the past century. In this semi-arid region, the RI or BAI were not correlated with local precipitation while negative correlation with growth season temperature (T) (r = −0.37, p < 0.01) could reflect reduced growth with hot summers. There was correlation between growth and annual river discharge (Q, and particularly log Q that approximates river stage) and this increased with two year averaging (r = 0.51, p < 0.01), reflecting carry-over in the watershed hydrology and in the ecophysiological response. There was correspondence with the Pacific Decadal Oscillation index (PDO, r = −0.45, p < 0.01), which provides multi-decade transitions that influence Rocky Mountain headwater precipitation and other weather characteristics, and river flows. The combination of Q, PDO and T provided the strongest multiple regression model, accounting for 44% of the historic growth variation (52% correspondence for 1953–2013). The RDR was dammed in 1983, enabling winter flow augmentation, but summer flows were sustained and cottonwood growth and the streamflow correspondence persisted. This indicates that it is the pattern of dam operation and not damming per se that determines the fate of established riparian cottonwoods downstream. This study revealed that these cottonwoods are phreatophytic and dependent upon alluvial groundwater that is recharged from the river. This provides a research strategy to determine whether riparian woodlands along other regulated rivers are similarly groundwater-dependent and could be vulnerable to river flow reductions from excessive water withdrawal for irrigation or other uses, or with climate change.     

不同光照强度下花魔芋（Amorphophallus konjac）与谢君魔芋（Amorphophallus xiei）光合特性及光保护机制研究

为探讨不同耐光性植物光合特性及光保护机制,本研究以耐高光的喜阴植物花魔芋（Amorphophallus konjac K.Coch）和典型的喜阴植物谢君魔芋（Amorphophallus xiei H.Li & Z.L.Dao）为材料,测定与分析在透光率为100%、15%及2%光照条件下两种魔芋的光合能力、抗氧化酶活性及抗氧化物和光合色素组分的含量。结果表明,花魔芋最大光合速率和气孔导度随着生长环境光照强度降低而显著降低（P<0.05）,谢君魔芋在透光率为15%时最大光合速率达最大值。大部分情况下,花魔芋的超氧化物歧化酶、抗坏血酸过氧化物酶、过氧化氢酶、谷胱甘肽还原酶活性比谢君魔芋高（P<0.05）,而谢君魔芋具有较高的过氧化物酶活性（P<0.05）。总的来看,在中高光照环境下两种植物的抗氧化酶活性较高（P<0.05）。在透光率15%时,花魔芋谷胱甘肽和抗坏血酸显著比谢君魔芋高（P<0.05）。谢君魔芋的光合色素含量在透光率为15%时最高（P<0.05）;相应地,花魔芋的光合色素含量在透光率为2%时含量最低（P<0.05）;在不同光照强度下花魔芋光合色素含量基本上显著高于谢君魔芋（P<0.01）。本研究结果暗示,喜阴植物花魔芋耐受高光可能源于相对较高的光合作用能力和有效的光保护机制。     

3种野生地被植物对践踏胁迫的生理生态响应特征

不同强度践踏胁迫下,对3种野生地被植物主要生理生态响应特征进行了研究,结果表明：重度践踏胁迫下匍枝委陵菜的盖度、生物量下降幅度最大,和对照相比分别下降46.58%和43.53%。重度践踏胁迫下车前的纤维素含量最高,比对照增加43.31%。中度践踏胁迫下紫花地丁丙二醛含量积累最少,比对照升高28.57%。紫花地丁叶绿素含量对践踏胁迫响应敏感,轻度践踏可使叶绿素含量提高45.21%（p< 0.05）,重度践踏使匍枝委陵菜和紫花地丁的叶绿素含量分别下降了21.59%和29.37%。践踏胁迫使3种野生地被植物的群体净光合速率下降。综合分析结果为车前最耐践踏,紫花地丁次之,匍枝委陵菜最不耐践踏。     

An intertidal limpet species as a bioindicator: Pollution effects reflected by shell characteristics

Mollusc shells have been widely used for monitoring the bioavailability of contaminants in the aquatic environment. The present work examined malformations among the shells of the limpet Siphonaria lessoni from heavily polluted, light polluted and unpolluted sites in Argentina. Data on shell shape, thickness, dry weight, microstructure and semi-quantitative elemental composition was evaluated as well as soft tissue dry weight. Shells from the heavily polluted site were significantly (p < 0.001) thicker than those from other areas. SEM (scanning electron microscopy) analysis of thickened shells revealed the presence of globular malformations on inner shell surfaces. On heavily polluted shells, elemental composition analysis by EDS (electron dispersive spectroscopy) of such malformations indicated concentrations three times higher of carbon and four times lower of calcium and oxygen than the control. Light polluted shells presented concentrations two times lower of calcium. In addition, soft tissues were lighter at the heavily polluted site (p < 0.001). These data demonstrate the sensitivity of this abundant and widely distributed intertidal limpet to aquatic pollutants, and support the use of this limpet as a potential biomarker.     

三种水生植物对苯的净化作用及条件优化

为了探讨水生植物对含苯污染水体的修复效果,采用L₂₇(3¹³)正交设计法,研究了3种水生植物普生轮藻（Chara vulgaris L.）、豆瓣菜（Nasturtium officinale R.Br.）和菹草（Potamogeton crispus L.）对水体中苯的净化作用。结果表明,在实验条件下,3种植物对苯的最大去除率分别达到35.26%、69.71%和55.45%。温度、作用时间、生物量及温度与时间、温度与生物量的交互作用对普生轮藻去除苯的作用影响显著。温度和生物量对豆瓣菜去除苯的作用影响显著。作用时间对菹草去除苯的作用影响显著。3种植物均可作为良好的水质净化材料。普生轮藻和豆瓣菜适合在夏秋季选用,而菹草则适合冬春季选用。