沉水植物菹草对富营养化水体中TN 生态效应及模型研究

通过室内模拟构建水体营养盐和菹草生物量正交试验, 研究菹草从石芽萌发至菹草植株衰亡腐烂整个生命周期中, 对水体中TN 的生态效应, 并以此为依据建立菹草对富营养化水体生态效应模型。研究表明: 在不同生物量菹草作用下, 富营养化水体中TN 含量是先下降后上升的一个周期式过程; 在相同营养水平条件下, 菹草对TN 的吸收量随菹草生物量的增大而依次递增, 而在相同生物量的前提下, 菹草对TN 的修复力存在一个最佳营养水平范围, 即13.95-20.56 mg·L–1 之间; 菹草对富营养化水体生态效应模型分两部分: 菹草对富营养化水体中TN 与时间关系模型以及菹草生态修复水体TN 限度理论模型, 通过这两个模型的构建可以为生产实践中菹草在生态修复富营养化水体的投放量和菹草的最佳收割时间提供有力依据, 为工程实践提供有效保障。     

富营养化河道引清渐推生态修复工程模式研究

2014 年2 月10 日至3 月28 日对滴水湖外围中涟河道实施以引清调水引导的沉水植物生态修复工程, 从临近的D 港引入清水快速提高水体透明度, 然后移栽苦草(Vallisnerianatans)、伊乐藻(Elodea nuttalii)、龙须眼子菜(Potamogetonpectinatus)等沉水植物, 构建水生植物群落。跟踪监测总氮(TN)、氨态氮(NH4⁺-N)、硝态氮(NO3^–-N)、亚硝态氮(NO₂^–-N)、总磷(TP)和磷酸盐(PO₄^3–-P)等水质指标, 分析该生态工程对富营养化河道的修复效果。结果表明: 工程实施后第2 个月, 修复区沉水植物的覆盖率由移栽初期的60%提高到85%, 水体综合营养状态指数比对照区降低了19.31%, 达到中营养水平, 修复效果显著(P<0.05)。6 个月后, 修复河道水体内总氮、氨态氮、硝态氮、亚硝态氮、总磷、磷酸盐的浓度与对照区相比显著降低, 削减率分别为43.86%、61.17 %、51.90 %、72.62 %、43.86 %和55.71%, 水体透明度比对照区提高81.82%, 综合营养状态指数显示修复区水体仍保持在中营养状态。引清渐推生态修复工程对富营养化河道修复效果明显, 为我国南方河网较密集区的河道生态修复提供更多的治理思路。     

真江蓠(Gracilaria verrucosa)对网箱养殖海区的生态修复及生态养殖匹配模式

2006年8～9月,在浙江象山港花鲈(Lateolabrax japonicus)养殖网箱中吊养真江蓠(Gracilaria verrucosa)对网箱养殖造成的水体富营养化进行生态修复研究.通过45d内的平面监测、定点跟踪监测和断面监测,结果表明:该网箱养殖区水体呈严重富营养化状态,营养状态指数(E)为32.00,其营养盐分布由高浓度的中心区向周围150m非养殖水域扩散;真江蓠对养殖区的富营养化海水具有较好的修复效果:江蓠生态修复区及其相邻网箱中水体PO4-P、NO2-N、NH4-N和NO3-N含量显著低于非修复区(P＜0.01),修复区海水PO4-P、NO2-N、NH4-N和NO3-N浓度比非修复区分别降低22%～58%、24%～48%、22%～61%和24%～47%.养殖真江蓠45d后,修复区水体DO浓度和透明度显著高于非修复区(P＜0.05),DO平均提高28%,透明度平均提高30%;而修复区水体Chl-a浓度显著低于非修复区(P＜0.05),平均降低49%.通过建立基于N平衡的鱼藻生态养殖模式,每收获1kg花鲈至少需要匹配江蓠4.7 kg wet wt才可实现对鱼类排放N的完全吸收.因此网箱内栽培江蓠的混合生态养殖模式,可平衡因经济动物养殖所带来的额外营养负荷,有利于实现动物养殖环境的自我修复.     

常见湿生植物对镉、铅污染水环境的修复效果研究

采用水培法,采用不同浓度镉(Cd)和铅(Pb)的4种处理对6种常见湿生植物:豆瓣菜(Nasturtium of?ficinale R. Br.)、水萝卜(Raphanus sativus L.)、沼生蔊菜(Rorippa islandica(Oed.)Borb.)、白芥(Sinapis alba L.)、水芹(Oenanthe javanica(Blume)DC.)和蕹菜(Ipomoea aquatica Forsk.)幼苗的生长、重金属积累与转运、抗氧化酶活性及根细胞死亡的影响进行研究。结果显示,在Cd、Pb单一及复合胁迫下,豆瓣菜、水芹的根长、根重、植株干重均显著低于对照;而经单一Pb处理的水萝卜、白芥的根长、植株干重高于对照。单一Cd处理组中,6种植物富集系数大小依次为:豆瓣菜沼生蔊菜水芹水萝卜蕹菜白芥。Pb单一胁迫后,豆瓣菜对Pb的富集系数最小,仅为0013。水萝卜幼苗在Cd和Pb复合胁迫下生长状况与对照相比无显著差异,且Cd、Pb转运系数增大,抗氧化酶活性较高,根细胞死亡较少,表明该物种是具有较好修复潜力的植物。     

穗花狐尾藻(Myriophyllum spicatum L.)在不同程度富营养化水体中的营养积累特点及营养分配对策

通过对栽培于3个不同程度的富营养化水体(富营养化程度为水体1<水体2<水体3)中的穗花狐尾藻(MyriophyllumspicatumL.)进行研究,测定了不同时期植物体各个器官的氮磷含量及生物量分配,探讨了富营养化水对其营养积累及分配格局的影响。结果表明,重度富营养化的水体3中穗花狐尾藻组织中的氮含量显著高于其它两个水体;而由于水体1和水体2的氨态氮含量无显著差异,植物组织中的氮含量在水体1和水体2间无显著差异。富营养化程度高的水体2中植物磷的含量显著低于富营养化程度低的水体1中的植物,但在重度富营养化的水体3中,叶子的磷含量却远高于其它两个水体,这是由植物不同部位吸收的磷在各器官间分配不同所造成的。由于底泥的营养含量丰富,在3个不同程度的富营养化水体中,穗花狐尾藻的根冠比并未表现出明显差异。     

NH_4~+-N、TN、TP和DO对泥鳅的氧化损伤作用研究

目的:水体富营养化给渔业的发展造成严重的负面影响,成为全球瞩目的环境问题之一。方法:本研究利用泥鳅(Misgurnus anguillicaudatus)作为实验生物,选择氨氮(NH4+-N)、总氮(TN)、总磷(TP)和溶解氧(DO)含量作为富营养化水体的影响因素。研究富营养化水体中NH4+-N、TN、TP和DO含量对泥鳅抗氧化酶活性和脂质过氧化水平的影响,旨在阐明富营养化水体对鱼类的氧化损伤作用。结果:随着水体中NH4+-N、TN、TP和DO含量的增加,泥鳅的SOD活性显著降低(P0.05),MDA含量显著增加(P0.05)。与正常的DO水平相比,水中高浓度和低浓度的氧含量都会造成SOD活性的显著下降(P0.05)和MDA含量的显著上升(P0.05)。其中NH4+-N和DO的影响最大。结论:富营养化水体对鱼类的危害与其造成的鱼类氧化损伤有直接关系,实验的开展为富营养化水体的生物监测与评价具有一定指导作用。     

穗花狐尾藻(Myriophyllum spicatum L.)在不同程度富营养化水体中的营养积累特点及营养分配对策

通过对栽培于3个不同程度的富营养化水体(富营养化程度为水体1<水体2<水体3)中的穗花狐尾藻(MyriophyllumspicatumL.)进行研究,测定了不同时期植物体各个器官的氮磷含量及生物量分配,探讨了富营养化水对其营养积累及分配格局的影响。结果表明,重度富营养化的水体3中穗花狐尾藻组织中的氮含量显著高于其它两个水体;而由于水体1和水体2的氨态氮含量无显著差异,植物组织中的氮含量在水体1和水体2间无显著差异。富营养化程度高的水体2中植物磷的含量显著低于富营养化程度低的水体1中的植物,但在重度富营养化的水体3中,叶子的磷含量却远高于其它两个水体,这是由植物不同部位吸收的磷在各器官间分配不同所造成的。由于底泥的营养含量丰富,在3个不同程度的富营养化水体中,穗花狐尾藻的根冠比并未表现出明显差异。     

潜水式生态介质箱对黑臭水体的修复效果

生态浮床作为一种常规治理技术得到了广泛使用,但其只能修复表层富氧水体,对下层缺氧水体的修复能力有限.本研究针对实际黑臭水体的修复需要,设计了潜水式生态介质箱(潜水组),并以传统的生态浮床(浮床组)为对照进行对比试验,研究修复前后黑臭水体的水质变化,考察了水生植物的生长状况及N、P积累能力.结果表明:随着修复时间的延长,两组处理对各污染物的去除率均逐渐升高,其中潜水组去除全氮(TN)、铵氮(NH4^+-N)、全磷(TP)的能力优于浮床组,但其去除化学需氧量(CODMn)的能力稍逊;潜水组植物(苦草)的生长状况优于浮床组植物(菖蒲),且苦草对水体中TN、TP的吸收积累能力和去除贡献率均优于菖蒲;此外,苦草的质膜透性、丙二醛和叶绿素含量均低于菖蒲,说明苦草更适于在黑臭水体中生长,该潜水式生态介质箱是新型的一体化原位修复装置,更适用于黑臭水体的修复实践.     

太湖五里湖生态修复示范区水质改善效果分析

鱼类清除和沉水植被恢复常是富营养化浅水湖泊生态系统修复的重要手段。为探讨这种生态系统修复方式对亚热带富营养化浅水湖泊太湖五里湖水质的改善效果,论文研究了五里湖生态修复区与未进行任何修复的对照湖区为期6个月(2010年7～12月)的水质监测数据。数据分析结果表明,生态修复区总氮(TN)、总磷(TP)、叶绿素-a(Chl-a)以及悬浮质(TSS)浓度显著降低,分别比对照区低43.4%、48.3%、65.5%和78.9%,透明度则明显升高,约为对照区的3倍。本研究表明以鱼类清除和沉水植被恢复为主要手段的生态系统修复措施能够有效改善亚热带富营养化浅水湖泊水体的水质。     

不同水体营养状态对（韰）和（鱼康 鱼良）白鱼生长性能的影响

和白鱼分别是抚仙湖的外来鱼类和土著鱼类.本实验比较研究了水体营养状态对二者生长性能的影响.实验鱼养殖在低、中、高三种营养状态的水体中.其中低营养状态水体组又是每一种鱼中、高营养水体组的对照.水体营养状态对韰和鏮鋃白鱼摄食率、生长速度、饵料转化效率、蛋白贮积率没有显著影响.不同营养状态水体组实验鱼的体蛋白、脂肪、灰分和能量含量没有显著差异.富营养化对两种鱼生长性能的影响是不同的.特定生长率、饵料转化效率、蛋白贮积率和能量贮积率的种间差异值均随着水体营养状态的提高而加大.与对照组相比,较高营养状态水体中的摄食率、特定生长率、饵料转化效率、蛋白贮积率和能量贮积率的增加率低于鏮鋃白鱼,或者降低率高于鏮鋃白鱼.实验结果说明,高营养状态对生长性能的负面影响较大;对于湖泊水体的富营养化,外来鱼类在生长性能方面不一定比土著鱼类具有优势.     

海岸桐的抗旱生物学特性

南沙群岛土壤主要以珊瑚砂为主,由于其光照强、土壤水分和养分贫瘠等环境条件,导致很少植物能够在岛上正常生长.为了快速恢复南沙岛礁的植被,需要筛选出抗旱性强的植物并进行引种.海岸桐(Guettarda speciosa)是一种典型的热带海岸植物,在海岛和海岸带防风固沙及植被生态恢复等方面发挥着重要作用.该文以西沙永兴岛自然...     

遮荫处理对秋枫幼苗生理生态特性的影响

为了解遮荫对秋枫(Bischofia javanica)幼苗生长的影响,对夏季1年生秋枫幼苗在4种遮荫(透光率分别为自然光的100%、41.3%、14.6%和3.6%)处理150 d后的生理指标变化进行了研究。结果表明,1年生秋枫幼苗的光补偿点(LCP)、光饱和点(LSP)和暗呼吸速率(Rd)随着遮荫程度加重而减小,表观量子效率(AQY)则增大,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和胞间CO_2浓度(Ci)的日变化表明秋枫有明显的"午休"现象,遮荫引起光合速率降低的主要原因是非气孔限制,而全光照条件下则是气孔限制。叶绿素、可溶性糖含量随遮荫程度的增大呈先升后降的变化趋势;相对电导率、丙二醛(MDA)含量、过氧化氢酶(CAT)活性则呈先降后升的趋势,以41.3%透光率的最小;可溶性蛋白质含量、超氧化物歧化酶(SOD)活性随遮荫程度的增大而降低。因此,秋枫幼苗主要通过提高Pn、抗氧化酶活性(SOD和CAT)、叶绿素含量,降低LSP、LCP和Rd,增大AQY来提高弱光利用能力;适度遮荫(41.3%NS)更有利于1年生秋枫幼苗在夏季的生长。     

Adjustment of parental expenditure in sympatric <Emphasis Type="Italic">Onthophagus</Emphasis> beetles (Coleoptera: Scarabaeidae)

Many organisms adjust their parental expenditure to offspring in response to resource quality. However, the mechanisms underlying the adjustment in parental expenditure are not well understood. We examined the adjustments in parental expenditure and subsequent offspring performance in two sympatric, closely related dung beetles, Onthophagus ater and O. fodiens, that were provided either monkey, deer, horse, or cow dung. The egg contained within each dung brood mass provisioned by the parent beetles develops to adulthood underground. Thus, the size of the brood mass roughly represents the amount of parental expenditure. The brood mass size differed between the two species and among the four dung types. Results of offspring performance suggested that O. ater parents optimally adjusted the brood mass size in response to dung quality, whereas O. fodiens parents did not. We hypothesized that brood mass size in O. ater may increase with prolonged egg maturation caused by the lower nutrition level of cow dung. In addition, our complex results may be explained in part by the specific threshold concept of dung quality (i.e., water content and nutritional level).     

热带滨海植物红厚壳的抗逆生物学特性

为了解红厚壳(Calophyllum inophyllum)的抗逆特性,对西沙群岛自然生长的红厚壳叶片的形态解剖、生理生态、以及叶片和适生土壤的元素含量进行了研究。结果表明,红厚壳是阳生性植物,其上表皮厚,海绵组织发达且栅栏组织排列紧密,气孔排列松散且密度小(24.40 mm~(-2)),有利于叶片保水抵御干旱。叶片的叶绿素a、b含量低(分别为0.87和0.43 mg g~(-1)),表明红厚壳具适应强光环境的能力。叶片的MDA含量低(13.46 nmol g~(-1)),PRO含量高(127.89μg g~(-1)),SOD活性高(149.42 U g~(-1)),总抗氧化能力高(388.60 U g~(-1)),显示红厚壳能通过提高自身的抗氧化能力抵御膜脂过氧化伤害。红厚壳自然生长的珊瑚岛土壤较为贫瘠、营养元素含量低,但红厚壳植株体内具有较高的营养元素含量,表明红厚壳营养元素利用率高,对于贫瘠土壤具有很好的适应能力。因此,红厚壳具有较高的抗氧化胁迫能力和耐受干旱的能力,适宜生长在热带珊瑚岛等土壤贫瘠的生境,可以作为热带珊瑚岛防风固沙和植被恢复的工具种。     

滨豇豆的生态生物学特征

为探究滨豇豆(Vignamarina)的生态生物学特性及其对热带珊瑚岛的适应性,对西沙群岛野生滨豇豆的叶片形态解剖结构、生理特征和营养成分进行了分析。结果表明,滨豇豆具有叶片厚、比叶面积小、栅栏组织发达、气孔密度大、气孔面积指数大等形态特征,对减少蒸腾、保持水分起到重要作用。滨豇豆叶片的SOD活性和脯氨酸(Pro)含量高,丙二醛(MDA)含量低,表明抗氧化能力较强;滨豇豆叶片养分含量适中但其生境土壤养分含量很低,说明其对养分有着良好的吸收利用能力,利于适应贫瘠的环境。因此,滨豇豆具有能够较好地适应珊瑚岛礁高温、干旱、贫瘠生境的形态解剖结构和生理特征,加之其具有良好的固氮和养分利用能力,可作为热带珊瑚岛植被恢复的工具种。     

响应面法优化爪哇虫草菌的培养条件及其对斜纹夜蛾的毒力和保护酶活性影响

【目的】优化爪哇虫草菌Bd01的固态发酵培养条件,测定分生孢子对斜纹夜蛾3龄幼虫的毒力,研究被爪哇虫草菌侵染后寄主体内的保护酶活性变化。【方法】采用单因素试验确定爪哇虫草菌Bd01最佳的固态培养基及培养条件,利用Box-Behnken响应面法优化发酵参数,采用浸渍法测定分生孢子对斜纹夜蛾3龄幼虫的毒力,同时利用分光光度计法测定斜纹夜蛾3龄幼虫体内酶活性变化。【结果】以产孢量为指标,通过响应曲面法优化的爪哇虫草菌Bd01最佳产孢条件为：培养基营养成分含量为30.24g/L,pH值为7.55,光照时长为12.06h,在该条件下,培养基的产孢量为2.78×10⁸孢子/mL。浓度为1×10⁸孢子/mL的爪哇虫草菌孢子液对斜纹夜蛾3龄幼虫具有一定毒力,处理7 d时致死中浓度(LT₅₀)为3.11 d,致死中时(LC₅₀)为4.68×10⁵孢子/mL,校正死亡率为88.68%。处理后未死亡的斜纹夜蛾幼虫体内保护酶活性与对照组相比发生显著变化。【结论】优化后的培养基能够显著增加爪哇虫草菌的产...     

Cracks or holes in the stems of oviposition plants provide the only exit for hatched larvae of diving beetles of the genera Dytiscus and Cybister

Diving beetles such as Dytiscus and Cybister species (Coleoptera: Dytiscidae) usually oviposit inside an aquatic plant stem beneath the surface of the water. The hatched larvae need to escape from the stem to intake oxygen from the air. To determine where larvae of these diving beetles hatch in the plant stem, the hatchability and escape rates in larvae of Dytiscus sharpi Wehncke, Cybister chinensis Motshulsky, Cybister lewisianus Sharp, and Cybister brevis Aubé were investigated under laboratory conditions. Hatchability of D. sharpi in the stem of Sagittaria trifolia L. (Alismataceae) was extremely low (8.2%). However, it was high (>90%) when late‐stage eggs (2–3 days before hatching) were isolated from the stem and kept in water. On the other hand, the hatchability of Cybister spp. was high (88–95%) in S. trifolia. Usually, Cybister spp. females bite a hole in the plant stem on oviposition. When the oviposition pore in the stem was plugged with glass wool, no larvae could escape from the stem, indicating that the oviposition pore was the only exit for hatched larvae of Cybister spp. In contrast, females of D. sharpi oviposited directly by making a crack in the stem of Oenanthe javanica (Blume) DC. (Apiaceae) without biting. Eggs grew to a length and diameter equal to the stem crack size 2–3 days before hatching. Dytiscus sharpi eggs isolated from O. javanica were artificially inserted into plant stems of O. javanica or S. trifolia (so‐called inserted egg model), and the hatchability and larval escape rates were determined. Larval escape strongly depended on the stem crack width of both O. javanica and S. trifolia, suggesting that the stem crack was an exit for hatched larvae of D. sharpi.     

Differential responses of lipid peroxidation and antioxidants in <Emphasis Type="Italic">Alternanthera philoxeroides</Emphasis> and <Emphasis Type="Italic">Oryza sativa</Emphasis> subjected to drought stress

To evaluate oxidative stress and the plant antioxidant system of Alternanthera philoxeroides [Mart.] Griseb and Oryza sativa L. in the response to drought, root and leaf tissues of drought-treated A. philoxeroides and O. sativa were collected and relative water content, stomatal conductance, the concentrations of malondialdehyde, proline and the activities of superoxide dismutase, peroxidases, catalase and total antioxidative activity investigated. The results showed that drought treatment had almost no effect on relative water content in A. philoxeroides but reduced relative water content in O. sativa. A. philoxeroides maintained a greater stomatal conductance than O. sativa under drought stress. In A. philoxeroides levels of lipid peroxidation were lower than in O. sativa and did not change during the experiment. After exposure to drought, concentrations of proline and activities of superoxide dismutase, peroxidases and catalase in A. philoxeroides were between 10% and 30% higher than in O. sativa, whereas total antioxidative activity in A. philoxeroides was several-fold higher than in O. sativa.     

Interaction of Glomus mosseae and Paecilomyces lilacinus on Meloidogyne javanica of tomato

The effects of Glomus mosseae and Paecilomyces lilacinus on Meloidogyne javanica of tomato were tested in a greenhouse experiment. Chicken layer manure was used as a carrier substrate for the inoculum of P. lilacinus. The following parameters were used: gall index, average number of galls per root system, plant height, shoot and root weights. Inoculation of tomato plants with G. mosseae did not markedly increase the growth of infected plants with M. javanica. Inoculation of plants with G. mosseae and P. lilacinus together or separately resulted in similar shoots and plant heights. The highest root development was achieved when mycorrhizal plants were inoculated with P. lilacinus to control root-knot nematode. Inoculation of tomato plants with G. mosseae suppressed gall index and the average number of galls per root system by 52% and 66%, respectively, compared with seedlings inoculated with M. javanica alone. Biological control with both G. mosseae and P. lilacinus together or separately in the presence of layer manure completely inhibited root infection with M. javanica. Mycorrhizal colonization was not affected by the layer manure treatment or by root inoculation with P. lilacinus. Addition of layer manure had a beneficial effect on plant growth and reduced M. javanica infection.     

Identification of resistance to Meloidogyne javanica in the Lycopersicon peruvianum complex

Clones of Lycopersicon peruvianum PI 2704352R2, PI 270435-3MH and PI 126443-1MH expressed novel resistance to three Mi-avirulent M. javanica isolates in greenhouse experiments. Clones from PI 126443-1MH were resistant to the three M. javanica isolates at 25°C. The three isolates were able to reproduce on one embryorescue hybrid of PI 126443-1MH, but not on three L. peruvianum-L. esculentum bridge-line hybrids of PI 1264431MH when screened at 25°C (Mi-expressed temperature). Clones of PI 270435-2R2 and all its hybrids with susceptible genotypes were resistant to the three M. javanica isolates at 25°C. The bridge-line hybrid EPP-2xPI 2704352R2 was susceptible to M. javanica isolate 811 at 32°C, whereas PI 270435-2R2 and all other hybrids of PI 27043 5-2R2 crossed with susceptible genotypes were resistant at 32°C. At 32°C, one F₂ progeny of PI 126443-IMHxEPP-1, and three test-cross progenies of PI 1264409MHx[PI 270435-3MHxPI 126443-1MH], and reciprocal test-cross progenies of [PI 270435-3MHxPI 2704352R2]xPI 126440-9MH, each segregated into resistant: susceptible (RS) ratios close to 31. The results from the F₂ progeny indicated that heat-stable resistance to Mi-avirulent M. javanica in PI 126443 -1MH is conferred by a single dominant gene. The results from the test-crosses indicated that this gene in PI 126443-1MH is different from the resistance gene in PI 270435-3MH. The resistance gene in PI 270435-3MH was also shown to differ from the resistance factor in PI 270435-2R2. The expression of differential susceptibility and resistance to M. javanica and M. incognita in individual plants of the bridge-line hybrid, embryo-rescue hybrid, F₂, and test-crosses indicated that at least some genes governing resistance to M. javanica differ from the genes conferring resistance to M. incognita. A new source of heat-stable resistance to M. javanica was identified in Lycopersicon chilense.