不同沉水植物对沉积物磷迁移转化的影响

选择了微齿眼子菜(Potamogeton maackianus A.Benn .)、穗花狐尾藻(Myriophyllum spicatum L .)和金鱼藻(Ceratophyllum demerswn L .)3种沉水植物,在温室模拟研究了不同沉水植物对湖泊沉积物磷迁移转化的影响.研究结果表明,随着培养时间的延续微齿眼子菜和穗花狐尾藻对沉积物NaOH-P有明显的吸收和转化作用,分别吸收和转化了36.9%和33.2%,而金鱼藻对沉积物NaOH-P的影响不显著;各处理随着植物的生长,由于根系的吸收作用,沉积物中Olsell-P发生了从非根际→根际→沉水植物的迁移过程,其中微齿眼子菜和穗花狐尾藻更为明显.因此,微齿眼子菜和穗花狐尾藻对沉积物磷释放的控制作用更为明显.     

外加碳源及沉水植物对沉积物各形态磷的影响

以原沉积物(处理1)和添加0.4%葡萄糖(碳源,处理2)的沉积物作为底质培养狐尾藻,采用室内模拟实验,研究了外加碳源及沉水植物对沉积物有机和无机磷形态的影响。结果表明:随着培养时间的延续,狐尾藻的生长促进了沉积物中磷的释放,其衰退增加了沉积物中磷的沉积;沉水植物对磷的不同赋存形态的影响并不相同,其中对无机磷形态中的Fe/Al-P和有机形态磷中的活性有机磷有显著的影响(p<0.05),而对其它形态磷的影响没有表现出统计差异;无论有无种植沉水植物,外加碳源可促进了沉积物Fe/Al-P和有机磷释放,增加了Ca-P固定;外加碳源显著提高了有机磷中活性有机磷的质量分数(p<0.05),降低了稳定性有机磷的质量分数,而种植沉水植物可显著降低活性有机磷质量分数。说明碳源和沉水植物对沉积物中磷形态分布有重要影响。     

外加碳源及沉水植物对沉积物各形态磷的影响

以原沉积物（处理1）和添加0.4%葡萄糖（碳源,处理2）的沉积物作为底质培养狐尾藻,采用室内模拟实验,研究了外加碳源及沉水植物对沉积物有机和无机磷形态的影响。结果表明：随着培养时间的延续,狐尾藻的生长促进了沉积物中磷的释放,其衰退增加了沉积物中磷的沉积;沉水植物对磷的不同赋存形态的影响并不相同,其中对无机磷形态中的Fe/Al-P和有机形态磷中的活性有机磷有显著的影响（p〈0.05）,而对其它形态磷的影响没有表现出统计差异;无论有无种植沉水植物,外加碳源可促进了沉积物Fe/Al-P和有机磷释放,增加了Ca-P固定;外加碳源显著提高了有机磷中活性有机磷的质量分数（p〈0.05）,降低了稳定性有机磷的质量分数,而种植沉水植物可显著降低活性有机磷质量分数。说明碳源和沉水植物对沉积物中磷形态分布有重要影响。     

不同质量浓度氨氮对轮叶黑藻和穗花狐尾藻抗氧化酶系统的影响

在不同质量浓度(0、0.2、1.5、2.0、4.0、8.0 mg·L-1)氨氮条件下,对沉水植物轮叶黑藻[Hydrilla Verticillata(L.f) Royle]和穗花狐尾藻[Myriophyllum spicatum L.]的蛋白质含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)及过氧化物酶(POD)活性变化进行了研究.实验结果显示,当氨氮质量浓度为0.2 mg·L-1时,为轮叶黑藻的适宜生长质量浓度,表现为常用的膜脂过氧化指标MDA含量和SOD活性均变化比较平缓,且蛋白质含量增加,而穗花狐尾藻由酶学指标显示,氨氮质量浓度小于0.2 mg·L-1时对它的正常生理代谢产生了影响;当氨氮质量浓度在1.5～4.0 mg·L-1的范围则对轮叶黑藻产生胁迫作用,而穗花狐尾藻在此质量浓度范围能正常生长;当氨氮质量浓度为8.0 mg·L-1时,高氨氮对2种沉水植物都表现出胁迫效应,且对轮叶黑藻的胁迫作用更强.实验结果表明在进行湖泊水生植物修复时,相对于轮叶黑藻,穗花狐尾藻更适合作为生态恢复的先锋物种.     

不同生活型植物腐解过程对人工湿地水质的影响研究

为探讨不同生活型水生植物腐解对石佛寺人工湿地水体水质的持续影响,在室内模拟3种生活型(浮叶型、挺水型和沉水型)6种水生植物(槐叶苹Salvinia natans和丘角菱Trapa japonica;蒲草Typha angustifolia和荷花Nelumbo nucifera;穗状狐尾藻Myriophyllum spicatum和金鱼藻Ceratophyllum demersum)的腐解过程,研究植物类型、生物量以及底泥对营养盐释放过程的影响程度。结果表明:(1)浮叶植物和沉水植物最易腐解,而挺水植物腐解最慢,沉水植物腐解最彻底,且生物量越大释放的营养物质越多;(2)同生活型植物之间p H值的变化具有很强的相关性(r0.826,P0.05),且底泥不影响p H的变化趋势,DO变化趋势因生活型不同存在明显差异;(3)挺水植物有机物释放过程较浮叶植物和沉水植物漫长,氮和碳的变化有一定相关性,底泥不影响水中氮的变化趋势,但对水中氮的浓度高低有影响;(4)浮叶植物组和挺水植物组磷的释放速率高于沉水植物,水体中磷浓度的高低与底泥和植物生物量有关,磷在水体和底泥存在明显吸附沉淀和迁移现象。     

不同水深条件下狐尾藻生长对沉积物氮磷的影响

采用巢湖原位试验研究了80、160和240 cm 3个水深条件下生长的沉水植物狐尾藻(Myriophyllum spicatum L.)对沉积物和间隙水中氮磷的影响。结果表明,狐尾藻的株高和生物量随着水深的增加总体呈下降趋势,并且其差异随着生长期的延长而加大,水深为240 cm的条件下狐尾藻具有最小的株高和生物量,即240 cm的大水深条件不利于狐尾藻的个体形态构建;而相对浅的水深条件(80和160 cm)则是其生长的较佳生境。狐尾藻的生长过程中能够通过根系吸收和根际环境的改变使沉积物和间隙水中的氮磷含量明显下降,一定程度上降低了沉积物氮磷向上覆水体释放的风险,并且其抑制能力随着不同水深条件下植株的长势不同而有所差异,即在植株生长良好的浅水条件下其对沉积物和间隙水中氮磷的抑制效果更佳。因此,较浅的水环境有利于沉水植物的生长,同时还能充分发挥植物对沉积物氮磷的控释作用。     

不同水深条件下狐尾藻生长对沉积物氮磷的影响

采用巢湖原位试验研究了80、160和240 cm 3个水深条件下生长的沉水植物狐尾藻（Myriophyllum spicatum L.）对沉积物和间隙水中氮磷的影响。结果表明,狐尾藻的株高和生物量随着水深的增加总体呈下降趋势,并且其差异随着生长期的延长而加大,水深为240 cm的条件下狐尾藻具有最小的株高和生物量,即240 cm的大水深条件不利于狐尾藻的个体形态构建;而相对浅的水深条件（80和160 cm）则是其生长的较佳生境。狐尾藻的生长过程中能够通过根系吸收和根际环境的改变使沉积物和间隙水中的氮磷含量明显下降,一定程度上降低了沉积物氮磷向上覆水体释放的风险,并且其抑制能力随着不同水深条件下植株的长势不同而有所差异,即在植株生长良好的浅水条件下其对沉积物和间隙水中氮磷的抑制效果更佳。因此,较浅的水环境有利于沉水植物的生长,同时还能充分发挥植物对沉积物氮磷的控释作用。     

两种底质对狐尾藻生长和生理指标的影响

在温室条件下,分别以土壤和沉积物作为底质,模拟研究狐尾藻(Myriophyllum spicatum)生长和生理指标的变化。结果表明:与营养水平相当的沉积物相比,以土壤作为底质的处理,其狐尾藻茎叶生物量降低了87.15%,根系生物量增加了226.54%,根系活力降低了46.46%,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性分别增加了134.20%和119.91%,上覆水和间隙水中活性磷浓度分别增加了146.67%和1382.61%。以土壤为底质,增加该处理水体中磷浓度,抑制狐尾藻生长。     

沉水植物对沉积物中磷赋存形态影响的初步研究

采用磷的分级方法研究苦草移植后生长过程中沉积物不同的磷赋存形态(NH4Cl-P, BD-P, NaOH-P和HCl-P)以及总磷的变化,同时结合野外人工恢复的水草区域采样的结果,进一步分析了野外条件下沉水植物狐尾藻(Myriophyllum spicatum L.)对磷赋存形态的影响,结果表明,沉水植物能够有效的降低沉积物中磷的含量,而且水生植物对磷的不同赋存形态的影响并不相同,其中,BD-P是受沉水植物影响最为明显的磷赋存形态.     

水体营养水平对3种沉水植物生长及抗氧化酶活性的影响

模拟研究了沉水植物狐尾藻Myriophyllum spicatum L、轮叶黑藻Hydrilla verticillata L和金鱼藻Ceratophyllum demersum L在中、富两种营养水平下的生长及生理特性.研究结果表明,在45 d的培养过程中,狐尾藻、轮叶黑藻和金鱼藻在中营养(TN1.86 mg·L-1;TP0.087 mg·L-1)和富营养(TN2.47 mg·L-1;TP0.16 mg·L-1)水平下的单株最大生物量分别是0.92、0.27、1.11、0.56、0.41和0.87 g,狐尾藻和金鱼藻在中营养水平下单株最大生物量分别较富营养水平下高出39%和22%,而黑藻在中营养水平下单株最大生物量较富营养水平下低了51%,表明狐尾藻和金鱼藻在中营养水平下的生长较黑藻好.通过对3种沉水植物可溶性蛋白和叶绿素质量分数的分析发现,黑藻在中富两种营养水平下,质量分数较低且波动平稳,金鱼藻和狐尾藻可溶性蛋白和叶绿素质量分数持续升高,表明这两种沉水植物对水体中营养盐的耐受能力较黑藻强.金鱼藻超氧歧化酶(SOD)活性、过氧化物酶(peroxidase)活性和丙二醛(MDA)含量在试验后期上升速度加快,且富营养水平下金鱼藻MDA质量分数的最大值是中营养水平下最大值的5倍,表明在中营养水平下金鱼藻已经受到明显胁迫,而在富营养水平下受到胁迫更为显著.在本试验条件下,黑藻生物量小,而金鱼藻SOD活性、POD活性和MDA质量分数变化幅度大,在试验后期急速上升,表明这两种沉水植物受到的营养盐胁迫较狐尾藻大,而狐尾藻在中营养水平下的耐营养盐胁迫能力较强.     

Effects of the interactions between selenium and phosphorus on the growth and selenium accumulation in rice (Oryza sativa)

The solution culture, paddy soil culture and the simulation experiments in the laboratory were conducted to clarify the interactions between selenium and phosphorus, and its effects on the growth and selenium accumulation in rice. Results revealed that a suitable supply of selenium could promote rice growth and excessive selenium could injure rice plant, causing lower biomass, especially in the roots. The supply of selenite could enhance the selenium contents of rice shoots and roots in solution culture and in soil culture. The selenium concentrations in roots were much higher than those in shoots supplied with the same rates of selenium and phosphorus. The interaction between selenium and phosphorus was evident. When the phosphorus supply increased to meet the needs of plant growth, phosphorus could promote absorption and accumulation of selenium in the shoots. If the phosphorus supply was excessive, phosphorus could inhibit the accumulation of selenium in the shoots at the lower selenite level (2 micromol l(-1)), but could not at the higher selenite level (10 micromol l(-1)). With the supply of phosphate increased, the selenium concentrations in the roots decreased significantly at both selenite levels. The presence of phosphate could decrease Se sorption on the soil surface and increase the selenium concentration in the soil solution. The concentrations of selenium in shoots and roots supplied with 0.08 g kg(-1) phosphorus were lower than those with no phosphorus supplied. With the increase of phosphorus added to 0.4 g kg(-1), the selenium concentration in shoots and roots increased. The effect of phosphorus on the concentration was statistically significant at all three selenium levels.     

Effects of the Interactions Between Selenium and Phosphorus on the Growth and Selenium Accumulation in Rice (Oryza Sativa)

The solution culture, paddy soil culture and the simulation experiments in the laboratory were conducted to clarify the interactions between selenium and phosphorus, and its effects on the growth and selenium accumulation in rice. Results revealed that a suitable supply of selenium could promote rice growth and excessive selenium could injure rice plant, causing lower biomass, especially in the roots. The supply of selenite could enhance the selenium contents of rice shoots and roots in solution culture and in soil culture. The selenium concentrations in roots were much higher than those in shoots supplied with the same rates of selenium and phosphorus. The interaction between selenium and phosphorus was evident. When the phosphorus supply increased to meet the needs of plant growth, phosphorus could promote absorption and accumulation of selenium in the shoots. If the phosphorus supply was excessive, phosphorus could inhibit the accumulation of selenium in the shoots at the lower selenite level (2 mol l^–1), but could not at the higher selenite level (10 mol l^–1). With the supply of phosphate increased, the selenium concentrations in the roots decreased significantly at both selenite levels. The presence of phosphate could decrease Se sorption on the soil surface and increase the selenium concentration in the soil solution. The concentrations of selenium in shoots and roots supplied with 0.08 g kg^–1 phosphorus were lower than those with no phosphorus supplied. With the increase of phosphorus added to 0.4 g kg^–1, the selenium concentration in shoots and roots increased. The effect of phosphorus on the concentration was statistically significant at all three selenium levels.     

磷肥和黑麦草结合修复铅污染贫磷潮土的研究（Remediation of Lead Polluted Chaotu Soil with Low Phosphorus Availability by Phosphorus Fertilizer Amendment and Ryegrass）

在Pb污染土壤中施用磷肥是降低Pb有效性的有效方法.在低磷或高Pb胁迫下,植物根际的一系列变化将促进植物对磷的吸收或对Pb毒性的降低,但低磷胁迫下植物对土壤Pb有效性的影响研究不多.为探讨Pb污染低磷土壤上施用磷肥对Pb有效性、植物吸收Pb的影响及黑麦草(LoliumperenneL.)对土壤Pb有效性的影响,设置0、500和1000mg·kg-13个Pb用量和0、2729mg·kg-1两个普通过磷酸钙磷肥用量,种植黑麦草,0和1000mg·kg-1Pb下设置不种植植物的对照的盆栽试验,植物生长48d后收获,测定植物地上部和根系产量、长度、Pb浓度及土壤DTPA-Pb含量.结果表明,施用磷肥后植物产量和地上部长度增加、根冠比、根系长度和Pb浓度减小,500mg·kg-1Pb用量时,未施用磷肥和施用磷肥时植物产量分别为0.37和1.70g·pot-1,1000mg·kg-1Pb用量时这两个数值分别为0.24和1.50g·pot-1,500mg·kg-1Pb用量时,植物产量与未施Pb处理(产量为0.75g·pot-1)差异显著(p<0.05);施用磷肥后,地上部吸收的Pb的比例和植物体吸收的Pb数量均增加.1000mg·kg-1Pb用量下,植物产量、地上部长度均小于500mg·kg-1Pb用量处理时的水平,而土壤DTPA-Pb浓度、植物Pb浓度、Pb吸收量均大于500mg·kg-1Pb处理,表明2729mg·kg-1普通过磷酸钙用量并不能完全抵消1000mg·kg-1Pb对植物生长的抑制作用.施用磷肥降低了土壤DTPA-Pb含量,但500mg·kg-1Pb用量时降低效果不显著(p>0.05).0mg·kg-1Pb用量下,种植植物的处理土壤DTPA-Pb含量比未种植植物处理高54.3%;1000mg·kg-1Pb处理时,种植植物处理土壤DTPA-Pb含量比未种植植物平均低18.5%.以上结果表明,在0mg·kg-1Pb用量下,植物生长受到了一定程度的磷胁迫.在磷胁迫下,种植植物提高了土壤Pb有效性,而在1000mg·kg-1Pb用量下,不管是否施用磷肥,种植植物均降低了土壤Pb有效性.本研究结果表明,在低磷和高Pb胁迫下,施用水溶性磷肥可降低土壤Pb有效性,促进黑麦草生长,促进Pb向植物地上部转移;在低磷胁迫且无Pb污染条件下,黑麦草对土壤Pb的有效性表现为促进;在高Pb胁迫下,不管是否施用磷肥,黑麦草均可降低土壤Pb有效性.     

Duckweed Landoltia punctata purifies micro-polluted surface water and produces starch北大核心CSCD

Aquatic plant duckweed has remarkable potential in nutritional water purification and starch accumulation; at present, it has received increasing attention. This study aimed to investigate the ability of duckweed in nutrient recovery from micro-polluted surface water; further, the starch accumulation capacity of duckweed was evaluated. The results showed that duckweed can achieve better depth treatment of the micro-polluted surface water, within 1-day treatment, by duckweed. Ammonia nitrogen and total phosphorus status of Class V and worse than class V water was improved to a superior level; moreover, the nitrogen and phosphorus removal rates were 98.5% and 82.9%, respectively. In addition, duckweed can rapidly accumulate starch during water treatment. The starch content of duckweed was 28.38% and 21.57% (dry weight) in Class V and worse than class V wastewater after 3 days of treatment, respectively, and reached 52.15% and 49.58% on day 15. Moreover, additional carbon dioxide (CO2) supplementation promoted the starch production. The starch content increased by 55.7% compared with that of control, and the average starch accumulation rate increased by 2.72 times in 3 days. Therefore, duckweed can not only rapidly purify micro-polluted water, but also accumulate a large amount of starch. This study forms the basis for wastewater treatment and post-treatment utilization of duckweed biomass. © 2018 Science Press. All rights reserved.     

不同磷初始浓度对紫萍生长及磷吸收效率的影响

采用室内模拟培养试验方法,研究不同磷初始浓度对紫萍生长及磷吸收效率的影响。结果表明,水体初始ρ（磷）为3.0 mg.L-1时,紫萍相对生长率最高,生长繁殖速度最快。当初始ρ（磷）为0.3～3.0 mg.L-1时,紫萍对水体中磷的去除率在70%以上。紫萍累积吸磷量和磷吸收能力均随磷初始浓度的升高而增加,但当初始ρ（磷）为45.0 mg.L-1时,紫萍累积吸磷量和单位鲜质量紫萍吸磷量均明显下降。当初始ρ（磷）≤1.5 mg.L-1时,紫萍体内酸性磷酸酶活性升高,但随着低磷胁迫时间的延长,低磷条件和高磷条件间酸性磷酸酶活性差异减小。     

镉对籽粒苋耐性生理及营养元素吸收积累的影响

初步阐明了镉对籽粒苋耐性生理及营养元素吸收积累的影响,为进一步揭示籽粒苋的镉耐性与镉富集机理奠定了基础。通过对生物量的监测,对叶绿素、蛋白质、游离氨基酸、大量元素及微量元素等的含量的测定,阐明镉胁迫对籽粒苋生长生理、抗胁迫耐性、营养元素吸收分配的影响。研究结果显示,镉胁迫对籽粒苋的生长抑制作用不明显,植株生物量随着镉浓度的提高而轻微降低。随着镉处理浓度的提高,叶绿素含量下降幅度显著;蛋白质和游离氨基酸含量变化幅度不明显;钾含量无大幅变化;镉、磷、钙、镁、锌、铁、锰、铜含量变化幅度较显著。镉、钾、磷、锰的迁移系数随着镉处理浓度的提高无显著变化;钙的迁移系数呈上升趋势;镁、锌、铁、铜的迁移系数均呈下降趋势。这些结果表明：镉胁迫降低籽粒苋叶绿素含量,抑制植株光合作用,继而抑制了植株的生长,但其程度不明显;镉胁迫条件启动活性氧防御机制;引起植株体内部分养分代谢紊乱。结论：低浓度镉处理条件下,籽粒苋受镉离子影响,抗氧化能力下降。在高浓度镉处理条件下,籽粒苋调节了营养元素的吸收和分配,启动了一系列活性氧防御机制,提高了抗胁迫能力。     

锌、镉复合污染对重金属蓄集植物黑麦草养分吸收及锌、镉积累的影响

采用根袋盆栽试验研究了锌、镉单一及复合污染对重金属蓄集植物黑麦草(Lolium perenne L．)生长、养分吸收及锌、镉积累的影响．结果表明,锌、镉单一及复合污染对黑麦草生物量存在不同程度的抑制作用．锌、镉单一及复合污染均明显降低了黑麦草植株N、P、K含量,以锌、镉复合污染对植株养分吸收的抑制作用最大．锌、镉污染共存下,黑麦草对锌、镉的吸收为协同效应．黑麦草吸收的锌、镉主要集中在地上部,以锌、镉复合污染植株对锌、镉的蓄集量最大,其地上部锌、镉含量分别达到3108．72、73．97 mg·kg-1．     

The Role of Macrophytes in the Retention of Phosphorus in the River Thame,England

The effects of the growth of the dominant species of macrophytes on phosphorus transport in the River Thame, a nutrient enriched lowland clay catchment in southern England, were assessed using a mass-balance approach. Macrophyte abundance was estimated between late March and early June at three sites along the river. the plant biomass of phosphorus and the total phosphorus content of sediments in the main part of the river channel and sediments associated with the plant roots were measured on each occasion. Total phosphorus concentrations in the river water were measured at weekly intervals at a gauging station at the lower end of the study reach.

The results showed that the phosphorus content of plants at the site most impacted by sewage derived phosphorus was < 1% of the flux of total phosphorus estimated for the water column in April and May. Phosphorus contained in the total standing crop of macrophytes at the least impacted site was estimated as approximately 3% of the mean daily flux of total phosphorus in the water. Although no trends were found in the total phosphorus contents of the roots, shoots or sediments through the season, differences in the phosphorus content of the sediments were found between sites with different phosphorus loading. Higher porewater and Equilibrium Phosphate Concentrations (EPC_oS) were recorded at the site most impacted by sewage effluent when compared to an upstream sampling site.