镉与萘复合胁迫对红树植物白骨壤幼苗萌芽及生长的影响

为探讨白骨壤(Avicennia marina)幼苗对重金属镉(Cd)和多环芳烃萘(Nap)复合胁迫的响应,采用砂基栽培,对其幼苗的萌芽和生长进行了研究。结果表明,Cd、Nap复合胁迫对白骨壤萌芽的抑制效应较单一胁迫明显,胁迫前期幼苗成活率提高,胁迫后期则降低。胁迫栽培45 d,10 mg L~(–1)的Nap在叶形态、茎高及各器官生物量上能够减轻Cd胁迫的影响,但增强对根长的抑制作用,10 mg L~(–1) Nap-25 mg L~(–1) Cd处理的叶面积、叶长、叶宽、茎高及全株生物量分别比25 mg L~(–1) Cd处理的提高9.6%、7.9%、7.4%、5.1%和20.2%,但根长则比150 mg L~(–1) Cd处理的下降11.1%。至胁迫栽培90 d,各处理间幼苗器官及全株生物量无显著影响,复合胁迫对叶形态、茎高和根长等的抑制作用要强于单一Cd胁迫。因此,随着复合胁迫时间的延长,Cd和Nap对白骨壤幼苗的生长由拮抗效应转变为协同效应。     

重金属镉对红树植物白骨壤和桐花树幼苗生理特性的影响

通过砂泥栽培实验研究了红树植物桐花树和白骨壤幼苗在含Cd 0.6～30 mmol·L~(-1)系列海水培养液中某些生理特性的变化。当培养液中Cd浓度为0.6 mmol·L~(-1)时桐花树和白骨壤幼苗生长正常,叶绿素含量和光合速率变化不大。当高于12 mmol·L~(-1)时,除桐花树和白骨壤幼苗除POD酶活性越来越高之外,叶绿素含量、光合速率、SOD、CAT酶活性均不断减弱,而且浓度愈高,这些指标下降愈大。结果表明Cd对红树植物桐花树和白骨壤幼苗具有毒害作用,Cd浓度愈高对其毒害愈严重,两种红树植物比较,桐花树抗重金属镉毒害的能力大于白骨壤。     

红树植物白骨壤叶片的解剖结构及其生态适应性

运用石蜡切片的方法对红树植物白骨壤的叶片进行解剖学的观察和研究。结果表明:白骨壤的叶为异面叶;上表皮为复表皮,有厚的角质膜及下皮层;下表皮上有大量的泌盐腺毛;栅栏组织多层,约占叶肉组织的2/3,海绵组织退化;机械组织和输导组织均很发达。反映了白骨壤叶片的结构与其生活的海生环境高度相适应。     

人工污水对白骨壤幼苗生理生态特性的影响

探讨了3种不同浓度污水对白骨壤幼苗叶片叶绿素含量、过氧化氢酶活性、游离脯氨酸含量、含水量、相对电导率与植株生物量、茎径和茎高生长量等生理生态指标的影响。结果表明,正常浓度和5倍浓度污水对植株无不良影响,并可促进植株生长;10倍浓度污水对植株各生理生态指标有显着影响,但植株最终可维持正常生长。研究表明,白骨壤对污水具有较强的适应性和耐受性。     

汞胁迫对白骨壤(Avicennia marina)幼苗生理生态的影响

为了解红树植物的重金属抗性机制,对白骨壤(Avicennia marina)幼苗进行不同浓度Hg2+(1、5、10、50、100 mg·L-1)的胁迫实验,测定并分析了Hg2+胁迫对白骨壤幼苗叶片的光合作用和抗氧化酶活性的影响.结果表明:叶片净光合速率随着胁迫时间的延长而降低,高浓度(≥150 mg·L-1)Hg2+胁迫下叶片的净光合速率低于中低浓度胁迫,且高浓度胁迫的叶片净光合速率在48 h后快速下降;叶片净光合速率与胞间二氧化碳浓度呈极显著负相关,叶绿素含量随Hg2+浓度的增加而降低.气孔导度在不同浓度胁迫下反应不同,低浓度Hg2+对白骨壤幼苗光合的影响可能是气孔因素,中高浓度Hg2+对白骨壤幼苗光合作用的抑制主要是非气孔因素.低浓度Hg2+胁迫,白骨壤幼苗叶片SOD、POD活性升高,表现了一定的抗逆性,而高浓度表现为抑制作用,基本在100 mg·L-1 Hg2+胁迫下活性达到最低值.说明Hg2+可以抑制白骨壤叶片的光合活性,高浓度Hg2+胁迫削弱了白骨壤的活性氧清除能力,植物极易受到伤害.     

污水排放对白骨壤凋落叶的影响

一年中白骨壤各处理组凋落叶总生物量大小顺序为FW >NW >CL >TW ;白骨壤各污水处理组凋落叶含N量和含P量均比对照组稍高 ,随污水浓度的上升含N量和含P量呈上升趋势 ;一年中白骨壤植物凋落叶N、P、Zn的含量的多少顺序都为 :FW >NW≈TW >CL ,Cd、Ni、Pb的含量的多少顺序为FW >TW >NW >CL ,各处理组凋落叶重金属的含量都以FW最高 ;各处理组植株元素年归还率平均为 :N 1 9 1 % ,P 2 1 3% ,Cd 2 1 2 % ,Ni2 1 4 % ,Pb 2 3 3% ,Zn 31 5 % ,归还量均较低。     

重金属铬(Ⅲ)对红树植物白骨壤幼苗生长的影响

采用砂基栽培,研究重金属铬(Ⅲ)不同胁迫强度(0、100、200、300、400、500、600、800 mg·L-1)和胁迫时间(25、45和150 d)条件下,对红树植物白骨壤(Avicennia marina)成熟胚轴萌发及幼苗生长的影响.结果表明:Cr(Ⅲ)胁迫(0～800 mg·L-1)对白骨壤成熟胚轴的初期萌发无明显的影响.胁迫栽培45 d时,随着Cr(Ⅲ)浓度的提高,白骨壤幼苗苗高生长、根系生长及各组分生物量和总生物量均表现出逐渐下降的趋势,但下降幅度不大.当胁迫时间延长至150 d时,Cr(Ⅲ)浓度在100 mg·L-1时对幼苗的生长影响不明显,而浓度在100 mg·L-1以上,达到200 mg·L-1以上水平,则对幼苗根系生长、苗高、叶片大小及生物量生长均具有明显抑制的作用,并将随胁迫时间的增加而加剧.     

大亚湾红树林研究Ⅲ．白骨壤和秋茄叶片2种酶活性及过氧化物酶同工酶谱

研究了大亚湾附近澳头,稔山与三门岛地区生长的白骨壤,秋茄叶片多酚氧化酶,过氧化物酶的活性与过氧化物酶同工酶谱,发现2种红树植物叶片中多酚氧化酶活性在澳头,稔山,三门岛3个地区依次降低,而过氧化物酶活性则与之相反,依次升高,过氧化物酶同工酶谱在不同地区表现出峰高及区带数上的判别,但无地区规律性。     

挖捕泥丁对红树植物白骨壤幼苗生长影响的模拟

沿海群众为了增加收入挖掘林下滩涂海洋经济动物可口革囊星虫,这是导致中国红树林退化的一个重要原因.本文研究了挖掘深度、弧度和频率3个因素对1年生白骨壤幼苗的苗高、基径、单叶面积、比叶面积、生物量和死根干质量等生长指标的影响,了解挖掘活动对红树林生长的影响机理,并筛选出红树林健康状况的评估指标.结果表明:挖掘活动使白骨壤幼苗的苗高和基径增长量、单叶面积、比叶面积和生物量显著减少,而死根干质量显著增加;挖掘深度和弧度对幼苗生长具有明显影响,但频率的影响不显著;当挖掘深度＜5 cm、弧度＜240°、每月2次以下时,对幼苗的伤害较轻,而挖掘深度＞5 cm则会对幼苗造成严重影响.     

镉在白骨壤模拟湿地系统中的分布、迁移及净化效应

在温室中建立红树林植物白骨壤模拟湿地系统,分别用正常(C₁)、5倍(C₅)和10倍(C₁₀)3种人工配置的不同浓度的污水每周定时定量对模拟系统污灌1年,研究重金属Cd的分布、迁移以及系统对Cd污染的净化效果.结果表明,由人工污水加入系统中的Cd主要存留在土壤子系统中(87.67%～96.74%),只有很少部分迁移到植物体和凋落物中,约占总加入量的0.43%～3.23%;白骨壤植物各器官中Cd含量在根中最高;模拟系统对污水中Cd的净化效果显著,在植物-土壤系统中,正常、5倍和10倍浓度组的净化率分别为90.43%、97.17%和97.06%,在无植物系统中,对应组分别为93.29%、93.10%和90.4%.     

Accumulation and speciation of Cd in Avicennia marina tissues

Avicennia marina is a high-Cd-tolerant species in the mangrove wetlands. A hydroponic experiment was carried out to research the accumulation and chemical form distribution of Cd in the tissues of A. marina under different concentrations and durations of Cd stress. It was found that the concentrations of Cd in plant tissues followed the order of root > stem > leaf. The data suggested that root activity decreased, Cd accumulation ability weakened in roots, and the translocation factor increased in stems and leaves with the increase of stress duration. With a proactive defense mechanism, most Cd was bound to pectates, organic acids, and protein, especially in roots and stems with the most proportion of 88.51 and 78.91%, respectively, having lower biological activities. The Cd bounded to water-soluble organic acid and free inorganic aminophenol–Cd showed the lowest concentration. The pectates, organic acids, and protein-integrated Cd seem the most important in affecting Cd detoxification for A. marina; this mechanism of change in Cd biological activities decreases the toxicity of this aggressive pollutant and presents new knowledge about the tolerance of mangrove plants.     

白骨壤幼苗的形态特征及其生物量

白骨壤1年生幼苗的株高、基径、根长、呼吸根高、叶面积以及根、茎、枝、叶、胎生苗和全株生物量等计量指标,呈现算术平均值>中值>众值组段中点的规律,符合正偏态分布节数、叶数、呼吸根数、胎生苗数等计数指标的算术平均值和中值相等,二者大于或等于众值组段中点.研究发现白骨壤1年生幼苗能生长指状呼吸根以及开花、结果和发育胎生苗,而且胎生苗成熟后直接萌发形成新的幼苗.根据实测的数据,采用一元线性回归、多元线性回归和非线性回归拟合了白骨壤1年生幼苗主要形态因子和生物量的回归模型.     

Factors contributing to dwarfing in the mangrove Avicennia marina

BACKGROUND AND AIMS: In Richards Bay, South Africa, Avicennia marina frequently exhibits a distinct productivity gradient, with tree height decreasing markedly from 6-10 m in the fringe zone to <1.5 m in the dwarf zone which is 120 m inland at a slightly higher elevation. In this investigation, soil physico-chemical conditions between fringe and dwarf A. marina were compared and the constraints imposed by any differences on mangrove ecophysiology and productivity determined. METHODS: Soil and plant samples were analysed for inorganic ions using spectrophotometry. Gas exchange measurements were taken with an infrared gas analyser and chlorophyll fluorescence with a fluorometer. Xylem psi was determined with a pressure chamber and chlorophyll content with a chlorophyll absorbance meter. RESULTS: In the dwarf site, soil salinity, total cations, electrical conductivity and soil concentrations of Na(+), K(+), Ca(2+), Mg(2+), Zn(2+), Mn(2+) and Cu(2+) were significantly higher than those in the fringe zone. Soil water potential and the concentration of soil P, however, were significantly lower in the dwarf site. In the leaves, Na(+) was the predominant ion and its concentration was 24 % higher in dwarf than fringe mangroves. Leaf concentrations of K(+), Ca(2+), Mg(2+), Mn(2+) and P, however, were significantly lower in dwarf mangroves. Photosynthetic performance, measured by gas exchange and chlorophyll fluorescence, was significantly reduced in the dwarf plants. CONCLUSIONS: The results suggest that hydro-edaphic factors contribute to high soil salinities, low water potentials, water stress and ion imbalance within tissues including P deficiency, which in interaction, contribute to dwarfing in Avicennia marina.     

中国北部湾白骨壤红树林的虫害与研究对策

危害北部湾白骨壤的主要害虫是广州小斑螟 (Oligochroacantonella)幼虫、双纹白草螟 (Pseudcatharylladuplicella)幼虫和广翅蜡蝉 (Euricaniasp.)成虫。广州小斑螟喜食害白骨壤叶片 ,造成大量叶片的枯干和枝条的死亡 ,最高可导致林木 73 %的叶面积危害。室内培养发现广大腿小蜂 (Brachymeriasp .)、啮小蜂 (Tetrastichussp .)可寄生广州小斑螟的蛹 ,终止其羽化过程。虫害具有突发性、专一性、快速扩展的特点。海水淹没可明显抑制虫害。讨论了虫害的发源、爆发的原因、生态效应和防治途径 ,并指出深入研究的方向     

Microsatellite analysis of genetic structure in the mangrove species Avicennia marina (Forsk.) Vierh. (Avicenniaceae)

The level of genetic variation throughout the entire worldwide range of the mangrove species Avicennia marina (Forsk.) Vierh. was examined using microsatellite markers. Three microsatellite loci detected high levels of allelic diversity (70 alleles in total), essential for an accurate estimation of population genetic parameters. The informativeness of the microsatellite loci tended to increase with increasing average number of repeats. The levels of heterozygosity detected for each population, over all loci, ranged from 0.0 to 0.8, with an average of 0.407, indicating that some populations had little or no genetic variation, whereas others had a large amount. Populations at the extremes of the distribution range showed reduced levels of heterozygosity, and significant levels of inbreeding. This is not unexpected as these populations may be subject to founder effects and environmental constraints. The presence of genetic structure was tested in A. marina populations using three models: (i) a single panmictic model; (ii) the discrete subpopulation model; and (iii) the isolation by distance model. The discrete subpopulations model was supported by the overall measures of population differentiation based on the infinite alleles model (F-statistics), and the stepwise mutation model (R statistics). In addition, an analysis of molecular variance (AMOVA), using both theoretical models, found that most of the variation was between populations (41-71%), and within individuals in the total population (31-49%). There was little variation among individuals within populations (0-10%). There was no significant isolation by distance. The high levels of genetic differentiation observed among populations of A. marina may be due to environmental and ecological factors, particularly past sea level and climatic changes.