秋茄(Kandelia candel)幼苗对多氯联苯污染的生理生态响应

通过盆栽实验,研究了4种不同浓度(180、900、1800和2700μg kg-1)的多氯联苯(PCBs)对红树植物秋茄幼苗的茎高、茎径、生物量、相对生长速率以及叶片的叶绿素含量、水势、丙二醛含量和游离脯氨酸含量等生理生态指标的影响,结果表明:(1)在所设PCBs浓度范围内,PCBs对秋茄幼苗的茎高、茎径、生物量和相对生长速率等生长指标的生长没有产生不利的影响,相反具有促进作用,红树植物秋茄在PCBs污染情况下能旺盛生长;(2)在所设PCBs浓度范围内,秋茄幼苗叶片能保持相对正常的叶绿素水平和相对稳定的叶绿素a/b值,叶绿素a、叶绿素b和叶绿素a+b的含量虽然有所降低,但均为对照的70%以上;叶绿素a/b值有所升高,但均未超过对照的15%。(3)随着PCBs浓度的升高,秋茄幼苗叶片水势呈上升趋势,而游离脯氨酸含量和膜质过氧化产物MDA含量均有一定的增加,说明PCBs对秋茄幼苗产生了一定的影响。总体来看,秋茄幼苗能在所设浓度的PCBs范围内正常生长,对PCBs有较强的耐受性和适应性,对PCBs污染的沉积物进行修复是可行的。

淹水胁迫对秋茄(Kandelia candel)幼苗叶片C、N及单宁含量的影响——一个关于碳素-营养平衡假说的实验

通过在福建厦门同安湾潮间带滩涂种植红树植物秋茄,测定不同滩面高程(黄海高程1.6,1.0,0.4m)下1年生秋茄幼苗叶片单宁、C、N、叶绿素含量及幼苗的生长指标,研究了淹水胁迫对秋茄幼苗次生代谢物质单宁的影响及作用机理。结果表明,随着滩面高程的降低,淹水胁迫增强,秋茄幼苗生物量、叶片C/N及单宁含量显著降低,在滩面高程0.4m处,与1.0m和1.6m相比,幼苗生物量分别降低了18.2%和47.0%,叶片C/N比值分别降低了17.5%和20.0%,相应地,叶片单宁含量也分别降低了44.6%和70.5%。秋茄幼苗叶片单宁含量与叶片C/N比值呈显著正相关(R=0.8425),表明秋茄幼苗叶片中C、N含量及单宁含量对淹水胁迫的响应符合碳素/营养平衡假说。

秋茄(Kandelia candel)胚轴阴干过程中单宁的动态变化

对红树植物秋茄(Kandeliacandel)成熟胚轴进行30d阴干处理,每隔3d测定含水量、总多酚、可溶性缩合单宁、蛋白质结合缩合单宁和纤维素结合单宁.探讨了缩合单宁与蛋白质,纤维素结合的动态变化.结果表明:1)胚轴含水量由最初的60.36%以线性模式减少到45.38%,保水抗旱能力较强;2)干旱处理过程中的繁殖体的总多酚的含量在12.13%～15.49%之间,变化不显著,这与叶片等凋落物酚类物质迅速被淋溶、氧化和分解不同,酚类物质在完整的有生活力的胚轴中得以保存,可溶性缩合单宁因为与蛋白质及纤维素结合,转化为结合的缩合单宁;3)与蛋白质结合的单宁在阴干处理18d后迅速增加,活的植物组织具有某种机制阻止单宁与蛋白质结合,随着胚轴的失活,这种机制也逐渐解除.纤维素结合的缩合单宁变化与蛋白质结合的缩合单宁大致相同.

多氯联苯(PCBs)污染对秋茄Kandelia candel生长的影响

通过盆栽实验研究了不同浓度(180×10-9、900×10-9、1800×10-9和2700×10-9)的多氯联苯(PCBs)对红树植物秋茄Kandelia candel幼苗生长的影响。结果表明:秋茄的生长指标茎高、茎径、茎体积和生物量的生长量呈现先上升后下降的变化趋势,不过各处理的生长指标均高于对照组;研究表明,秋茄能在PCBs浓度为2 700×10-9的沉积物中正常生长,对PCBs有较强的耐受性和适应性。

Influence of water logging time on the growth of Kandelia candel seedlings

Influence of waterlogging time on the growth of Kandelia candel(L.) Druce seedlings grown for 70 d in the artificial- tidal tanks' simulated semidiurnal tide under greenhouse is studied. Sand and soil act as the substrate and artificial seawater with salinity of 15 is used in cultivation. Shorter waterlogging time(inundated for about 2 ~ 4 h) promotes the growth of K. candel seedlings, while longer time(inundated more than 8 h) or no waterlogging(0 h) inhibits their growth. The number and length of aerating roots increase with the increase of waterlogging time. Under existing conditions, the optimal waterlogging time for the growth of K. candel seedlings is about 2 ~ 4 h in every tide cycle. Compared with other treatments, the 2 h sanded treatments obtain the highest biomass of seedlings, have the lowest mass loss of hypocotyl and broaden the photosynthetic area by increasing the area per leaf after 70-d cultivation. And the soil treatments have the similar tendency. However, waterlogging for 8 h in every tide cycle is critical for normal development of seedlings.K. candel seedlings are highly tolerant to waterlogging and a proper waterlogging is beneficial to the growth of K. candel seedlings.

秋茄(Kandelia candel(L))根系分泌低分子量有机酸及其对重金属生物有效性的影响

应用电感耦合等离子体质谱(ICP-Ms)与高效液相色谱(HPLC)分别对福建漳江口红树林湿地不同土壤结构(砂质与泥质)根际与非根际沉积物中重金属(Cu,Pb,Cd,Zn)含量,以及生长于砂质与泥质滩涂上的红树植物秋茄(Kandelia candel(L)Druce))幼苗根系分泌物中的低分子量有机酸进行测定。在室内模拟秋茄根系分泌的低分子量有机酸,作为重金属提取剂提取沉积物中可溶解态与碳酸盐结合态重金属,并与欧盟标准物质局(BCR)连续提取法相比较,探讨红树根系分泌的低分子量有机酸对红树林沉积物重金属生物有效性的影响。研究结果表明:漳江口红树林泥质沉积物中重金属含量大于砂质沉积物,根际沉积物大于非根际沉积物。两样地沉积物中重金属的赋存形态主要以铁锰氧化物结合态为主,根际沉积物中可交换态与碳酸盐结合态重金属含量均大于非根际沉积物。秋茄根系分泌低分子量有机酸为甲酸,丁酸,苹果酸,柠檬酸,乳酸。不同土壤结构对秋茄根系分泌的苹果酸,柠檬酸,乳酸有显著影响(P<0.05)。以低分子量有机酸作为提取剂对沉积物中可溶解态与碳酸盐结合态重金属的提取率表现为:柠檬酸>混合酸>苹果酸>乳酸>乙酸,低分子量有机酸对红树林沉积物重金属的生物有效性有促进作用。

九龙江口秋茄(Kandelia candel)红树林掉落叶自然分解与落叶腐解微生物的关系

通过对九龙江口秋茄红树林人工模拟凋落叶自然分解过程中落叶腐解与落叶腐解微生物变化的研究,结果表明: 1.随落叶分解进程,落叶腐解微生物数量有了显著地变化;就细菌、放线菌和丝状真菌等三大类群微生物数量来看,整个过程以细菌占绝对优势,其数量在200×10~4-8800×10~4个/克干重,占三大类群微生物总数量的96-99％以上。这表明细菌是落叶分解起主要作用的微生物类群。 2.微生物各生理类群中,以氨化细菌数量最多,在26×10~4-180×10~4个/克干重;而亚硝化细菌,反硝化细菌及纤维分解菌分别仅在0.03×10~4-0.24×10~4,0.03×10~4-0.10×10~4及1.14×10~4-7.33×10~4个/克干重。表明氨化细菌是有机物质无机化的主要生理类群。并且氨化作用、亚硝化作用和反硝化作用是同时进行;并随落叶腐解周期的延长(半腐解周期内)而加强,唯强度不一,它反映了该生境干、湿交替的沼泽化特点。纤维分解菌数量的变化较特殊,在落叶腐解第2周时,有了明显增多,至第4周达全周期的最高值,而以后周期都与初始叶面纤维分解菌的数量相(?),甚至减少。从微生物活性的变化测定结果来看,与上述微生物生理类群的变化特点是相一致的。 3.在该生境中,落叶腐解速度是很快的,当落叶入土1周后将近1/4有机物被腐解,至第6周达半腐解状态。随落叶腐解有机物质无机化程度的加速,残叶中单位叶重的可溶性总糖含量和全磷量都明显地减少,而全氮含量显著地增加。

Changes of plasma membrane ATPase activity, membrane potential and transmembrane proton gradient in Kandelia candel and Avicennia marina seedlings with various salinities

The salt-secreting mangrove, Avicennia marina, and non-salt-secreting mangrove, Kandelia candel were cultivated in sand with various salinities(0‰, 10‰, 20‰, 30‰, 40‰) for 60 d. Plasma membrane vesicles of high-purity in leaves and roots of A.marina and K. candel seedlings were obtained by two-phase partitioning. The function of the plasma membranes, the activity of ATPase, membrane potential and transmembrane proton gradient, at various salinities were investigated. The results showed that within a certain range of salinity(A. marina and roots of K. candel: 0—30‰; leaves of K.candel: 0—20‰), the activity of ATPase increased with increasing salinity, while high salinity(above 30‰ or 20‰) inhibited ATPase activity. In comparison with A. marina, K. candel appeared to be more sensitive to salinity. The dynamics of membrane potential and transmembrane proton gradient in leaves and roots of A. marina and K. candel seedlings were similar to that of ATPase. When treated directly by NaCl all the indexes were inhibited markedly: there was a little increase within 0—10‰(K. candel) or 0—20‰(A. marina) followed by sharp declining. It indicated that the structure and function of plasma membrane was damaged severely.

闽东秋茄(Kandelia candel)人工林与天然林异龄叶性状比较

比较闽东不同生境秋茄[Kandelia candel(Linn.)Druce]人工林与天然林异龄叶性状间的相互关系,结果显示:(1)2种林分的秋茄林叶MLA、SLA和LDMC,当年生均大于往年生,分别为MLA(38.4 cm^2>36.0 cm^2)、SLA(78.9 m^2/kg>67.5 m^2/kg)、LDMC(258.7 mg/g>193.8 mg/g);(2)当年生和往年生叶MLA人工林均大于天然林,分别为当年生(40.7 cm^2>36.1 cm^2)、往年生(37.5 cm^2>34.4 cm^2)。当年生叶SLA人工林小于天然林,为(78.4 m^2/kg<79.4 m^2/kg),往年生叶SLA人工林大于天然林,为(71.0 m^2/kg>64.0 m^2/kg)。当年生与往年生叶LDMC人工林均大于天然林,分别为当年生(344.4 mg/g>173.0 mg/g)、往年生(225.6 mg/g>162.0 mg/g)。研究表明,异龄叶对光资源获取和储存物质以构建叶器官这2种投资策略的权衡,是植物在各自生境中适应性进化的结果。秋茄能对生境因子胁迫调整生活策略应对,具有较强的环境适应性,适宜作为海岸防护林树种人工栽植。

Accumulation of polycyclic aromatic hydrocarbons from contaminated soil by Kandelia candel

The purpose of this study was to investigate the accumulation behavior of two typical PAHs, phenanthrene （PHE） and fluoranthene （FLA）, uptaken by the mangrove Kandelia candel in various treated sandy soils. The experiment lasted for three months. Soil and plant samples were collected after 3, 6, 9 and 13 weeks of the incubation and the levels of PAHs were analyzed using a GC/MS （HP6890-5975B）. The results showed that the root accumulations of PHE and FLA were elevated with the increase of the PAH concentrations in the soil. With prolonged exposure time, PHE and FLA concentrations of the roots increased significantly in comparison with the control. PHE and FLA concentrations of root after 13 weeks of treatment ranged from 0.28 to 4.36 #g.g-1 and 0.79 to 35.76 pg.g 1 respectively. The calculated mean values of the root concentration factors were 0.58 for PHE and 0.71 for FLA. This indicated that root accumulation of FLA was greater than PHE, which would result from the higher octanol-water partition coefficient （Kow） of FLA. These results underline the ability of mangroves to remove PAHs from contaminated marine substrates and hence their potential use in bioremediation and the removal of PAHs from the marine food chain.

CANDELS巡天简介

CANDELS巡天是哈勃空间望远镜历史上最大的多波段图像观测项目,其科学目标主要是借助高分辨率WFC3(Wide Field Camera 3)/近红外波段图像数据,研究高红移(z>1)星系的形成与演化。CANDELS巡天包含5个观测区域,总面积约800平方角分。独一无二的空间条件和很深的图像深度已使CANDELS在天体物理学领域取得越来越多重要的科学成果。根据国内相关研究者的需要,该文对CANDELS巡天的观测、数据结构、图像数据预处理给予简要的介绍,以使国内感兴趣的同仁对该巡天项目有初步的了解。

秋茄(Kandelia candel L.)响应重金属胁迫的数字基因表达谱

基于高通量测序的数字基因表达谱(DGE)技术,对重金属污水胁迫处理组和对照组秋茄材料进行转录组测序分析。结果表明,重金属污水胁迫处理样品与对照样品相比,共筛选出的3 097个差异表达基因,其中2 202个表达上调,895个表达下调。GO功能显著性富集分析出38个GO分类条目,大量与生长发育,代谢调控,环境刺激响应相关的基因表现为富集。进一步的KEGG代谢途径分析表明,差异表达基因主要与糖类、核酸、蛋白质和脂质等生物大分子代谢、能量代谢以及次生代谢过程有关。转录因子分析发现b HLH,MYB,NAC和WRKY在重金属胁迫中发挥重要作用。此外,重金属胁迫还促进萜类、黄酮类化合物生物合成的关键酶基因(牻牛儿基焦磷酸合酶(Unigene0029352)、黄酮醇合成酶(Unigene0010384))的表达,进而促进秋茄有效成分的积累;显著诱导细胞分裂素相关基因type-b响应调节子ARR2(Unigene0033740)的表达、抑制油菜素内酯的信号转导组分基因BSK(Unigene0008986)的表达,进而提高秋茄对重金属胁迫的适应能力。实验选取了5个与环境刺激响应密切相关的基因,通过qRT-PCR验证了它们在重金属污水胁迫处理下的表达差异,结果与数字基因表达谱分析的结果较为一致,证实了差异表达基因数据的有效性。说明在重金属胁迫处理下,秋茄通过调节基因表达提高自身对污染胁迫的耐受能力。

不同浓度生活污水对秋茄(kanadelia candel)幼苗生长的影响

本文通过红树植物秋茄(kanadelia candel)幼苗在不同浓度生活污水中培养两个月,通过比较在不同浓度生活污水中秋茄幼苗生长的形态指标和生理指标差异,研究不同浓度生活污水对秋茄幼苗生长的影响。研究结果表明:不同浓度生活污水对秋茄幼苗的生长具有一定影响,低浓度的生活污水对秋茄幼苗的生长有促进作用,随着污水浓度增加这种促进作用加强,到中等浓度(40%左右)达到最大,而后随着生活污水浓度增加促进作用降低,最后出现抑制作用。本研究表明秋茄幼苗对生活污水的抗性较强,能耐受不同浓度生活污水的影响;同时表明红树植物对生活污水的适应能力较强,利用红树林湿地系统净化生活污水有一定可行性。试验结果为合理利用和保护红树林资源提供科学依据。

Effect of soil salinity on cold tolerance of mangrove Kandelia candel

Analysis of cold tolerance on mangrove Kandelia candel leaf growing in different soil salinity along Jiulong River Estuary in South China showed that the cold tolerance decreased as the increase of soil salinity. The lethal temperatures of K. candel leaf were -10.4, -9.9 and -8.6 ℃ in Liaodong, Baijiao and Aotou, respectively. Under 1–2℃ cold stress treatment on detached leaves of K. candel, their caloric value gradually decreased, while electrolyte leakage gradually increased. The leaf’s caloric value and electrolyte leakage in Aotou with higher soil salinity varied more largely than those in Liaodong with lower soil salinity. In K. candel leaf, total water content lowered a little, bound water content rose significantly and free water content dropped significantly with duration of cold stress. At the same time, reduction sugar, soluble sugar and starch content gradually decreased and sucrose content gradually increased. Bound water, free water and sucrose content in K. candel leaf from Aotou with higher soil salinity changed more slowly than those from Liaodong with lower soil salinity, but reduction sugar, soluble sugar and starch content in K. candel leaf from Aotou had faster variations than those from Liaodong. These data indicated that soil salinity can reduce cold tolerance of K. candel leaf by increasing negative effect of salt ions in cell membrane, inhibiting variations of water content, and aggravating consumption of material and energy.

PRELIMINARY STUDY ON MONTHLY CHANGES IN CALORIC VALUE OF Kandelia candel LEAVES IN JIULONGJIANG RIVER ESTUARY, FUJIAN

The measurement of caloric values is one of the most important ways in ecology research, which has seldom been carried out in our country. The mangrove serves as a primary producer in the aquatic food chain of the tropical estuary, and its leaves not only function as energy assimilation, but also take up the majority of litter. Therefore, to study the variations in energy content of the leaves of mangrove plants would be valuable for the researches of physiological ecology and the ecosystem.

Pattern changes and early risk warning of Spartina alterniflora invasion:a study of mangrove-dominated wetlands in northeastern Fujian,China

The exotic saltmarsh cordgrass,Spartina alterniflora(Loisel)Peterson&Saarela,is one of the important causes for the extensive destruction of mangroves in China due to its invasive nature.The species has rapidly spread wildly across coastal wetlands,challenging resource managers for control of its further spread.An investigation of S.alterniflora invasion and associated ecological risk is urgent in China's coastal wetlands.In this study,an ecological risk invasive index system was developed based on the Driving Force-Pressure-State-Impact-Response framework.Predictions were made of'warning degrees':zero warning and light,moderate,strong,and extreme warning,by developing a back propagation(BP)artificial neural network model for coastal wetlands in eastern Fujian Province.Our results suggest that S.alterniflora mainly has invaded Kandelia candel beaches and farmlands with clustered distributions.An early warning indicator system assessed the ecological risk of the invasion and showed a ladder-like distribution from high to low extending from the urban area in the central inland region with changes spread to adjacent areas.Areas of light warning and extreme warning accounted for43%and 7%,respectively,suggesting the BP neural network model is reliable prediction of the ecological risk of S.alterniflora invasion.The model predicts that distribution pattern of this invasive species will change little in the next 10 years.However,the invaded patches will become relatively more concentrated without warning predicted.We suggest that human factors such as land use activities may partially determine changes in warning degree.Our results emphasize that an early warning system for S.alterniflora invasion in China's eastern coastal wetlands is significant,and comprehensive control measures are needed,particularly for K.candel beach.

红树植物秋茄树叶挥发油化学组成特点的气相色谱/质谱分析

用水蒸汽蒸馏法提取出秋茄树Kandelia candel叶的挥发油,经气相色谱/质谱联机分析,分离出49个峰,鉴定出35种化合物,主要是2,6-二叔丁基-4-甲基苯酚、大根香叶烯-D、十七烷、石竹烯、十九烷、十五烷、贝壳杉-16-烯等,占总峰面积的93.77%。还讨论了上述挥发油化学组成的特点及主要组分的用途。

不同育苗基质对秋茄苗木生长的影响

了解不同育苗基质对秋茄苗木生长的影响,为生产上科学制定秋茄育苗的基肥提供理论参考。在广西英罗港口红树林苗圃内开展了不同育苗基质对秋茄苗木生长影响的试验,该试验设3个处理:A1的育苗基质为海泥搅拌30g复合肥(V复合肥∶V海泥=3∶500;VN∶VP∶VK=18∶12∶10),A2均为有机肥料,A3为底部11cm高的有机肥,表层11cm高的海泥,对照组的育苗基质均为海泥,研究育苗基质对秋茄发芽率、生长、生理的影响。试验结果表明:(1)育苗基质对秋茄苗木生长有影响,育苗基质均为有机肥料的秋茄发芽率为0,其它育苗基质的秋茄发芽率为100%;(2)育苗基质对秋茄地径无影响,对秋茄苗高有显著影响,A1处理的苗木最高,为53.70cm;(3)育苗基质对秋茄生理指标有显著影响,A1和A3处理的秋茄苗木营养元素均高于对照组。可见,在育苗基质中加入适量的肥料可促进秋茄苗木生长。

秋茄叶对复合重金属的胁迫反应及其积累能力研究

为了探究重金属胁迫对红树植物秋茄Kandelia candel(L.Druce)生理指标的影响,通过砂培试验研究了秋茄在5个不同级别(T0、T1、T2、T3和T4)的复合重金属(镉、铅和汞)处理30d后某些生理特性的变化。结果表明,随着复合重金属胁迫浓度的增加,秋茄叶片吸收重金属量增加,而叶绿素含量明显减少。抗坏血酸(AsA)含量在T3达到最大值,但在T4减少到对照水平。当重金属处理浓度大于T1时,谷胱甘肽(GSH)含量显著增加。秋茄叶抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)活性变化趋势与AsA活性变化相似,呈先升后降趋势,在T3时酶活性都达到最大值。重金属处理对谷胱甘肽过氧化物酶(GPX)活性有显著诱导作用。综合实验结果,可初步判断秋茄叶能积累和忍受一定量的重金属;为了减少重金属胁迫造成的氧化伤害,秋茄叶片通过调节体内的抗氧化剂含量和抗氧化酶活性来抵御活性氧的攻击。

不同浓度萘和芘处理对红树植物秋茄胚轴萌发和幼苗生长的影响

在实验室条件下,分别以0.1、1和10 mg/L三个浓度的萘和芘培养红树植物秋茄(Kandelia candel(L.)D ruce)幼苗,培养基盐度15,培养期60 d,以不加污染物培养为对照,分析了萘和芘对幼苗萌发和生长的影响.研究结果表明:低浓度萘和芘(0.1 mg/L)对秋茄胚轴萌发没有影响,对幼苗生长甚至有一定的刺激作用.高浓度处理(10 mg/L)则对胚轴第二对叶的展开有明显的抑制作用.高浓度萘处理的幼苗根、茎、叶及总量与对照组相比分别降低了95.2%、89.7%、85.5%和91.6%;高浓度芘处理则分别降低了50.4%,52.9%、73.9%和57.6%.在抑制程度上,萘处理明显大于芘处理.