【作者】 张万旗；

【导师】 林思祖；

【作者基本信息】 福建农林大学 ， 林业， 2008， 硕士

【摘要】 针对目前红树林湿地重金属污染加重的现实及利用红树林湿地进行污水处理的设想,本文以红树植物秋茄(Kandelia candel L.Druce)为研究对象,通过温室砂培,模拟研究不同浓度镉(Cd)和氮(N)处理条件下,秋茄幼苗N、Cd累积分配变化规律及生长、生理响应。试验中N、Cd分别设四个浓度梯度:0mg/L、20mg/L、40mg/L、60mg/L;0mg/L、0.5mg/L、1.0mg/L、2.0mg/L。秋茄幼苗在不同浓度N、Cd处理条件下培养90d后,其植株Cd含量、N含量、叶绿素含量、膜保护酶活性及生物量等指标的变化表明:1.试验条件下,不同浓度N、Cd处理对秋茄幼苗不同器官中Cd含量的变化研究表明:秋茄幼苗根部Cd含量明显高于茎和叶,根部是吸收、累积Cd的主要器官。不同的Cd处理系列中,秋茄幼苗各器官中Cd的含量随着施N量的增加而增加;同样,在不同的N处理系列中,Cd处理浓度增加时,幼苗各器官中Cd含量亦随之增加。在同一Cd胁迫水平条件下,秋茄幼苗各器官对Cd的累积系数均表现为随施N量的增加而变大:在同一施N水平下,随着Cd处理水平的提高,秋茄幼苗叶片、茎对Cd的累积系数逐渐下降。2.试验条件下,不同浓度N、Cd处理对秋茄幼苗不同器官中N含量的分析研究表明:秋茄幼苗根、茎、叶中N含量随N施用量和Cd胁迫浓度的改变而改变,叶片N含量高于茎、根。在同一N水平条件下,Cd胁迫浓度的增加通常会导致幼苗各器官中N的含量减少;而在同一Cd胁迫浓度下,N施用量的增加则会使幼苗各器官N含量显著增加。3.试验条件下,不同浓度N、Cd处理对秋茄幼苗叶绿素影响的效应分析表明:同一Cd胁迫水平下,随着施N量的增加,秋茄幼苗叶绿素a(Chla)和叶绿素b(Chlb)含量均表现出增加的趋势,而在同一N水平处理下,叶绿素变化规律并不一致,随着Cd胁迫浓度的增大,秋茄幼苗叶绿素a(Chla)含量呈先增后减的抛物状变化趋势,在Cd浓度为0.5mg/L处理中达到其最大值;而叶绿素b(Chlb)含量随着Cd胁迫浓度的增大呈缓慢减少的趋势。4.试验中,不同浓度N、Cd处理秋茄幼苗叶片SOD活性的变化分析表明:不同的镉处理系列中,SOD活性随着氮处理浓度的提高而呈上升趋势,在不同氮水平处理间的SOD活性差异均达到极显著水平;在不同氮处理条件下,SOD活性则随着镉处理水平的提高也呈上升趋势,中镉(Cd 1.0mg/L)和高镉(Cd 2.0mg/L)条件下,秋茄幼苗叶片SOD活性与对照间的差异均达到极显著水平。5.试验条件下,不同浓度N、Cd处理对秋茄幼苗叶片POD活性效应分析的变化表明:在不同氮系列中,秋茄幼苗POD活性随着镉胁迫浓度的提高而呈上升趋势,并且在高镉(Cd2.0 mg/L)、中镉(Cd 1.0mg/L)、低镉(Cd 0.5mg/L)处理后,秋茄幼苗POD活性与对照间(Cd 0mg/L)的差异均达到极显著水平。不同的镉处理系列中,POD活性随着氮处理浓度的提高而呈下降趋势,在经镉胁迫条件下,经较高氮(≥40mg/L)处理,秋茄幼苗POD活性与对照(N0mg/L)间的差异达到极显著水平。6.在各个N处理系列中,秋茄幼苗叶片的MDA含量均随着Cd处理浓度的升高而增大;中(Cd 1.0 mg/L)、高(Cd 2.0 mg/L)浓度Cd处理间及与对照(Cd0mg/L)之间均存在极显著差异。在不同浓度镉处理条件下,幼苗叶片的MDA含量随着N处理浓度的增大而减少,在4个镉系列中,高氮及中氮处理条件下秋茄幼苗叶片的MDA含量与对照(N 0mg/L)之间均存在极显著差异。7.在同一N水平条件下,秋茄幼苗根、茎、叶的生物量随着Cd胁迫浓度的增加而改变;在大多数处理中,生物量均随着Cd胁迫浓度的增加而表现出降低的变化趋势。而在同一Cd胁迫浓度下,幼苗根、茎、叶的生物量均随着施N量的增加而显著增加。本研究可为Cd胁迫下的秋茄栽培以及利用红树植物秋茄进行污水处理提供理论依据。更多还原

【Abstract】 In view of the pollution of heavy mental in mangrove wetlands is aggravating and the assumptions of the utilization of mangrove in sewage treatment at present, Kandelia candel mangrove was regarded as the research object in the paper,cultivated in sand and treated with 10%o brine for 90 days in a greenhouse,by way of simulation test to study the accumulation and distribution of N and Cd and the effects on growth and physiology of the Kandelia candel under different concentrations of N and Cd treatments.There were 4 treatments of Cd including control(0 mg/L),low Cd(0.5 mg/L),medium middle Cd(lmg/L),high Cd(2mg/L);the 4 N treatments comprises control(0 mg/L),low N(0.5 mg/L),middle N(1 mg/L),high N(2mg/L).The influence of different concentrations of Cd and N treatments on Kandelia candel including Cd content and N content of different parts,chlorophyll content,antioxidase membrane protection system and the biomass of Kandelia candel were observed after 90 days’ stress of different concentrations of N and Cd treatments.The results were as follows:1.The experiment showed that the Cd content of roots was higher than that of stems and leaves,and roots of Kandelia candel were the main organ of cadmium absorption and accumulation.The Cd content of different parts showed a climb under different Cd treatment series when the N concentration increased;meanwhile,the Cd content of different parts were also promoted when the Cd concentration increased under different N treatments.The Cd accumulation coefficient of different parts of Kandelia candel was increased with the increase of N concentration under the same Cd treatment,while the Cd accumulation coefficient of different parts of KandeIia candel dropped when the Cd concentration increased under the same N treatment.2.The N content of the roots,stems and leaves varied with the Cd and N concentrations in the experiment;the N content of leaves was higher than that of stems and roots.Under the same N concentration,the increase of Cd stress concentration led to the reduction of N content of the different parts of Kandelia candel,while the N content of different parts climbed when the N treatment concentration increased.3.The contents of chlorophyll a and chlorophyll b of Kandelia candel were enhanced when the N concentration level increased under the same Cd treatment;while under the same N treatment,the variation of the chlorophyll contents were inconsistency: the content of chlorophyll a increased with the increase of Cd stress concentration and reached the max at the low Cd(0.5mg/L)treatment,then declined with the increase of Cd stress concentration;while the content of chlorophyll b were enhanced gradually with increasing Cd concentration.4.The experiment showed that SOD activity in leaves raised gradually with increasing of N treatment concentration under different Cd treatment series,and SOD activity had significant difference between different N treatments;under different N treatment series,SOD activity also raised with increasing of Cd treatment,SOD activity of Kandelia candel when treated under middle Cd(1 mg/L)and high Cd(2 mg/L)had significant difference contrasted with that of control(Cd 0 mg/L).5.The experiment showed that POD activity in leaves raised gradually with increasing of Cd treatment concentration under different N treatment series,and the POD activity of Kandelia candel when treated under high Cd(2 mg/L),middle Cd(1 mg/L)and low Cd(0.5 mg/L)had significant difference contrasted with that of control (Cd 0 rag/L).Under different Cd treatment series,POD activity in leaves declined with increasing of N treatment concentration,the POD activity of Kandelia candel when treated with higher N(≥40 mg/L)had significant difference contrasted with that of control(N 0 mg/L).6.Under different N treatment series,the MDA content of Kandelia candel leaves increased with increasing of Cd treatment concentration;there was significant difference between the MDA content of leaves treated by high Cd(2 mg/L),middle Cd(1 mg/L) and the control(0 mg/L)groups.Under different Cd treatments,the MDA content of leaves reduced when N concentration increased;there was significant difference between treatments of high N(60 mg/L),middle N(40 mg/L)and the control(0 mg/L) groups.7.The biomass of the roots,stems and leaves of Kandelia candel varied with the Cd concentrations in the same N group;in most of the treatments,the biomass reduced when the Cd concentration increased.While the biomass of roots,stems and leaves were significantly promoted when the N concentration increased under the same Cd treatment.This paper can provide theoretical basis for the cultivation of Kandelia candel under stress of Cd and the utilization of Kandelia candel mangrove in sewage treatment.更多还原