【作者】 韩玉林；

【导师】 夏冰；

【作者基本信息】 南京农业大学 ， 植物学， 2007， 博士

【摘要】 本文在以往对鸢尾属植物种质资源抗旱、耐水湿以及重金属镉（Cd）、铜（Cu）积累、耐性等综合评价研究的基础上,选用了黄菖蒲（Iris pseudacorus L.）、喜盐鸢尾（I.halophild Pall.）、花菖蒲（I.ensata vat.hortensis Makino et Nensoto）、马蔺（I.lactea var.chinensis（Fisch.）Koidz）,鸢尾（I.tectorum Maxim.）和蝴蝶花（I.japonica Thunb.）6种鸢尾属植物,通过水培、沙培、人工污染土壤盆栽以及污染土壤实地栽培等方法,对其植物铅（Pb）积累、耐性机理及盐（NaCl）、锌（Zn）影响,Pb和Cd在细胞超微结构中的分布和Pb污染土壤修复潜力进行了研究。初步研究结果如下:1、不同鸢尾属植物对Pb积累能力不同,供试6种鸢尾属植物中花菖蒲、喜盐鸢尾和马蔺对Pb的积累和耐受能力相对较强,其中在4 mmol·L^-1Pb浓度胁迫下,喜盐鸢尾、花菖蒲和马蔺3种鸢尾地上部的Pb含量均超过了1000μg·g^-1,分别为1103μg·g^-1、1008μg·g^-1和1109μg·g^-1,其地上部干重与对照没有显著差异,表明此胁迫浓度对上述3种植物的生长没有产生明显影响;在较高浓度Pb胁迫下,黄菖蒲对Pb的积累较好;而鸢尾和蝴蝶花对Pb的耐受和积累能力在所有处理浓度下都不如其他4种鸢尾属植物;在供试的6种鸢尾中,花菖蒲和马蔺在不同浓度Pb胁迫下均表现出相对较好的Pb吸收迁移能力。2、对喜盐鸢尾和黄菖蒲在不同Pb浓度、时间胁迫下植物的生理生化进行了研究,结果表明:在Pb胁迫下,2种鸢尾属植物叶绿素含量随Pb处理浓度的增加而降低,而且,随着时间的延长相同Pb处理下叶绿素的含量先降后升;相对Pb耐性植物喜盐鸢尾在4 mmol·L^-1低浓度Pb胁迫下,叶片內MDA含量在不同胁迫时间内与对照均无显著差别,而相对Pb敏感性植物黄菖蒲叶片的MDA水平明显高于对照,在相对高Pb浓度胁迫下黄菖蒲叶片的MDA上升幅度大于喜盐鸢尾;2种鸢尾的SOD活性和脯氨酸含量在Pb胁迫下均有不同程度增加。与黄菖蒲相比喜盐鸢尾表现出相对较强的胁迫诱导生理抗性能力。3、采用溶液培养研究了Pb、NaCl胁迫对喜盐鸢尾（Iris halophila Pall.）和黄菖蒲（I.pseudacorus L.）植物体內的Pb含量、植物生长及生理指标变化的影响。结果表明,Pb胁迫下NaCl的加入增加了2种鸢尾属植物根系对Pb的吸收和积累,并导致植物伤害MDA含量增加和鲜重下降;Pb、NaCl单独或复合胁迫均不同程度地增加了2种鸢尾属植物SOD酶活性和Pro含量,一定程度上提高了植物的胁迫诱导抗性;一定浓度的单NaCl胁迫可促进喜盐鸢尾的生长,并表现出相对于黄菖蒲更好的耐盐性。4、采用土壤盆栽栽培试验,研究土壤Pb、Zn复合胁迫对喜盐鸢尾和黄菖蒲部分元素吸收及生长的影响,结果表明,Pb、Zn复合胁迫增加了Pb、Zn、Mn、Cu 4种元素在2种鸢尾体內的积累。同时,土壤中10 mmol kg^-1pb和50 mmol kg^-1Zn高浓度复合胁迫下,使2种鸢尾属植物叶长、根长、叶数、根数等减少,生物量降低,其中黄菖蒲受到的伤害相对较大。相关性分析表明,2种鸢尾属植物的生长状况与体內Pb,Zn含量呈负相关,且与Zn含量的负相关性大于Pb含量,说明Pb、Zn复合胁迫下过量Zn对喜盐鸢尾和黄菖蒲植物生长的毒害相对较大。5、对黄菖蒲、马蔺和鸢尾3种鸢尾属植物Pb、Cd胁迫16d,根尖细胞结构中Pb、Cd沉积与分布的透射电镜超微观察发现:Pb和Cd主要沉积在3种鸢尾属植物根尖的成熟区细胞的细胞壁、细胞膜和导管內壁上,极少部分在原生质中;在液泡和细胞间隙中没有观察到Pb和Cd的沉积;3种鸢尾表现出在细胞超微结构中的区室化分布的不完全一致性。Pb主要沉积在黄菖蒲根尖的细胞壁表面,马蔺根尖细胞膜的表面;Cd主要沉积在黄菖蒲根尖细胞的细胞壁表面和细胞壁內,马蔺根尖细胞的细胞壁內以及鸢尾根尖导管內壁上和细胞壁內。6、采用铅污染土壤盆栽培养和实地栽培方法,对不同铅浓度土壤胁迫条件下黄菖蒲（Iris pseudacorus L.）、喜盐鸢尾（I.halophila Pall.）植物的生长、Pb吸收积累以及实际修复能力进行了研究评价。结果表明:Pb污染红壤实地栽培的黄菖蒲和喜盐鸢尾的地上部和地下部铅含量,分别为1117mg kg^-1、1982mg kg^-1和1273mg kg^-1、2698mg kg^-1,其含量均高于Pb污染的黄棕壤和红壤盆栽结果;2种鸢尾属植物在Pb污染红壤实地和红壤盆栽下其植物地上部Pb含量/地下部Pb含量（s/R）的比值均高于pH值高的的黄棕壤,说明酸性土壤有利于鸢尾属植物对铅的吸收和向地上部分迁移和运输;依据2种植物在Pb污染（红壤）实地栽培条件下果熟期地上部生物量（干重）的估算,对单位面积內污染土壤中Pb的年一次性提取量的评价,认为喜盐鸢尾和黄菖蒲对Pb污染土壤实际修复效果均有较好潜力。更多还原

【Abstract】 Based on the researches of drought and water-logged resistant and Cu,Cd accumulation and tolerance of the species of Iris L,the seedlings of 6 species of Iris L., Iris halophita Pall.,Ⅰ.pseudacorus L.,Ⅰ.ensata var.hortensis Makino et Nensoto,Ⅰ.lactea var.chinensis（Fisch.） Koidz,Ⅰ.tectorum Maxim.andⅠ.japonica Thunb.were planted in hydroponic system or artificial lead（Pb） polluted soil and Pb polluted soil to determine the effects of Pb,Pb+NaCl,Pb+Zn stress on the plant vigor,the Pb contents and distribution in different parts of the plants,physiological parameters and the sub-cellular localization of Pb and Cd and potential ability to remediate Pb contaminated soils.The results showed were as follow:1.The abilities of Pb accumulation were different among 6 species of Iris L.,Ⅰ. halophila Pall.,Ⅰ.pseudacorus L.,Ⅰ.ensata var.hortensis Makino et Nensoto,Ⅰ.lactea var. chinensis（Fisch.） Koidz,Ⅰ.tectorum Maxim.andⅠ.japonica Thunb.The contents of Pb in the shoots ofⅠ.halophila,Ⅰ.ensata var.hortensis andⅠ.lactea var.chinensis treated at 4 mmol·L^-1Pb were 1103μg·g^-1,1008μg·g^-1 and 1109μg·g^-1,respectively,exceeded 1000μg g^-1,the critical value of Pb hyperaccumulator,and the shoot dry masses were not significantly different with those of control.The Pb accumulation ofⅠ.pseudacorus was better in higher Pb level condition and those ofⅠ.tectorum,andⅠ.japonica were not good in all treatments.The Pb translating rates ofⅠ.ensata var.hortensis andⅠ.lactea var. chinensis in 4-6 mmol·L^-1Pb treatments were better than those of other species of Iris L.2.The seedlings ofⅠ.halophila andⅠ.pseudacorus were subjected in 0-10 mmol·L^-1 Pb and determined physiochemical parameters in different period.The results showed that the contents of chlorophylls in the leaves ofⅠ.halophila andⅠ.pseudacorus decreased as Pb concentrations were raised,and the contents of chlorophylls dropped and then slowly being raised at same Pb treatment as treatment period longer.The contents of MDA in the leaves ofⅠ.halophila which could accumulate higher content of Pb were not significantly different with those of control below 4 mmol·L^-1Pb treatments in the period of 7-28 days.However, the content of MDA in the leaves ofⅠ.pseudacorus was significantly different with that of control at 4 mmol·L^-1 Pb treatments in 28 days.The contents of proline and the activities of SOD in the leaves ofⅠ.halophila andⅠ.pseudacorus increased as the Pb concentrations were raised.The results indicated thatⅠ.halophila were higher tolerant species in the physiological characters than those ofⅠ.pseudacorus.3.The effects of Pb-NaCl interaction on the plant vigor,contents of Pb in the plant and physiological mechanisms ofⅠ.halophila andⅠ.pseudacorus were investigated in hydroponic system.The results showed that the contents of Pb in the plants of two species of Iris L.were increased under Pb+NaCl stress,while,the fresh weights were decreased as the concentrations of Pb+NaCl higher.The contents of malondialdehyde（MDA） were increased as the concentrations of Pb+NaCl rised.The activities of superoxide dismutases （SOD） and proline（pro） contents were significant increased as the concentrations of Pb,Na and Pb+NaCl enhanced,which might play key role to protect the plants from the stress of Na and Pb.The growth ofⅠ.halophila could be promoted by NaCl and the seedlings ofⅠ. halophila were more tolerant NaCl stress than those ofⅠ.pseudacorus.4.The study of Pb and Zn toxicity to the growth and Pb,Zn,Cu and Mn contents in the different parts of the seedlings ofⅠ.pseudacorus andⅠ.halophila in pot culture showed that the Pb、Zn、Mn、Cu contents in two species of Iris L.were increased under Pb and Zn stress.The normal growth and development of two species of Iris L.were damaged, numbers and lengths of leaves and roots,and biomasses of both species were decreased significantly due to the large amount of Pb、Zn、Mu、Cu in the plants treated with co-contamination of 10 mmol kg^-1Pb+50 mmol kg^-1Zn.The growths and developments ofⅠ. pseudacorus were effected more serious than those ofⅠ.halophila.The negative correlations were found between the growths and the contents of Pb and Zn ofⅠ. pseudacorus andⅠ.halophila.The negative correlations between the growth and the contents of Zn was much more obvious than between the growth and the contents of Pb in two species of Iris L.which indicated that Zn was more toxic than that of Pb to the seedlings ofⅠ.pseudacorus andⅠ.halophila.5.The studies on the sub-cellular localization of Pb and Cd in root cells ofⅠ. pseudacorus,Ⅰ.lactea var.chinensis andⅠ.tectorum which subjected to Pb and Cd by hydroponics and harvested after 16 days showed that Pb and Cd deposits were mainly found in the cell wall,along the plasma membrane,on the inner surface of some vessels and a very few in the cytoplasm of cells in the root tip cells.Pb and Cd deposits were not found in inter cellular space and vacuole of the cells.The compartmental distribution of Pb and Cd were different in the sub-cellular structure of 3 species of Iris L.Pb deposits were on the inner surface of died cell walls and Cd deposits on the inner surface of cell wall and in the cell walls ofⅠ.pseudacorus.Pb deposits were along the plasma membrane and Cd deposits in the cell walls and some organdies ofⅠ.lactea var.chinensis.Pb and Cd deposits were on the inner surface of some vessels or in some cell walls ofⅠ.tectorum.6.Seedlings ofⅠ.pseudacorus andⅠ.halophila were potted in yellow brown soil（CK）, yellow brown soil+10 mmol L^-1 Pb,polluted red soil and planted the seedlings on the slope where is near by the Pb smeltery.The dry weight（DW） of the shoots ofⅠ.pseudacorus,the DWs of the shoots and roots ofⅠ.halophila growing on the slope near by the Pb smeltery were significantly decreased compared with those of the CK（p＜0.05）.The contents of Pb in the shoots and roots ofⅠ.pseudacorus andⅠ.halophila growing on the slope near by the smeltery in Jiangxi province were 1117mg kg^-1、1982mg kg^-1and 1273mg kg^-1、2698mg kg^-1,respectively,higher than those of the plants potted in the yellow brown soil +10 mmol L^-1 Pb and polluted red soil.The values of Pb contents in the shoot/Pb contents in the roots （S/R）of the tested species of Iris L.growing in the red soil was higher than those growing in the yellow brown soil which indicated that the lower soils pH could promote the Pb accumulation and Pb translocation from roots to shoots of two species of Iris L.According to the estimated biomasses of two species of Iris L.in fruiting period and the Pb amounts removed from contaminated soils in unit area per year,Ⅰ.halophila andⅠ.pseudacorus have the potential ability to remediate Pb contaminated soils.更多还原