CAJ | 학술논문

通过盆栽试验,研究藿香蓟(Ageratum conyzoides)的地上部和地下部Cd含量、干重、转运系数、根冠比及叶片叶绿素荧光参数对不同梯度Cd胁迫的响应.结果表明：随 Cd胁迫浓度增加,藿香蓟转运系数逐渐降低,地上部和地下部Cd含量随Cd胁迫浓度的增加而逐渐升高,在 Cd(300 mg?kg-1)胁迫下,植株地上部Cd含量为125．50 mg?kg-1,这一结果已超过Cd超富集植物的临界值(100 mg?kg-1)；植株地上部及地下部干重随Cd胁迫浓度的增加均逐渐降低,且中、高浓度Cd胁迫对植物的生长具有显著的抑制作用,各处理间的根冠比呈上升趋势并比对照高,可见高浓度Cd胁迫可阻碍根系的生长,从而影响植物地上部对营养和水分的吸收,最终抑制植株生长及生物产量的提高；PSⅡ的最大光化学效率(Fv/Fm)、PSⅡ的潜在光化学效率(Fv/Fo)随着Cd胁迫浓度的增加均逐渐升高,初始荧光(Fo)和最大荧光(Fm)均逐渐降低,光量子产量(ФPSⅡ)、电子传递效率(ETR)、光化学猝灭系数(qP )及非光化学猝灭系数(qN )均出现先升后降的趋势；Cd胁迫扰乱叶片正常时期的光合特性及延缓植株衰老,但各处理间的叶绿素荧光动力学参数差异不显著,Cd胁迫对叶片PSⅡ反应中心的电子传递、光化学反应及散热能力影响较弱；高浓度 Cd胁迫明显抑制植株的生长,但植株地上部及地下部的Cd积累能力较强,可作为植物修复重金属污染土壤的备选植物并用来治理Cd污染的土壤.
통과분재시험,연구곽향계(Ageratum conyzoides)적지상부화지하부Cd함량、간중、전운계수、근관비급협편협록소형광삼수대불동제도Cd협박적향응.결과표명：수 Cd협박농도증가,곽향계전운계수축점강저,지상부화지하부Cd함량수Cd협박농도적증가이축점승고,재 Cd(300 mg?kg-1)협박하,식주지상부Cd함량위125．50 mg?kg-1,저일결과이초과Cd초부집식물적림계치(100 mg?kg-1)；식주지상부급지하부간중수Cd협박농도적증가균축점강저,차중、고농도Cd협박대식물적생장구유현저적억제작용,각처리간적근관비정상승추세병비대조고,가견고농도Cd협박가조애근계적생장,종이영향식물지상부대영양화수분적흡수,최종억제식주생장급생물산량적제고；PSⅡ적최대광화학효솔(Fv/Fm)、PSⅡ적잠재광화학효솔(Fv/Fo)수착Cd협박농도적증가균축점승고,초시형광(Fo)화최대형광(Fm)균축점강저,광양자산량(ФPSⅡ)、전자전체효솔(ETR)、광화학졸멸계수(qP )급비광화학졸멸계수(qN )균출현선승후강적추세；Cd협박우란협편정상시기적광합특성급연완식주쇠로,단각처리간적협록소형광동역학삼수차이불현저,Cd협박대협편PSⅡ반응중심적전자전체、광화학반응급산열능력영향교약；고농도 Cd협박명현억제식주적생장,단식주지상부급지하부적Cd적루능력교강,가작위식물수복중금속오염토양적비선식물병용래치리Cd오염적토양.
The pot experiments was conducted to investigate the above ground Cd content,below ground Cd content, transfer factor,above ground dry weight,below ground dry weight,ratio of root to shoot and chlorophyll fluorescence parameters response of Ageratum conyzoides to different concentrations of Cd stress.The results showed that the transfer factor of A.conyzoides decreased gradually with Cd concentration increasing.However,the above ground Cd contents and below ground Cd contents increased gradually with Cd concentration increasing.It reached 125.50 mg?kg-1 at the Cd concentrations stress which was 300 mg?kg-1 and the text result had exceeded the critical value of Cd hyperaccumulators which was 100 mg?kg-1 .The above ground dry weight and below ground dry weight in A.cony-zoides plant decreased gradually with Cd concentration increasing.The above ground dry weight and below ground weight would be inhibited significantly at the moderate Cd concentration stress and high Cd concentration stress.The ratios of root to shoot among different treatments increased gradually with Cd concentration increasing which were higher than the control.It followed that root system growth of A.conyzoides would be inhibited obviously at the high Cd concentration stress.Meanwhile the high Cd concentration stress had a negative impact on nutrient absorption and water uptake of the plant shoot.Ultimately the high Cd concentration stress inhibited the growth and yield increase of plant.With Cd concentration increasing,the maximal photochemical efficiency (Fv/Fm)and potential photochemical efficiency of PSⅡ(Fv/Fo)increased gradually,while both the initial fluorescence (Fo)and the maximum fluores-cence (Fm)decreased gradually,the quantum yield (ФPSⅡ),electron transfer efficiency (ETR),the photochemical quenching coefficient (qP)and non photochemical quenching coefficient (qN)increased firstly and then decreased.It was thus clear that,Cd stress disrupted photosynthetic characteristics of A.conyzoides leaves in normal times and de-layed senescence in plants.But fluorescence induction kinetic parameters among different treatments had no significant differences.Cd stress had less impact on electron transport,photochemical reactions and heat dissipation a-bility in the leaves of A.conyzoides.In the research,the growth and dry weight would be inhibited obviously at the high Cd concentrations stress,however,the above ground Cd content and below ground Cd content in A.conyzoides plant has had strong Cd accumulation capacity.Consequently,A.conyzoides could be served as an alternative plant for the phytoremediation which could be used to help repairng Cd contaminated soil.