中文摘要：

为阐明紫金牛属植物在镉胁迫下的生理响应,比较2种紫金牛属植物抗逆性强弱,通过水培试验,研究了不同浓度镉（0,0.025,0.05,0.1,0.2,0.4mol/L）对2a生扦插苗虎舌红和朱砂根株高、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、过氧化氢酶（CAT）活性、脯氨酸（Pro）、叶片丙二醛（MDA）含量、光合特性及荧光特性等生理指标的影响。结果表明：（1）镉胁迫处理后,朱砂根和虎舌红的株高、SOD、POD以及CAT活性均有不同程度的上升,但随着处理时间的延长,株高以及抗氧化酶活性均显著降低;（2）低浓度镉（≤0.025mol/L）在处理时间≥20d时,可明显诱导2种植物Pro的积累,其中虎舌红增幅显著,达149.21%;（3）在处理时间≥20d时MDA含量增加,最高上升169.07%和122.70%;（4）低浓度镉（≤0.025mol/L）处理下虎舌红光合电子转移效率（ETR）上升较为明显,qP则无显著变化,高浓度Cd（≥0.2mol/L）处理后虎舌红ETR显著降低,qP也大幅下降。朱砂根的ETR荧光参数在处理前期就呈现下降趋势,且后期下降幅度增大。综合分析认为,较低浓度镉处理下朱砂根和虎舌红均可经过提升各种抗氧化酶活性的措施来抵御逆境,而高浓度镉则会对植物抗氧化酶系统、光合系统等造成损害。通过比较虎舌红与朱砂根抗镉性强弱,发现前者抗逆性更强,在较高的镉浓度环境中具有较为突出的种植优势。

英文摘要：

To clarify the physiological responses and compare the resistance intensities of two Ardisias pecies to the treatments of cadmium stress,hydroponic experiment was carried out with 2 years old seedlings of Ardisia crenata Sims. and Ardisia mamillata Hance.In the experiment,the cadmium concentrations were designed as 0,0.025,0.05,0.1,0.2, and 0.4 mmol/L.Several physiological indicators including plant height,superoxide dismutase（SOD）,peroxidase（POD）, and catalase（CAT）activities,proline（Pro）,content malondialdehvde（MDA）content,photosynthetic characteristics, and fluorescence characteristics were measured.The following results were obtained：（1）Plant height,SOD,POD, and CAT activities of A.crenata and A.mamillata first increased with the increase of incubation time, and then the first two indicators decreased significantly;（2）After 20 days treatment,the accumulation of Pro content in the two plant species was induced for low cadmium concentration treatment（T2）,especially significant for A.ma-millata,which was up to 149.24% ;（3）After 20 days treatment,MDA contents increased,with the highest increases of 169.07% and 122.70% ,respectively;（4）An obvious increase of photosynthetic electron transfer efficiency（ETR）of A.mamillata was observed for low cadmium concentration treatment（T2）,while qP（photochemical quenching coefficient）had no significant change,indicating that A.crenata startes the energy dissipation pathways sufficiently to avoid the damage of photosynthetic mechanism;（5）Both ETR and qPof A.mamillatadecreased significantly after treatment with high concentration of cadmium（T4）,indicating that PSII of A.mamillata has been hurt under the high concentrations of cadmium stress with the increasing of SOD and the damage of chloroplast structure;（6）ETR fluorescence parameters of A.crenata descended even in early stage of cadmium stress, and the decrease was much more significant in the later stage.After comprehensive analyses,it is supposed that both A.cr