摘要
【目的】探讨重金属汞(Hg)对茅苍术光合特性及生理指标的影响,明确茅苍术叶片承受汞胁迫的阈值,为茅苍术无公害栽培提供理论参考。【方法】采用盆栽法对茅苍术开展不同浓度(0、10、20和50 mg/kg)的汞胁迫试验,分别在胁迫后0、7、14、21、28和35 d测定茅苍术叶片的光合特性及生理指标。【结果】在不同浓度汞胁迫处理下,随着胁迫时间的延长,茅苍术植株的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间二氧化碳浓度(Ci)整体上呈先增大后减小的变化趋势,至胁迫后期时茅苍术的光合能力明显下降。经不同浓度的汞胁迫处理后,茅苍术叶片的超氧化物歧化酶(SOD)活性变化不明显,而过氧化物酶(POD)活性和丙二醛(MDA)含量整体上呈先上升后下降的变化趋势,在胁迫后第28 d达最大值;过氧化氢酶(CAT)活性整体上呈上升趋势(50 mg/kg浓度除外);至胁迫后第35 d,均以10 mg/kg浓度处理的POD、SOD和CAT活性最高。茅苍术叶片的MDA含量在不同浓度汞胁迫处理下整体上呈先上升后下降的变化趋势,相对电导率则呈缓慢上升趋势。【结论】当汞胁迫浓度超过10 mg/kg时会抑制茅苍术叶片的光合能力,使其生理功能受到损害。
【Objective】The influence of heavy metal mercury(Hg)on photosynthesis characteristics and physiological indexes of Atracty lodeslancea(Thunb.)DC.was investigated and threshold of A.lancea leaves under mercury stress was studied to provide theoretical basis for pollution-free cultivation of A.lancea.【Method】Mercury stress of different concentrations(0,10,20 and 50 mg/kg)on A.lancea was conducted by pot experiment.The photosynthetic characteristics and physiological indexes of A.lancea leaves were determined 0,7,14,21,28 and 35 d after stress.【Result】Under mercury stress of different concentrations,net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs)and intercellular carbon dioxide concentration(Ci)of A.lancea seedlings went through a up-down variation in general as stress time prolonged,at stress late period,photosynthetic capacity of A.lancea dropped greatly.After mercury stress of different concentrations,activity of superoxide dismutase(SOD)in A.lancea leaves did not change greatly,but peroxidase(POD)and content of malondialdehyde(MDA)increased first and then decreased in general,and reached the peak on day 28 after stress.Catalase(CAT)activity increased in general(except for stress under 50 mg/kg concentration).After 35 d of mercury stress,A.lancea treated by 10 mg/kg concentration had the highest POD,SOD and CAT activities.MDA content in the leaves went through an up-down change under mercury stress of various concentrations in general,but relative conductivities showed a linear upward trend.【Conclusion】When the mercury stress concentration is higher than 10 mg/kg,photosynthetic capacity of A.lancealeaves would be inhibited,which will damage its physiological functions.
作者
孙永娣
巢建国
谷巍
王马勃
张文明
SUN Yong-di;CHAO Jian-guo;GU Wei;WANG Ma-bo;ZHANG Wen-ming(College of Pharmacy,Nanjing University of Chinese Medicine,Nanjing 210023,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2018年第3期448-453,共6页
Journal of Southern Agriculture
基金
国家自然科学基金项目(81573520)
国家基本药物所需中药材种子种苗繁育基地建设项目(2014-茅苍术)
国家水生
耐盐中药资源的合理利用研究行业专项项目(201407002)
江苏省"六大人才高峰"高层次人才项目(2012-YY-009)
关键词
茅苍术
汞胁迫
光合特性
生理指标
Atracty lodeslancea(Thunb.)DC.
mercury stress
photosynthesis characteristic
physiological index
