锑砷复合胁迫对地枇杷生理变化及锑砷吸收分布的影响

Physiological Response and Arsenic or Antimony Absorption/Distribution of Ficus tikoua Under Arsenic and Antimony Combined Stress

通过砂培盆栽的方式,运用单因子方差分析及多重比较、样本t检验的统计方法,探讨不同浓度的锑胁迫(0、5、10、20、40、80和100μmol/L)和锑砷复合胁迫(0+10、5+10、10+10、20+10、40+10、80+10和100+10μmol/L)对地枇杷生物量、叶绿素含量、叶绿素荧光参数等生理生化指标的影响。结果表明:(1)地枇杷是一种典型的锑耐受性植物,植株体内的锑主要累积在根部;当单一胁迫锑浓度不超过100μmol/L时,锑对地枇杷的叶绿素含量、光合作用活性影响不大,但地枇杷的干物质累积受到一定的限制;(2)锑砷复合胁迫下,地枇杷根中锑和砷的吸收累积互为促进作用,而茎和叶中砷锑的转移、存储互为抑制作用;(3)虽然锑砷复合胁迫会降低地枇杷的干重,但低浓度(5~20μmol/L)的锑会减轻砷对叶绿体的毒性,而高浓度(40~100μmol/L)锑会加剧砷对叶绿体的毒性,造成地枇杷光合作用系统的不可逆损伤,使光合作用活性和能力降低;(4)砷对地枇杷的毒害作用明显比锑强,砷的加入会抑制地枇杷叶干物质积累,而且砷和高浓度锑复合胁迫会降低地枇杷茎的干物质累积。

In our potted sand culture experiment,the simple factor analysis of variance,methods of multiple comparisons and independent exponent t-test were used to analyze the influence of antimony(Sb)solo stress(0,5,10,20,40,80 and 100μmol/L),and antimony and arsenic(AS)combined stress(0+10,5+10,10+10,20+10,40+10,80+10 and 100+10μmol/L)on the physiological change of Ficus tikoua,including biomass,chlorophyll content and chlorophyll fluorescence parameters.The results showed that:(1)F.tikoua was a typical Sb tolerant plant,and the majority of Sb accumulated in the roots;when the level of Sb solo stress was≤100μmol/L,the SPAD value and chlorophyll fluorescence parameters were little affect by Sb addition,but the accumulation of dry matter was inhibited to a certain extend;(2)Under the combined stress of Sb and As,the uptake and accumulation of Sb and As by the roots were mutually reinforcing,while the transfer and accumulation of As and Sb in the leaves and stems were mutually inhibited;(3)Although the combined stress of Sb and As caused the dry matter weight to decrease,the low level of Sb(5-20μmol/L)would alleviate As toxicity to the chloroplasts,the high level of Sb(40-100μmol/L)would aggravate As toxicity to the chloroplasts,causing irreversible damage to the photosynthesis system and the reduction of the photosynthesis ability and activity;(4)As possessed a stronger toxicity to F.tikoua than Sb,the addition of As would inhibit the accumulation of dry matter in the leaves,and the combined stress of As and high levels of Sb would inhibit the accumulation of dry matter in the stems.