金丝草对Pb的富集效果及其体内Pb的存在形态

以Pb超富集植物——金丝草为材料,采用室内模拟胁迫土培试验,设计6种Pb胁迫浓度（150、250、500、1000、1500和2500 mg·kg-1）,同时设置未加Pb的对照,定量测定不同浓度Pb胁迫下金丝草根系和地上部分的生物量、Pb含量及存在形态,研究金丝草对Pb的富集效果及其体内Pb的存在形态和分布特征.结果表明：Pb胁迫对金丝草的生物量有一定的抑制作用,但在高浓度Pb的胁迫下,金丝草仍保持较大的生物量;金丝草对Pb有较强的耐性和富集能力,可将大量土壤中的Pb转移至地上部分,在Pb浓度为2500 mg·kg-1时,达到Pb超富集植物的标准;金丝草根系和地上部分的Pb主要以有机酸盐、蛋白质结合态等化合态为主,迁移能力降低,从而减小Pb胁迫对自身的伤害.

Accumulation effect,Pb existence form and distribution characteristics in Pogonatherum crinitum under Pb stress

In order to explore the tolerance and accumulation effect of Pb hyperaccumulator,the Pb hyperaccumulator Pogonatherum crinitum,which was first found by our research group was chosen and a simulation Pb stress test in controlled glasshouse was conducted.There were 6 ueatments （150,250,500,1000,1500 and 2500 mg · kg-1） with5 replicates.Biomass of shoot and root,Pb content,Pb form and distribution characteristics were measured.The accumulation effect to Pb and Pb existence form and disribution characteristics in P.cdnitum was analyzed.The results showed that,Pb stress had certain inhibition to biomass of P.criniturn,but kept relatively high biomass under high Pb stress conditon.P.crinitun had strong tolerance and accumulation capacity to Pb stress,and could transport more Pb to shoot from soil.Transfer coefficient and Pb concentration in shoot of P.crinitum reached the standard of Pb hyperaccumulation under Pb concentrarion 2500 mg· kg-1.The existence forms of Pb in P.crinitum mainly were organic acid salt and proteins combination which could decline the transformation of Pb in body,reduce the harm to plant.