Abstract

Nama aff. stenophylla plants grow on mining waste abandoned 100 years ago, exposed to high concentrations of heavy metals. Accumulation of heavy metals in plant biomass has been related to the phyto-accessible fractions of these, so we assessed the effect of those heavy metals in different concentrations on the germination and development of seedlings. The seed traits were characterized with optical and scanning electron microscope. The seeds were assessed for dormancy by pre-germinative treatments, germination percentage, tolerance index regarding heavy metals, and the elongation of seedlings under three concentrations of arsenic (As), cadmium (Cd), Iron (Fe), lead (Pb), and zinc (Zn) (phyto-accessible [Ph], five times higher [Hi] and lower [Lo]). The seeds have no dormancy, and the heavy metals did not affect the embryo. Pb, Cd, and As, affected the germination percentage more (p < 0.005). The treatments that most affected seedling elongation were Zn [Hi], Cd [Hi], Pb [Lo], Zn [Ph], Pb [Hi], Zn [Lo] (p < 0.005). The seedlings cells alterations were associated with the reduction in length, although larger cortical cells may be due to heavy metal compartmentalization in vacuoles. The seeds and seedlings showed tolerance to high concentrations of Fe and As, and to phyto-accessible of As, Cd, Pb, and Fe.

摘要

那抹AFF。甜叶菊植物生长于100年前废弃的采矿废物中，这些废物暴露于高浓度的重金属中。植物生物质中重金属的积累与植物中可利用的部分有关，因此我们评估了不同浓度的重金属对幼苗发芽和发育的影响。用光学和扫描电子显微镜对种子性状进行鉴定。通过发芽前处理，发芽率，重金属耐受性指数以及砷（As），镉（Cd），铁（Fe），铅（Pb），和锌（Zn）（植物可吸收的[Ph]，[Hi]的高五倍，[Lo]的低五倍）。种子没有休眠，重金属也没有影响胚胎。铅，镉和砷p  <0.005）。对幼苗伸长率影响最大的处理是Zn [Hi]，Cd [Hi]，Pb [Lo]，Zn [Ph]，Pb [Hi]，Zn [Lo]（p  <0.005）。幼苗细胞的变化与长度的减少有关，尽管较大的皮层细胞可能是由于重金属在液泡中的分隔。种子和幼苗显示出对高浓度的铁和砷的耐受性，以及对砷，镉，铅和铁的植物可吸收性。