Notice of Retraction: Foliar Trichome and Atmospheric Heavy Metal Accumulation of Seven Epiphytic Tillandsia Species

Abstract

Epiphytic Tillandsia plants, with non-absorptive roots and leaves densely covered with water-absorbing trichomes, have been widely used in biomonitoring studies of air pollution. Here we compared the foliar structure and bioindicating capacity of seven Tillandsia species. All the foliar trichomes of Tillandsia species were made up of disc cells, ring cells and wing cells. Atmospheric heavy metals Pb, Cu and Zn could be effectively measured by all seven Tillandsia species. Correlation analysis showed that trichome size was not significantly correlated with concentrations of Pb, Cu and Zn, but trichome density significantly correlated with concentrations of heavy metals. The results suggested that trichome density had a greater effect upon the ability of the epiphytic Tillandsia leaves on the accumulation of the atmospheric heavy meatals than trichome size.