Department of Botany, Sri Venkateswara University, Tirupati-517502
** Present Address: Plant Science Laboratories, Department of Bio-Sciences, Sri Krishnadevaraya University, Anantapur-515003.
* A part of the Ph.D. thesis approved by Sri Venkateswara University, Tirupati.
Studies of heavy metal tolerance of weed species revealed that the plant species differ in their metal contents although they are growing on the same soil. Plants, which showed high degree of tolerance, have accumulated low concentrations of metals in leaves. In Ocimum basilicum stem/leaf metal ratios for Co or Ni-treated plants are below 1, while for Cu or Zn-treated plants they are above 1. Leaf metal levels were not correlated to the total plant metal content. Deciduous leaves of Cu-tolerant plants showed high concentrations of copper.
