滇苦菜（Picris divaricata Vant.）对锌的吸收和富集特性

A field survey and hydroponic culture were carried out to study the effect of zinc (Zn) on the growth and Zn accumulation of Picris divaricata Vant. Under natural conditions, total Zn concentration in soil from a Pb/Zn mine area ranged from 1724 to 134973 mg•kg^(-1), with a mean of 61495 mg•kg^(-1). Zn concentration in shoots of P. divaricata ranged from 1214 to 18339 mg•kg^(-1), with a mean of 5911 mg•kg^(-1) (DW). At the same time, the translocation factor (S/R) was larger than 1, with a mean value of 2.21. When exposed to Zn supply in solution, P. divaricata showed toxic symptoms at the 80 mg•L^(-1) Zn treatment. Zn concentrations in shoots and roots increased with increasing external Zn levels and reached maxima of 12472 and 14026 mg•kg^(-1), respectively, at Zn treatment of 160 mg•L^(-1). Zn accumulation also reached a maximum of 1518 μg•plant^(-1) at the 160 mg•L^(-1) Zn treatment, and 75%-91% of total Zn was accumulated in the shoots. We conclude that P. divaricata has great ability to tolerate, take up, and accumulate Zn, and that P. divaricata is identified as a new Zn hyperaccumulator native to China.