Growth Effects of Pb stress on Seedling of <i>Lactuca sativa</i> L. and <i>Brassica campestris</i> L.ssp

Abstract

In order to understand the effects of lead on the growth of Lactuca sativa L. and Brassica Campestris L. ssp, the change of growth index of seedling was studied under lead stress (different concentrations of lead nitrate solution), and by soilless cultivation of seedlings in pots and in greenhouse. The results showed that two kinds of plant growth were affected by lead stress of different level, the growth speed of seedlings reduced but a great number of growth index were increased, in addition to fresh weight and dry weight of stem and leaf. The leaf number, leaf area, plant height and the fresh weight, dry weight of stem and leaf in Lactuca sativa L. were declined obviously, and the fresh weight, dry weight of roots were increased under higher levels of lead treatment at the same time. The each growth index of Brassica Campestris L.ssp was decreased in higher concentration of lead treatment. The growth of Lactuca sativa L. was slightly better and Brassica Campestris L. was slightly lower than control under 0.005 mg/L lead treatment. So, Lactuca sativa L. wasmore sensitive in low concentrations of lead than Brassica Campestris L. Both of them reduced their growth significantly, especially Brassica Campestris L.in 0.015 mg/L lead treatment. Each grow index of Lactuca sativa L.and Brassica Campestris L. changed most in all kinds of lead concentration, and the growth was inhibited most in 0.045 mg/L lead. The growth of Brassica Campestris L.was decreased more under higher concentrations of lead compared with Lactuca sativa L..