Abstract:

In this study, a pot experiment was carried out using three kinds of legume species (Pisu sativum L., Glycinemax (L.) merr. and Phaseolus vulgaris L.) as test objects and six different Pb concentrations (0, 100, 500, 1000, 2000, 3000 mg/kg) were added to the soil, which were conducted to study the differences of physiological indices of three crops. The results showed that, there was a promotion effect on the content of total chlorophyll and chlorophyll a in three species under low concentration of Pb (below 100 mg/kg). The high-concentration (2000 mg/kg and 3000 mg/kg) presented the inhibitory effect on both the content of total chlorophyll and chlorophyll a in Glycinemax (L.) merr. and the content of chlorophyll a in Pisu sativum L., while presented no significant effect on both the content of total chlorophyll and chlorophyll a in Phaseolus vulgaris L. and the content of total chlorophyll in Pisu sativum L.. There was a promotion effect on the content of chlorophyll b in Phaseolus vulgaris L. under the concentration of Pb (100-3000 mg/kg). A certain concentrations of Pb (1000 mg/kg and 100 mg/kg) had a promotion effect on the content of chlorophyll b in Pisu sativum L. and Glycinemax (L.) merr.. When lead content was 100-3000 mg/kg in soil, there was no significant change in the value of chlorophyll a/b of Glycinemax (L.) merr.. There was significantly positive association between the content of proline in three species and lead content in soil at 0.001 levels. The accumulation of proline was the highest in Glycinemax (L.) merr. and the lowest in Phaseolus vulgaris L. with the increase of Pb concentrations. The contents of total chlorophyll, chlorophyll a and chlorophyll b showed significant differences (P<0.05) among three species under six Pb treatments.