The Study On Tolerance, Physiological Metabolism In Kenaf(Hibiscus Cannabinus L.) Under The Stress Of Pb And Cd

In this study the experimental materials that cytoplasmic male-sterility(CMS) lines P3A, Restorer Lines992and their hybridization F1of Kenaf were treated with single and combined Pb and Cd in different concentrations through germination and pot planted. The responses of seed germination and plant growth, physiological and biochemical characteristics, Pb and Cd content of kenaf undert the single and combined of Pb and Cd were investigated.The main results showed that as follows:1. Seed germination experiments showed that:The germination energy, germination rate, index of germinnation, index of vigor, simplified index of vigor among three materials showed a decreasing trend under the effect of single and combined of Pb and Cd; The germination energy of P3A and the germination rate of992have picked the phenomenon of volatility at Cd30mg/kg; Among the three materials, F1recorded best germinate, while P3A showed the worst; Under the high Pb and Cd concentration, short stems and no lateral, the red dot in the bud tip and bud root of kenaf seedling, and then decay gradually.2. The experiments of kenaf growth showed that:Pb and Cd stress significantly inhibited the growth of kenaf seedlings, caused the decline in the part of agronomic traits, dry mass of lead and stem, root dry mass, ratio of root to shootof kenaf; Root length, root surface area, root tips of kenaf were decreased with the increasing concentration; Root volume, average diameter increased with increasing concentration under the low consistence, but were decreased obviously under the high consistence; Responses to Pb and Cd were different among different genotypes, F1showed both strong heterosis and heterobeltiosis, P3A performance of the worst; The effects of Pb, Cd on kenaf rentended Pb+Cd> Cd>Pb.3. The physiological and biochemical experiments showed that:Chlorophyll content, MDA content and proline content among different genotypes of three materials under the stress of Pb, Cd single and combined were positively correlated with the processing concentration; Soluble protein content was negatively correlated with the concentration of treatment; The soluble carbohydrate contents of three varieties of kenaf went up at first and down afterward of single stree Pb and Cd, and yet it always went up of combined treatment; The SOD activity of three meterials were promoted undert the low single and combined concentration of Pb and Cd, yet under the high concentrations showed a strong inhibition; The effects of POD activity in three materials showed went up at first and down afterward under the low concentration of Pb, but at low concentration on single Cd amd combined treatment showed significant inhibition; The number of physiological indicators of P3A changed significantly, F1was not obvious.4. The enrichment of kenaf experiment showed that:The accumulation of Pb,Cd of three materials in aboverground and root increased with the increasing of treatment concerntion; The accumulation of Pb was decreasing with the increasing of Cd treatment in combined treatment, the accumulation of Cd was contrary; The bioconcentration foctor and translocation of three materials were less than1, it was not the hyperaccumulator, but the accumulation of Pb and Cd in F1was more than P3A and992.