Response of different Hibiscus mutabilis L.varieties to cadmium stress
In order to understand the response of different Hibiscus mutabilis L.varieties to cadmium(Cd)stress,the hydroponic experiments were conducted to investigate the growth,tolerance,leaf pigment,Cadmium(Cd)concentration,Cd accumulation,bioconcentration factor and transfer factor of four different Hibiscus mutabilis L.varieties under different Cd concentrations(0,2.5,5,10 mg·L-1).The results showed that with the increase of Cd concentration,the growth of Hibiscus mutabilis L.showed a toxic hormetic effects.Basically,compared with CK(0 mg·L-1),adding Cd(treatments)increased biomass,root length and new branch length for all Hibiscus mutabilis L.varieties under low Cd concentration,but had opposite effects under high Cd concentration.Under Cd treatment,the leaf pigment concentration of all varieties were significantly lower compared with CK,and the leaf pigment concentration of'Bairihuacai'species was the highest.The Cd tolerance index of Hibiscus mutabilis L.was 0.76-1.17,and'Bairihuacai'species had the highest Cd tolerance index(1.00～1.17).The Cd concentration in the root of Hibiscus mutabilis L.(205.01～1089.35 mg·kg-1)was significantly higher than that in shoot(27.70～188.92 mg·kg-1).The Cd concentration in the root of'Bairihuacai'species was the highest than others,and'Caixia'species had the highest Cd concentration in the aboveground part.Cd accumulation in the aboveground part of Hibiscus mutabilis L.was significantly higher than that in the root,which was 0.17～1.01 mg·plant-1 and 0.04～0.32 mg·plant-1 respectively.The enrichment coefficient of Cd in Hibiscus mutabilis L.was 56.83-115.59,and the transport coefficient was from 0.08 to 0.38.Among which'Bairihuacai'species had the highest Cd enrichment ability,and'Caixia'species had the highest Cd transport coefficient.In conclusion,Hibiscus mutabilis L.has strong tolerance and accumulation ability under Cd pollution condition,among which'Bairihuacai'species had the best tolerance and the strongest Cd accumulation ability among the four species,and had the greatest potential as an ornamental emediation plants for Cd restoration.
万方数据
维普
