土壤覆盖耐性植物秸秆对树番茄幼苗生长及镉积累的影响

Effects of Mulching with Tolerant Plant Straw at Soil Surface on Growth and Cadmium Accumulation of Cyphomandra betacea

通过盆栽试验,研究了在镉污染条件下,土壤覆盖镉耐性植物(马唐、邻近风轮菜、车前、扬子毛茛)秸秆对树番茄幼苗生长及镉积累的影响。结果表明:与未覆盖相比,土壤覆盖四种耐性植物秸秆均提高了树番茄根系、茎杆、叶片、地上部分及整株生物量,也提高了树番茄光合色素含量和抗氧化酶(SOD、POD、CAT)活性。土壤覆盖马唐、邻近风轮菜和扬子毛茛秸秆提高了树番茄地上部分的镉含量,分别比未覆盖提高了80.74%、58.09%和28.31%,只有土壤覆盖车前秸秆的树番茄地上部分镉含量低于未覆盖(较未覆盖降低了12.25%)。此外,土壤覆盖马唐、邻近风轮菜和扬子毛茛秸秆提高了树番茄的镉转运系数,但车前秸秆降低了其转运系数。因此,土壤覆盖车前秸秆能够促进树番茄幼苗的生长,降低其地上部分镉含量,有利于镉污染果园中树番茄的正常生长及安全生产。

A pot experiment was conducted to study the effects of mulching with cadmium ＇ （Cd） tolerant plant species （Digitaria s anguinalis , ~antago asiatica, Clinopodium confine and Ranunculus sieboldii） straws at soil surface on the growth and Cd accumulation of Cyphomandra betacea under Cd contamination. The results showed that mulching with four tolerant plant species straws increased the biomass of root, stem, leave, shoot and the whole plant compared with control, and also improved the photosynthetic pigment content and antioxidant enzyme （SOD, POD, CAT） activity. Mulching with straws of D. sanguinalis, C. confine and R. sieboldii increased Cd content in shoot of C. betacea, respectively, by 80.74%, 58.09% and 28.31% compared with control. Only mulching with straw of P. asiatica decreased Cd content in shoot of C. betacea by 12.25% compared with control. Additionally, mulching with straws of D. sanguinalis, C. confine and R. sieboldii improved Cd translocation factor （TF） of C. betacea, and mulching with straw of P. asiatica reduced that compared with the control. Therefore, mulching with straw of P. asiatica could promote the growth of C. betacea seedling, and decreased Cd content in shoot of C. betacea seedling, which would be benefit to growth and safe production of C. betacea in Cd- contaminated orchard.