两株耐铅镉真菌对土壤中铅镉赋存形态及小白菜吸收积累的影响

Effect of two lead-cadmium tolerant fungi on the fractionation of lead and cadmium in soil,and the accumulation of lead and cadmium in Chinese cabbage

通过土培试验,研究接种耐铅镉真菌(产黄头孢霉Cephalosporium chrysogenum和头孢霉Cephalosporium SP.)对灭菌和未灭菌铅镉污染土壤上小白菜生长及铅镉赋存形态的影响.试验结果表明:接种两种耐重金属真菌可以降低或显著降低土壤中交换态铅镉、碳酸盐结合态铅镉和铁锰结合态铅镉,且显著增加土壤中有机结合态铅镉,因此降低了土壤中铅镉的活性;在灭菌和未灭菌铅镉污染土壤上接种两种真菌均能增加或显著增加小白菜的株高和鲜重,其中在未灭土壤中接种产黄头孢霉20 mL小白菜鲜重和株高最大,分别达到6.00 cm和3.22 g·株^(-1),在灭菌土壤上接种产黄头胞霉10 m L小白菜株高和鲜重最大,分别为10.66 cm和11.07 g·株^(-1);接种两种真菌可以显著降低未灭菌土壤上小白菜体内铅镉含量和累积量,在灭菌土壤上接种10 mL产黄头孢霉可以显著降低小白菜铅含量和累积量.

Two fungi strains（ Cephalosporium chrysogenum（ CC） Cephalosporium sp.（ SP）） tolerant to lead（ Pb） and cadmium（ Cd） were inoculated in these two kind of heavy metals polluted soils to investigate the effect of fungi on Pb,Cd fractionation in soil and accumulation in Chinese cabbage. The result show that the exchangeable,carbonate bounded and Fe-Mn oxides bounded heavy metals in soils decreased with inoculation of fungi,but the concentration of heavy metals combined with organic significantly increased,which indicate that fungi decreased the bioavailability of Pb and Cd in soil.The height and fresh weight of cabbage was increased in both sterilized and non-sterilized soils with inoculation of fungi,and the height and fresh weight reached maximum in non-sterilized soil with inoculation of 20 mL CC and in sterilized soil with inoculation of 10 mL CC. The contents and accumulation of both heavy metals in cabbage decreased significantly with inoculation of fungi in non-sterilized soil,and Pb content and accumulation in cabbage also decreased in sterilized soil with inoculation of 10 mL CC.