丛枝菌根真菌和两株细菌对土壤中DEHP降解及绿豆生长的影响

Influence of an arbuscular mycorrhizal fungi and two bacterial strains on DEHP degradation and growth of mung bean in soil

采用绿豆为供试植物,通过温室盆栽试验研究接种丛枝菌根(arbuscular mycorrhiza,AM)真菌与DEHP降解菌对DEHP污染土壤的修复作用以及对植物生长的影响.试验土壤中添加DEHP含量为100mg.kg-1,试验设AM真菌Acaulospor alaevis90034、降解菌Bacillussp.DW1和Gordoniasp.DH3单独接种以及互相组合的联合接种处理,同时设置不接种的对照处理(CK).苗后60d收获植株.结果表明,AM真菌能很好的侵染绿豆的根系,菌根侵染提高了绿豆地上部分的干重,而对根系的干重则没有显著的影响;同时菌根侵染也促进了绿豆的P营养.但接种DW1与DH3对菌根侵染率与绿豆生长都没有显著影响.3种菌剂无论是单独或者联合接种都能显著促进土壤中DEHP的降解,3种菌剂同时接种则对DEHP的降解能达到最好的协同作用,同时也减少DEHP在绿豆地上部分的累积,这为DEHP污染农田土壤的植物修复提供了理论依据.

A pot culture experiment was carried out to study the influences of arbuscular mycorrhizal （AM） fungi and bacteria on the bioremediation of DEHP polluted soil and the growth of mung bean. Bacillus sp. DW1 and Gordonia sp. DH3, two bacterial strains, as well as one AM fungal inoculum, Acaulospora laevis 90034 were alone or in combination applied to the soil with 100 mg·kg^-1 DEHP. Non-inoeulum was used as the control（CK）. The plants were harvested after 60 days of growth. The results showed that AM fungi could colonize the roots of mung bean. Shoot dry mass of the bean was increased by AMF inocula, although there was no significant difference of the root between each treatment. The AM fungi also improved plant mineral nutrition by increasing phosphorus （P） content, but there was no influence on root colonization and plant growth by DW1 and DH3. The two bacterial strains and the AM fungi, alone or in combination, promoted the degradation of DEHP in soil obviously. The combination inoculation with DW1, DH3 and AM fungi,exhibited a well synergistic effect on DEHP degradation, and it could decrease the DEHP uptake by shoots of mung bean, which indicates that co-inoculation technique can play a role in phytoremediation of DEHP-contaminated soils.