施用生物炭和AM真菌对镉胁迫下玉米生长和生理生化指标的影响

Effects of biochar amendment and arbuscular mycorrhizal inoculation on maize growth and physiological biochemistry under cadmium stress

为了探究镉(cadimum,Cd)胁迫下生物炭和丛枝菌根(arbuscular mycorrhizal,AM)对植物生长的协同效应,采用盆栽试验,研究在3个Cd污染(0,3,6mg Cd·kg-1)水平下,施用小麦秸秆生物炭和接种AM真菌(Glomus intraradices BEG 141)对玉米生长和生理生化特性的影响。结果表明,施用生物炭和接种AM真菌单独或复合处理均能提高玉米的株高、生物量、光合色素含量、光合特性和抗氧化酶活性,降低胞间CO2浓度(Ci)、MDA含量。接种AM真菌促进玉米生长效果优于生物炭,而生物炭对提高土壤pH效果较好,施用生物炭和接种AM真菌复合处理对Cd胁迫下玉米生长和改善玉米生理生化特性的促进效应最佳。其中,在6mg Cd·kg-1水平下,施用生物炭和接种AM真菌复合处理使株高、生物量分别增加43.87%、79.10%;净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)分别提高33.09%,45.04%,31.27%;叶片的超氧化物歧化酶(superoxide dismutase,SOD)活性、过氧化物酶(peroxidase,POD)活性、过氧化氢酶(catalase,CAT)活性分别提高51.42%,82.91%,43.96%。综合来看,生物炭和AM真菌单独或复合处理均能够减轻Cd胁迫和促进植物生长,以生物炭和AM真菌复合处理效果最佳,AM真菌处理效果次之,生物炭处理效果较差。

To explore the synergistic effects of biochar and arbuscular mycorrhizal fungi（AM）on plant grown in cadmium（Cd）contaminated soil,we conducted a pot experiment to investigate the effect of wheat-straw biochar amendment and AM inoculation（Glomus intraradices BEG 141）on maize（Zea mays）growth and physiological biochemistry characteristics with soil contaminated with 0,3 or 6 mg Cd·kg-1 soil.The results showed that applying either biochar or AM inoculant alone or in combination all significantly increased maize growth,photosynthetic pigment content,photosynthesis and antioxidant enzymatic activities while decreasing intercellular CO2 concentration（Ci）and MDA content.Compared with biochar application and AM inoculation,AM inoculation alone was effective at alleviating Cd stress and facilitating maize growth while biochar alone was more effective at inducing soil alkalinization.Amending soil with biochar and AM inoculant together produced the largest increase in maize growth and physiological biochemistry characteristics.This effect was additive,with 43.87% and 79.10% greater plant height and biomass,33.09%,45.04% and 31.27% higher net photosynthetic rate（Pn）,transpiration rate（Tr）and stomatal conductance（Gs）,and 51.42%,82.91% and 43.96% higher superoxide dismutase（SOD）,peroxidase（POD）and catalase（CAT）activity,respectively,at a 6 mg·kg-1 Cd contamination rate.In general,biochar and AM inoculation alone or in combination all improved maize growth and alleviated Cd toxicity.Biochar addition in combination with AM inoculation application was the most effective treatment but AM inoculation alone was more effective than biochar for increasing the resistance of Cd toxicity and improving maize growth in Cd-contaminated soil.