深色有隔内生真菌对镉胁迫下芦竹生长、光合和矿质营养的影响

Effects of dark septate endophyte on the growth,photosynthesis and mineral nutrition of Arundo donax under cadmium stress

土壤镉污染已成为全球问题,菌根-植物共生体能够有效修复镉污染土壤。为了解芦竹接种深色有隔内生真菌(dark septate endophyte,DSE)后的耐镉机制,采用盆栽法,研究了镉胁迫下接种DSE对芦竹生长、光合作用和矿质营养的影响。结果表明:与对照相比,接种后显著增加芦竹的株高(12.97%~20.08%)、分蘖数(7.69%~45.45%)、地上生物量(18.97%~28.35%)等,并显著提高了表观量子效率(17.50%~46.77%)、暗呼吸速率(7.81%~52.42%)、根系全N(12.99%~40.60%)、全P(18.07%~38.18%)、全K(23.00%~48.67%)含量以及地上部(62.11%~91.87%)和根系(8.13%~71.01%)镉含量。镉胁迫下DSE对芦竹的影响因菌种不同而异,其中LZ01~LZ03处理的镉转移系数均大于1,LZ01-芦竹共生体是最佳组合。镉胁迫和DSE对芦竹的生长、光合、矿质养分含量具有显著的交互作用,且三者间存在显著的相关性。试验表明,镉胁迫下接种DSE能促进芦竹生长,增强其光合作用,提高矿质营养含量,同时增强了芦竹对镉的吸收和转运能力。DSE-芦竹共生体具有较强的抗镉胁迫能力,在镉污染土壤修复中具有潜在应用前景。

Cadmium( Cd) pollution in soil is a global problem. Mycorrhizal-plant symbiosis can effectively repair Cd-contaminated soil. To understand the cadmium tolerance mechanism of Arundos donax inoculated with dark septate endophyte( DSE),a pot experiment was carried out to investigate the effects of DSE inoculation on the growth,photosynthesis and mineral nutrition of A.donax under Cd stress. The results showed that inoculation of DSE significantly improved the growth of A. donax under Cd stress. Compared with CK,plant height,number of tillers,and aboveground biomass were increased by 12. 97%-20. 08%,7. 69%-45. 45%,and 18. 97%-28.35%,respectively. In addition,the apparent quantum rate and dark respiration rate were increased by 17.50%-46.77% and 7.81%-52.42%. The concentrations of total N,P,and K in roots were increased by 12.99%-40.60%,18.07%-38.18%,and 23.00%-48.67%,respectively.The Cd concentrations in shoots and roots were significantly increased by 62.11%-91.87% and8.13%-71.01%,respectively. The effects of DSE on A. donax under Cd stress varied with strains inoculated. The Cd translocation factor of LZ01-LZ03 treatments were all greater than 1. The LZ01-A. donax symbiont was the best combination under the experimental conditions. Cd stress and DSE had a significant interaction effect on the growth,photosynthesis and nutrient concentration of A. donax,with significant correlations among these three traits. The results indicated that inoculation with DSE can promote the growth and photosynthesis of A. donax,increase mineral nutrition,and enhance Cd absorption and transportation of A. donax under Cd stress. DSE-A.donax symbiont is relatively resistant to Cd stress,with potential application prospect to Cd contaminated soil remediation.