Can arbuscular mycorrhizal fungi reduce Cd uptake and alleviate Cd toxicity of Lonicera japonica grown in Cd-added soils?

A greenhouse pot experiment was conducted to study the impact of arbuscular mycorrhizal fungi--Glomus versiforme (Gv) and Rhizophagus intraradices (Ri) on the growth, Cd uptake, antioxidant indices [glutathione reductase (GR), ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), ascorbate (ASA), glutathione (GSH) and malonaldehyde (MDA)] and phytochelatins (PCs) production of Lonicera japonica in Cd-amended soils. Gv and Ri significantly increased P acquisition, biomass of shoots and roots at all Cd treatments. Gv significantly decreased Cd concentrations in shoots and roots, and Ri also obviously reduced Cd concentrations in shoots but increased Cd concentrations in roots. Meanwhile, activities of CAT, APX and GR, and contents of ASA and PCs were remarkably higher in Gv/Ri-inoculated plants than those of uninoculated plants, but lower MDA and GSH contents in Gv/Ri-inoculated plants were found. In conclusion, Gv and Ri symbiosis alleviated Cd toxicity of L. japonica through the decline of shoot Cd concentrations and the improvement of P nutrition, PCs content and activities of GR, CAT, APX in inoculated plants, and then improved plant growth. The decrease of shoot Cd concentrations in L. japonica inoculated with Gv/Ri would provide a clue for safe production of this plant from Cd-contaminated soils.

[Dynamics of salinization land based on EVI series data and landscape pattern analysis in Songnen Plain: a case study in Da'an City].

The west part of Jilin Province is one of the most salinization regions in China and much attention has been paid to the dynamics and monitoring of the salinization land. Based on the land use data derived from TM images in 2000, 2005 and 2010 and the enhanced vegetation index (EVI) series data from 2000 to 2012 of Da'an City as a typical salinization region, we used landscape pattern analysis to elucidate the dynamics of salinization land, and used gray incidence method to analyze the main driving factors for the dynamics of land salinization. The results showed that the dominant land use types in Da'an City were cultivated land, grassland and salinization land. From 2000 to 2010, the area of salinization land and construction land showed an increasing trend, while that of grassland tended to decrease. Salinization land, which showed increased connectivity and integrity, was mainly transformed from grassland, swamp land and water area. Annual EVI values in Da'an City showed an overall increasing trend while the average values showed obvious spatial differences with the lowest EVI level in salinization land. From 2000 to 2012, the increment of vegetation cover area was larger than that of the degraded area. Landscape transformation affected the changing trends of EVI. Both natural factors and human activities affected the dynamics of salinization land, and human activities showed a greater impact on land salinization than climate factors.