Establishment of arbuscular mycorrhizal plants originating from xerothermic grasslands on heavy metal rich industrial wastes–new solution for waste revegetation

Abstract

Industrial waste substrata, rich in heavy metals, are poorly suited for plant growth. Efforts are made to establish an appropriate plant cover to reduce erosion and further contamination. Grasses are the usual solution, as they grow fast, thrive on poor substrata and have well-developed root systems. Some of them are also highly dependent on mycorrhizal symbiosis that supports their growth especially on poor and polluted soils. However, the commercially available grasses often meet a lack of well established mycorrhiza on the site and the introduced plant populations dramatically decrease with time, despite large financial input including covering the substratum with soil and intensive watering. The aim of this paper was to select proper plants together with mycorrhizal fungi that could accelerate the establishment of the vegetation and improve its diversity under these extreme conditions, minimizing the financial costs of the reclamation (no use of soil layering and watering). The experiments were carried out under field and laboratory conditions. The plant seeds used originated from dry calcareous grasslands. The seeds were germinated under field conditions or in pots filled with soil supplemented with substratum from the industrial wastes. The seedlings were inoculated with AM fungi and introduced on the field plots a few weeks after germination. The inoculum consisted of either crude inoculum harvested from the dry calcareous grasslands or strains originating from polluted areas. Plants colonized by mycorrhizal fungi established well in the experimental plots. The results suggest that inocula from dry calcareous grasslands are potentially useful in revegetation of industrial wastes. Although in several cases the photosynthetic activity of plants was lower than at the natural sites, almost all plants survived and formed seeds. In all experiments the plant vitality was estimated on the Plant Soil (2008) 305:267-280 basis of chlorophyll a fluorescence and was useful to show differences between waste substrata, inocula and coexisting plant species. The interactions between mycorrhizal and non-mycorrhizal plants were studied under greenhouse conditions and at least no negative effect of this coexistence was found.

Arbuscular mycorrhizal colonisation of roots of grass species differing in invasiveness

“…ischaemum (Shah et al 2009a, Wilson et al 2012, B. pinnatum (van der Heijden et al 1998, Endresz et al 2005, B. inermis (Turnau et al 2008, Shah et al 2009a, C. epigeijos (Rydlová andVosátka 2001, van der Staaij et al 2001) and C. dactylon (Cabello 1997, Lingfei et al 2005). …”

Metal uptake by xerothermic plants introduced into Zn-Pb industrial wastes

“…by Dzwonko andLoster (1998) andBąba (2004). In the present study, seeds of the following plant species were collected: sulcata) studied in the present paper were not investigated in our previous research (Turnau et al 2008) because they were introduced into the tailings later. Moreover, several species that were included in previous studies were omitted here due to poor growth at the time of sampling.…”

“…Our previous research on plants and their symbiotic associations occurring spontaneously on the Zn-Pb waste in Chrzanów revealed that the most successful colonizers of such sites are species which originate from xerothermic grasslands (reviewed by Turnau et al 2006). In 2004, 23 plant species, pre-cultivated in the presence of mycorrhizal inoculum, were introduced on experimental plots (Turnau et al 2008). The introduced plants survived and to the naked eye, they did not differ much from individuals growing in the wild.…”

Heavy Metal-Induced Differential Responses to Oxidative Stress and Protection by Mycorrhization in Sunflowers Grown in Lab and Field Scales

“…What is interesting, in contrast with very contaminated substrates such as mine tailings [12][13][14], is that the response of oxidative stress variables for plants grown in unpolluted or slightly polluted soils presents similar patterns of variation in almost all plant parts. However, plants benefit from the effect of mycorrhizal fungi even in such substrates because the fungi enhance drought resistance in them [17,54]. Also, Clemens [7] states that HM stress up-regulates SOD and POD, but that high metal concentrations in plants can also lower the activity of these enzymes either through binding and direct inactivation, or through glutathione consumption.…”