Mycorrhizosphere development and management: The role of nutrients, micro-organisms and bio-chemical activities

摘要

The selection of pollutant tolerant plant, rhizosphere process and their proper management and establishment is crucial for successful phytoremediation experiment. To carry out rhizospheric bioremediation studies under the influence of mycorrhiza for the better survival of the plants, a cost effective method for the mass production of mycorrhizal inoculum is prerequisite. In the present research study, soil based mycorrhizal inoculum has been developed using Sorghum as a host plant in green house for a period of 75 days using pot culture technique. The physico-chemical characteristics, mycorrhizal status, Acid phosphatase activity (ACP), alkaline phosphatase activity (ALP), dehydrogenase activity (DHA) along with the number and diversity of bacteria, fungi and actinomycetes were assessed at a frequency of 15 days in the rhizospheric soil samples. Development of mycorrhizae was characterized by AM spore count and colonized root length percentage (%CRL) in Sorghum. Our data showed that soil nitrogen (N), organic carbon (C), organic phosphorus (Po), C/N and N/P ratio significantly increased with an increase in spore count and AM colonization. ACP, ALP and microbial activity (as represented by viable counts and DHA) were also found to be increasing during the process of mycorrhiza development. Thus developing mycorrhizae induce a series of changes in nutrient availability, microbial composition and enzymatic activities in the soil that may determine the outcome of a phytoremediation attempt. Developed mycorrhizal inoculum in the present study can contribute in establishing an effective mycorrhizosphere that can provide the environment for enhanced degradation of pollutants present in the soil.