Arbuscular Mycorrhizas in Plant Roots from Naturally Radioactive Sites

Abstract

Uranium (U) is an element that occurs naturally in the Earth's crust and is relatively common, however, its presence may also be enhanced by anthropogenic causes such as mining and industrial activities. This situation can be aggravated because of an inaccurate management of nuclear wastes where, in addition, U may bepresent in many chemical forms providing more complex scenarios. Considering these two situations, U can be included in two categories: in Naturally-Occurring Radioactive Materials (NORM) and in Technologically-Enhanced, Naturally-Occurring Radioactive Materials (TENORM). It is known that symbiotic fungi can interact with certain U species making thisfungal group of special interest as it may have an important impact in terrestrial environments. Of particular interest for this current research project were arbuscular mycorrhizal fungi (AMF) which may have a major role in NORM and TENORM environments because of the interaction they have with certain U species, and because of the potential role that they have in decreasing the translocation of U intothe shoots of plants. This research was focused on the evaluation of arbuscular mycorrhizal colonisation of the roots of plant species from NORM and TENORM sites. Additionally, the same evaluation was carried out on roots of seedlings that were part of a turf based mesocosm experiment designed to characterise the accumulation of U (and possibly other radionuclides) into plant tissues and the role that AMF have in the mobilisation of such elements. It was found that the plant species examined from the NORM and TENORM sites were colonised by AMF to different extents. Two plant species (Oenanthe crocata and Chrysosplenium oppositifolium) that had previously been described as not being colonised by AM fungi were found positive for AM fungal colonisation. Unexpected results from the mesocosm experiment suggested that further work needs to be done focused on the sterilisation methods of the soil and set-up of the seedlings in the soil.

Date of Award	1 Aug 2016
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Clare Robinson (Supervisor) & Jon Pittman (Supervisor)