Role of Arbuscular Mycorrhizal Fungi in Fighting Soil Salinity

Ebrahim Ebrahim

Research output: ThesisDoctoral Thesis

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Abstract

The evaluation of mycorrhizas role in fighting soil salinity and sustaining plant growth under stress was extensively studied. However, very few studies are currently available to address the role of different mycorrhizal species or the consequences of using single or mix consortia of mycorrhizas in fighting soil salinity. To the best of my knowledge, no studies are available that examine the combined effect of using mycorrhizas under salt stress on the plant second generation. In the present study, the first set of experiments was conducted using mixed species of mycorrhizas provided by a specialised commercial company. The second set of experiments utilised individual species of Glomus etunicatum and G. mosseae. Two salt types were used to examine the effect of salt chemical structure on mycorrhizal-plant interactions. NaCl salt was used initially followed by a mixed combination of salts in subsequent experiments. Three levels of salinity stress were applied which were categorised into low (1-4 dS/m), medium (5-8 dS/m) and high salinity effect (> 9 dS/m). The focal plant used in this study was Ribwort Plantain (Plantago lanceolata). All experiments were conducted in controlled condition (controlled room & glasshouse) as well as in field conditions during the summer season. Different vegetation parameters were recorded for the first generation plants at the end of each experiment and seed germination testing was conducted for the second generation. The mix of commercial mycorrhizas failed to colonize the plant under the controlled room condition; however, in the glasshouse and the field areas the mixed mycorrhizas successfully colonized the plant roots. Root colonization was also successfully observed with the individual species of mycorrhizas under the salt stress in both controlled and field condition. Using mixed salt reduced plant growth more severely than using NaCl with the different mycorrhizal species. Different treatments of mycorrhizas were helpful for the plant only up to the medium level of salinity, while at the higher level of stress mycorrhizas failed to support the plant. The effect of mycorrhizas on the plant second generation was weak under different salinity stress, and in some experiments it failed to show any positive results on the second generation growth. Overall, the theory of Functional Complimentarity for mycorrhizal species was not supported in this study as using single species of mycorrhizas were more successful than mixed species under salinity stress in some situations.
Original languageEnglish
QualificationPh.D.
Awarding Institution
  • Royal Holloway, University of London
Supervisors/Advisors
  • Gange, Alan, Supervisor
Award date1 Aug 2014
Publication statusUnpublished - 14 Jul 2014

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