Diversity and Roles of Mycorrhizal Fungi in the Bee Orchid Ophrys apifera



Abdullah, WR
(2018) Diversity and Roles of Mycorrhizal Fungi in the Bee Orchid Ophrys apifera. PhD thesis, University of Liverpool.

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Abstract

ABSTRACT Mycorrhiza is a crucial symbiotic association between the roots of plants and fungi within the soil environment. The specificity in these partnerships, particularly of the fungal partner is still poorly understood. Orchids require symbiotic fungi in a mycorrhizal association for seed germination and establishment, typically species within the Tulasnellaceae and Ceratobasidiaceae. The distribution of suitable mycorrhizal fungi will therefore affect the distribution of orchid plants. The bee orchid (Ophrys apifera) is considered common in southern England but is less frequent in the north. It has a conspicuous flower spike with individual flowers resembling bees. The species is surprisingly common in urban reclaimed ground where rubble provides suitable well-drained, alkaline and low nutrient conditions. Aboveground organs of Ophrys apifera were recorded over a 3-year period to understand the life history better. The basal leaf rosette starting appeared in September, flower shoot initiated at the end of April, and flowers opened in May and all organs above ground died in summer (July and August). There was a positive correlation between leaf length and leaf area, and there is no significant correlations between maximum number of leaves and maximum number of flowers. There was no obvious effect of temperature and rainfall, possibly due to stability of the weather during this period. Root and soil samples were analysed to identify potential mycorrhiza fungi. Culture-based techniques provided limited information, although this included one culture of a likely mycorrhizal genus. Samples from three sites of Liverpool University campus were investigated using Illumina amplicon sequencing of the ITS region. DNA of Tulasnellaceae and Ceratobasidaceae were detected in the soil as anticipated. In addition Sebacinaceae, Thelephoraceae, Clavariaceae, Psathyrellaceae were also detected in the soil samples. There were significant differences between the fungal communities of the three sites. A transcriptome analysis to provide insight into the orchid physiology was undertaken using protocorms derived from seed germinated in vitro and tissues of root and corm from the field. Determination of differentially expressed genes/transcripts showed specific ones were up-regulated in protocorm (e.g. related to auxin transport, carbohydrate metabolism) while others, (e.g. related to transport processes) were detected up-regulated in corm and root. These outcomes of these studies on Basidiomycota fungi and the Ophrys apifera host provide significant insight into the orchid mycorrhizal relationship

Item Type: Thesis (PhD)
Divisions: Fac of Health & Life Sciences > Faculty of Health and Life Sciences
Depositing User: Symplectic Admin
Date Deposited: 09 Aug 2018 14:20
Last Modified: 25 Aug 2019 07:10
URI: http://livrepository.liverpool.ac.uk/id/eprint/3022579
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