A cross-city molecular biogeographic investigation of arbuscular mycorrhizas in Conyza canadensis rhizosphere across native and non-native regions

Manzoor A Shah,Damase P Khasa,Marie-Eve Beaulieu,Salman Qureshi,Zafar A Reshi

doi:10.1186/s13717-015-0034-0

Manzoor A Shah, Damase P Khasa + Show 3 more

Open Access

https://doi.org/10.1186/s13717-015-0034-0

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Abstract

The ecological processes underlying the suppressive impacts of invasive species on native species diversity, both above- and below-ground, in non-native regions are not well understood. We therefore aimed to investigate the cross-city biogeographic patterns of arbuscular mycorrhizal (AM) diversity in Conyza canadensis rhizosphere in native (North American) and non-native (Kashmir Himalayan) regions. We recovered AMF spores from rhizospheric soils of Conyza in native and non-native ranges, besides doing so from the uninvaded sites in the introduced region. DNA extracted from AMF spores was processed for cloning and PCR-RFLP of SSU rRNA gene to yield the restriction groups (RGs) followed by their sequence analysis to determine the sequence groups (SGs). The results indicated greater diversity of RGs and SGs in Conyza rhizosphere in native than in non-native sites. In the introduced region, however, the AMF diversity was more in uninvaded than in invaded sites. The species composition of AMF varied significantly between native and non-native regions and so also between invaded and uninvaded habitats. Though difference in AMF diversity between Conyza invaded and uninvaded sites may be attributed to invasion, the role of other evolutionary factors seems likely for differences between the native and non-native regions. We suggest that the ecological processes underlying these evolutionary differences in two biogeographic regions, besides the intensity of urbanization, might play some role in these differences.

Highlights

The ecological processes underlying the suppressive impacts of invasive species on native species diversity, both above- and below-ground, in non-native regions are not well understood
The Kashmir Himalayan sites were highly invaded by C. canadensis and soil samples drawn from each of these sites and nearby similar uninvaded sites were transported to the Centre of Forestry Research, University Laval, Quebec, Canada, for analysis
The sites invaded by C. canadensis in Kashmir Himalaya from which soil samples were drawn represented almost monospecific stands, as opposed to the control sites in the Kashmir as well as the native North American sites where about seven to ten other species occurred at each site

Summary

Introduction

The ecological processes underlying the suppressive impacts of invasive species on native species diversity, both above- and below-ground, in non-native regions are not well understood. Arbuscular mycorrhizal symbiosis in view of its central role in plant-rhizosphere interactive dynamics is referred as the mother of plant root endosymbioses (Parniske 2008). These AMF may act as drivers of various ecological processes (Shah et al 2009). Understanding the impact of plant invasions on mycorrhizal diversity, an emerging challenge for contemporary ecologists, is beset with complexities due to the simultaneous operation of a multitude of biotic and abiotic factors at different eco-evolutionary scales (Shah et al 2009) and due to technical, methodological, and conceptual reasons (Green and Bohannan 2006).

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