Ganoderma species, including new taxa associated with root rot of the iconic Jacaranda mimosifolia in Pretoria, South Africa.

Martin P. A. Coetzee,Seonju Marincowitz,Vuledzani G. Muthelo,Michael J. Wingfield

doi:10.5598/imafungus.2015.06.01.16

Martin P. A. Coetzee, Seonju Marincowitz + Show 2 more

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https://doi.org/10.5598/imafungus.2015.06.01.16

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Journal: IMA Fungus	Publication Date: Jun 1, 2015
Citations: 42	License type: CC BY 4.0

Affiliation: University of Pretoria

Abstract

Jacaranda mimosifolia trees have been progressively dying due to Ganoderma root and butt rot disease in Pretoria (the "City of Jacarandas") for many years. Ganoderma austroafricanum was described from these trees previously but this was based on a single collection. This study treats a substantially expanded collection of isolates of Ganoderma made from all dying trees where basidiomes were present in a Pretoria suburb. DNA sequences were obtained from the ITS and LSU region for the isolates and compared against sequences on GenBank. Phylogenetic analyses were used to compare sequences with those for other Ganoderma species. Based on sequence comparisons and morphological characters, two new Ganoderma species were discovered and these are described here as G. enigmaticum and G. destructans spp. nov. Interestingly, the previously described G. austroafricanum was not found, G. enigmaticum was found on only one Ceratonia siliqua tree and G. destructans was found on all other trees sampled. The latter species appears to be the primary cause of root rot of J. mimosifolia in the area sampled.

Highlights

The city of Pretoria (South Africa) is commonly known as the “City of Jacarandas”
Nine differences were observed between G. austroafricanum and the isolates from J. mimosifolia collected in this study
This would be consistent with the isolates having been collected in the general area where G. austroafricanum was first found, and the primary aim of our investigation was to obtain a larger collection of that fungus for possible use in a population genetics study

Summary

Introduction

The city of Pretoria (South Africa) is commonly known as the “City of Jacarandas”. This is because thousands of Jacaranda mimosifolia (Bignoniaceae) trees have been planted in its gardens, parks, and roadsides. The city is covered by a spectacular “blanket” of purple and this draws the interest of tourists and South African citizens alike. Any threat to these trees is seen as important and worthy of study. In South Africa, the first trees were introduced during the 1890s when two trees were planted at a school in Pretoria (Henderson 1990). Substantial numbers of these trees have, increasingly been dying since 1998 in the Pretoria suburb of Brooklyn due to a root rot disease apparently caused by a species of Ganoderma

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