14 research outputs found
The Botryosphaeriaceae: genera and species known from culture
In this paper we give an account of the genera and species in the Botryosphaeriaceae. We consider morphological characters alone as inadequate to define genera or identify species, given the confusion it has repeatedly introduced in the past, their variation during development, and inevitable overlap as representation grows. Thus it seems likely that all of the older taxa linked to the Botryosphaeriaceae, and for which cultures or DNA sequence data are not available, cannot be linked to the species in this family that are known from culture. Such older taxa will have to be disregarded for future use unless they are epitypified. We therefore focus this paper on the 17 genera that can now be recognised phylogenetically, which concentrates on the species that are presently known from culture. Included is a historical overview of the family, the morphological features that define the genera and species and detailed descriptions of the 17 genera and 110 species. Keys to the genera and species are also provided. Phylogenetic relationships of the genera are given in a multi-locus tree based on combined SSU, ITS, LSU, EF1-α and β-tubulin sequences. The morphological descriptions are supplemented by phylogenetic trees (ITS alone or ITS + EF1-α) for the species in each genus.We would like to thank the curators of the numerous fungaria and Biological Resource Centres cited in this paper, for making specimens and cultures available for examination over the past 15 yr, without which this study would not have been possible. Part of this work was supported by Fundação para a Ciência e a Tecnologia (Portugal) through grant PEst-OE/BIA/UI0457/2011. Artur Alves and Alan Phillips were supported by the programme Ciência 2008, co-funded by the Human Potential Operational Programme (National Strategic Reference Framework 2007–2013) and the European Social Fund (EU).publishe
Frankincense in peril
The harvest of plant parts and exudates from wild populations contributes to the income, food security and livelihoods of many millions of people worldwide. Frankincense, an aromatic resin sourced from natural populations of Boswellia trees and shrubs, has been cherished by world societies for centuries. Boswellia populations are threatened by over-exploitation and ecosystem degradation, jeopardizing future resin production. Here, we reveal evidence of population collapse of B. papyrifera—now the main source of frankincense—throughout its geographic range. Using inventories of 23 populations consisting of 21,786 trees, growth-ring data from 202 trees and demographic models on the basis of 7,246 trees, we find that over 75% of studied populations lack small trees, natural regeneration has been absent for decades, and projected frankincense production will be halved in 20 yr. These changes are caused by increased human population pressure on Boswellia woodlands through cattle grazing, frequent burns and reckless tapping. A literature review showed that other Boswellia species experience similar threats. Populations can be restored by establishing cattle exclosures and fire-breaks, and by planting trees and tapping trees more carefully. Concerted conservation and restoration efforts are urgently needed to secure the long-term availability of this iconic product
Three genetic groups of the Eucalyptus stem canker pathogen Teratosphaeria zuluensis introduced into Africa from an unknown source
The Eucalyptus stem canker pathogen Teratosphaeria zuluensis was discovered in South
Africa in 1988 and it has subsequently been found in several other African countries as well
as globally. In this study, the population structure, genetic diversity and evolutionary history
of T. zuluensis were analysed using microsatellite markers to gain an enhanced understanding
of its movement in Africa. Isolates were collected from several sites in Malawi, Mozambique,
Uganda and Zambia. Data obtained were compared with those previously published for a
South African population. The data obtained from 334 isolates, amplified across eight
microsatellite loci, were used for assignment, differentiation and genetic diversity tests.
STRUCTURE analyses, θst and genetic distances revealed the existence of two clusters, one
dominated by isolates from South Africa and the other by isolates from the Zambezi basin
including Malawi, Mozambique and Zambia. High levels of admixture were found within and
among populations, dominated by the Mulanje population in Malawi. Moderate to low
genetic diversity of the populations supports the previously held view that the pathogen was
introduced into Africa. The clonal nature of the Ugandan population suggests a very recent
introduction, most likely from southern Africa.National Research Foundation of South Africa (Grant specific unique reference number (UID83924).http://link.springer.com/journal/104822017-01-31hb2016Forestry and Agricultural Biotechnology Institute (FABI)Microbiology and Plant PathologyPlant Production and Soil Scienc