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

Advances in winter pulse pathology research in Australia

Pulse crops in Australian broad-acre agriculture are a relatively small but essential component of present-day farming systems. Winter pulses, particularly the five accounted for in this review, dominate pulse area and production in this country. The Australian pulse industry has experienced devastating epidemics of diseases such as lupin anthracnose and chickpea ascochyta blight. In addition, many other diseases have appeared regionally. Research on various aspects was directed towards managing these diseases in individual regions, states and nationally. This review addresses advances in pathology related to bacterial, fungal and viral pathogens in lupins, chickpeas, field peas, lentils and faba beans. In addition to fundamental epidemiological and disease control studies, this paper includes molecular studies and quantitative epidemiology leading to disease modelling and disease forecasting. It also highlights the efforts undertaken recently by pulse pathologists in Australia to strengthen collaborative research nation-wide.No Full Tex