Identity and genetic diversity of the sorghum ergot pathogen in Australia

Komolong, Birte, Chakraborty, Sukumar, Ryley, Malcolm and Yates, David (2002) Identity and genetic diversity of the sorghum ergot pathogen in Australia. Australian Journal of Agricultural Research, 53 6: 621-628. doi:10.1071/AR01135


Author Komolong, Birte
Chakraborty, Sukumar
Ryley, Malcolm
Yates, David
Title Identity and genetic diversity of the sorghum ergot pathogen in Australia
Journal name Australian Journal of Agricultural Research   Check publisher's open access policy
ISSN 0004-9409
Publication date 2002-01-01
Sub-type Article (original research)
DOI 10.1071/AR01135
Volume 53
Issue 6
Start page 621
End page 628
Total pages 8
Place of publication Collingwood, VIC
Publisher CSIRO Publishing
Language eng
Subject C1
270403 Plant Pathology
620104 Other cereals
Abstract Sorghum ergot was first discovered in Australia in 1996. It affects seed production and grain usage in stock feed due to concerns of animal toxicity. Three species of Claviceps are known to cause ergot of sorghum with different epidemiological, animal toxicity, and management implications. Claviceps africana was identified as the causal agent but morphological differences between isolates raised the possibility of more than one species being involved. The major aim of this study was to identify the Claviceps species causing sorghum ergot and to determine the genetic diversity among isolates of the ergot pathogen from Australia and overseas. Symptom development, sequencing of the ITS1 region, and radiolabelled DNA amplification fingerprints (RAF) were used to confirm that ergot of sorghum in Australia is caused by C. africana. The morphology of sphacelia, microconidia, macroconidia, and secondary conidia of all 36 Australian isolates studied matched the description for C. africana and the DNA sequence of the ITS1 region of 2 selected Australian isolates was identical to that of C. africana. Based on RAF analysis of 110 Australian and overseas isolates of Claviceps spp., C. africana isolates could be clearly distinguished (<40% similarity) from C. pusilla, C. sorghicola, C. sorghi, and a Claviceps sp. isolated from Panicum maximum. The C. africana isolates formed 2 distinct clusters. Cluster 1 contained 72 Australian isolates and all 21 overseas isolates of C. africana. The 13 isolates in Cluster 2 were all from Australia and more diverse than those in Cluster 1. The high level of genetic diversity of C. africana isolates in Australia is unexpected given that ergot has only been reported recently. The most likely source of this diversity points to introductions from countries such as India.
Keyword Agriculture, Multidisciplinary
Claviceps Africana
Its1
Molecular Markers
Raf
Claviceps-africana
Disease
America
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Agriculture and Food Sciences
 
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Created: Wed, 15 Aug 2007, 03:28:31 EST