| |
|
|
|
Pathogen population structure and epidemiology are keys to wheat crown rot and Fusarium head blight management
S.
Chakraborty A H,
C. J.
Liu A,
V.
Mitter A,
J. B.
Scott A,
O. A.
Akinsanmi B,
S.
Ali C,
R.
Dill-Macky D,
J.
Nicol E,
D.
Backhouse F,
S.
Simpfendorfer G
A
CSRIO Plant Industry, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Qld 4067, Australia.
B
Cooperative Research Centre for Tropical Plant Protection, Plant Pathology Building, 80 Meiers Road, Indooroopilly, Qld 4068, Australia.
C
Department of Plant Pathology, North Dakota State University, Fargo, ND 58105, USA.
D
Department of Plant Pathology, University of Minnesota, 495 Borlaug Hall, Saint Paul, MN 55108, USA.
E
International Maize and Wheat Improvement Centre (CIMMYT), Wheat Program, Regional Office, P.K. 39 Emek 06511, Ankara, Turkey.
F
School of Environmental Sciences and Natural Resources Management, The University of New England, Armidale, NSW 2351, Australia.
G
Tamworth Agricultural Institute, NSW Department of Primary Industries, Tamworth, NSW 2340, Australia.
H
Corresponding author. Email: sukumar.chakraborty@csiro.au
|  |
|
Australasian Plant Pathology 35(6) 643–655 http://dx.doi.org/10.1071/AP06068
Submitted: 4 March 2006
Accepted: 16 August 2006
Published online: 2 November 2006
Abstract
This paper summarises the key findings from recent research on the population genetics and epidemiology of Fusarium pathogens causing head blight and crown rot of wheat in Australia and how this information has enabled the screening and selection of wheat germplasm with improved resistance to Fusarium. By relating new findings to the current state of knowledge, the paper serves as a timely and critical review of the international literature. In Australia, both Fusarium pseudograminearum and F. graminearum can cause both crown rot and Fusarium head blight under artificial inoculation. However, the former species is more widespread and is predominantly associated with crown rot whereas F. graminearum is mainly associated with Fusarium head blight, with limited geographical distribution in and around the Liverpool Plains in northern New South Wales. Studies of population structure and genetics have revealed that both species are genotypically diverse with similar levels of genetic recombination despite Gibberella zeae, the teleomorph of F. graminearum, being homothallic and G. coronicola, the teleomorph of F. pseudograminearum, being heterothallic. A high-throughput and reliable crown rot bioassay has been developed and used to screen over 1500 wheat germplasms to select 17 lines with putative crown rot resistance. Key differences in pathogen biology and epidemiology between Australia and the USA have emerged from other recent collaborative studies, which show that macroconidia constitute the bulk of aerial Fusarium head blight inoculum in Australia, whereas ascospores are the dominant primary inoculum for Fusarium head blight worldwide. The limited spread of splash-dispersed macroconidia of F. graminearum probably explains the restricted geographical distribution of this species in Australia. Other research collaboration has compared the aggressiveness, mycotoxin production and genotypic polymorphisms of the pathogen population from Australia and the USA. These and other differences in pathogen adaptation emphasise that research outcomes from elsewhere must be tested for relevance before applying them to Australian farming systems.
Keywords:
germplasm screening.
|
|
|
|
| |
|
|
|
Australasian Plant Disease Notes
