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Molecular Plant Breeding 2012, Vol.3, No.8, 80
-
90
http://mpb.sophiapublisher.com
80
Research Report Open Access
Development and Validation of Markers Closely Linked to Crown Rot Resistance
in Wheat and Barley
H.B. Li
1
, M.X. Zhou
2
, C.J. Liu
1
1. CSIRO Plant Industry, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, QLD 4067, Australia
2. Tasmanian Institutes of Agricultural Research and School of Agricultural Science, University of Tasmania, P.O. Box 46, Kings Meadows, Tasmania 7250,
Australia
Corresponding authors email: Haobing.Li@dpi.vic.gov.au;
Authors
Molecular Plant Breeding, 2012, Vol.3, No.8 doi: 10.5376/mpb.2012.03.0008
Received: 04 May, 2012
Accepted: 16 May, 2012
Published: 20 Jun., 2012
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Li et al., 2012, Development and Validation of Markers Closely Linked to Crown Rot Resistance in Wheat and Barley, Molecular Plant Breeding, Vol.3, No.8
80
-
90 (doi: 10.5376/mpb.2012.03.0008)
Abstract
Crown rot (CR), caused by various
Fusarium
species, is a chronic cereal disease in Australia and many other parts of the
world. As part of our objective of improving the efficiency of breeding CR-resistant wheat and barley varieties, we have been
searching for novel sources of resistance and identifying new genes conferring CR resistance in the two crops. This paper reports on
the development of more closely linked markers and validation of the effects of the previously identified wheat 3B CR quantitative
trait loci (QTL) and the barley 3H major CR locus using four wheat and three barley validation populations. With an effect varied
from 36.7 to 59.4% in wheat and 29.4 to 55.2% in barley, the validation experiments demonstrated that both of the 3B and 3H CR
locus have a stable and significant effect in reducing CR severity at different genetic backgrounds. The huge effect of a single QTL as
the CR loci detected in this study warrant a significant value of incorporating these two genes in wheat and barley breeding. The
possible homoeologous relationship between these two major CR loci is preliminarily investigated by comparative mapping the two
genomic regions and it warrants further investigation.
Keywords
Wheat; Barley; Crown rot; Validation; Comparative mapping
Background
Crown rot (CR) is a severe and chronic disease of
cereals found in many parts of the world (Chakraborty
et al., 2006). Both barley and wheat can be seriously
affected by CR, which has recently become more
prevalent due to the widespread adoption of minimum
tillage (reviewed by Chakraborty et al., 2006) as CR
pathogens are carried over in residues (Wildermuth et
al., 1997; Wallwork et al., 2004). A recent study by
Daniel and Simpfendorfer (2008) found that, on
average, CR caused 25% yield loss in bread wheat,
58% in durum, and 20% in barley across a wide range
of environments in Australia. A survey in the Pacific
Northwest of the USA found that CR could reduce
yield of winter wheat by 35% and barley by 13% in
commercial fields (Smiley et al., 2005). In addition to
yield loss, CR infected plants in glasshouse assays have
been shown to contain mycotoxins (Mudge et al., 2006),
which may potentially have adverse health effects if
high levels are present in food and feed products.
Growing resistant varieties has long been recognised
as the most effective way to minimize CR damage,
and there have been efforts in breeding CR resistance
in Australia. However, varieties with high levels of
resistance are not yet available. Studies on CR have
mainly considered disease incidence and severity with
very few reports on yield loss. It was reported that
effects of CR are slightly different for wheat and
barley (Smiley et al., 2005; Daniel and Simpfendorfer,
2008). These studies support the notion that, although
barley gets more severe CR symptoms than bread
wheat (Wildermuth and Purss, 1971; Burgess et al.,
1987; Klein et al., 1989), they are more tolerant to CR
infection and suffer less yield loss than wheat.
A few of the wheat genotypes with moderate CR
resistance have been identified and used for molecular
mapping studies. The first study reported the CR