Fine mapping of a large-effect QTL conferring Fusarium crown rot resistance on the long arm of chromosome 3B in hexaploid wheat.
BACKGROUND
Fusarium crown rot (FCR) is a major cereal disease in semi-arid areas worldwide. Of the various QTL reported, the one on chromosome arm 3BL (Qcrs.cpi-3B) has the largest effect that can be consistently detected in different genetic backgrounds. Nine sets of near isogenic lines (NILs) for this locus were made available in a previous study. To identify markers that could be reliably used in tagging the Qcrs.cpi-3B locus, a NIL-derived population consisting of 774 F10 lines were generated and exploited to assess markers selected from the existing linkage map and generated from sequences of the 3B pseudomolecule.


RESULTS
This is the first report on fine mapping a QTL conferring FCR resistance in wheat. By three rounds of linkage mapping using the NILs and the NIL-derived population, the Qcrs.cpi-3B locus was mapped to an interval of 0.7 cM covering a physical distance of about 1.5 Mb. Seven markers co-segregating with the locus were developed. This interval contains a total of 63 gene-coding sequences based on the 3B pseudomolecule, and six of them were known to encode disease resistance proteins. Several of the genes in this interval were among those responsive to FCR infection detected in an earlier study.


CONCLUSIONS
The accurate localization of the Qcrs.cpi-3B locus and the development of the markers co-segregating with it should facilitate the incorporation of this large-effect QTL conferring FCR resistance into breeding programs as well as the cloning of the gene(s) underlying the QTL.
CSIRO Agriculture, 306 Carmody Road, St Lucia, QLD, 4067, Australia. zhengzhi1103@aliyun.com.|School of Plant Biology, Faculty of Science and The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia. zhengzhi1103@aliyun.com.|National Foxtail Millet Improvement Centre, Institute of Millet Crops, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang, China. zhengzhi1103@aliyun.com.
Zhi
Z
Zheng
CSIRO Agriculture, 306 Carmody Road, St Lucia, QLD, 4067, Australia. plantgbmj@hotmail.com.|Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China. plantgbmj@hotmail.com.
Jian
J
Ma
CSIRO Agriculture, 306 Carmody Road, St Lucia, QLD, 4067, Australia. jiri.stiller@csiro.au.
Jiri
J
Stiller
National Center for Gene Research, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 500 Caobao Road, Shanghai, 200233, China. zqiang@ncgr.ac.cn.
Qiang
Q
Zhao
National Center for Gene Research, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 500 Caobao Road, Shanghai, 200233, China. qfeng@ncgr.ac.cn.
Qi
Q
Feng
INRA-UBP Joint Research Unit 1095, Genetics, Diversity and Ecophysiology of Cereals Clermont-Ferrand, Clermont-Ferrand, F-63100, France. frederic.choulet@clermont.inra.fr.
Frédéric
F
Choulet
INRA-UBP Joint Research Unit 1095, Genetics, Diversity and Ecophysiology of Cereals Clermont-Ferrand, Clermont-Ferrand, F-63100, France. catherine.feuillet@bayer.com.
Catherine
C
Feuillet
Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China. ylzheng@sicau.edu.cn.
You-Liang
YL
Zheng
Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China. ymwei@sicau.edu.cn.
Yuming
Y
Wei
National Center for Gene Research, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 500 Caobao Road, Shanghai, 200233, China. bhan@ncgr.ac.cn.
Bin
B
Han
National Foxtail Millet Improvement Centre, Institute of Millet Crops, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang, China. guijun.yan@uwa.edu.au.
Guijun
G
Yan
CSIRO Agriculture, 306 Carmody Road, St Lucia, QLD, 4067, Australia. john.manners@csiro.au.
John M
JM
Manners
CSIRO Agriculture, 306 Carmody Road, St Lucia, QLD, 4067, Australia. chunji.liu@csiro.au.|School of Plant Biology, Faculty of Science and The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, 6009, Australia. chunji.liu@csiro.au.
Chunji
C
Liu
D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D060467:Disease Resistance / Q000235:genetics*; D005670:Fusarium / Q000235:genetics / Q000472:pathogenicity; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D040641:Quantitative Trait Loci / Q000235:genetics; D014908:Triticum / Q000235:genetics* / Q000382:microbiology