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Theor Appl Genet (2014) 127:18431855 DOI 10.1007/s00122-014-2345-4
ORIGINAL PAPER
Fine mapping of a preharvest sprouting QTL interval on chromosome 2B in white wheat
Suthasinee Somyong Goro Ishikawa
Jesse D. Munkvold James Tanaka David Benscher YongGu Cho Mark E. Sorrells
Received: 4 May 2014 / Accepted: 7 June 2014 / Published online: 2 July 2014 Springer-Verlag Berlin Heidelberg 2014
were developed by backcrossing selected doubled haploids to a recurrent parent and self-pollinating the BC1F4 and
BC1F5 generations. In each generation, three markers in the QPhs.cnl-2B.1 interval were used to screen for recombinants. Fine mapping revealed that the QPhs.cnl-2B.1 interval contained two PHS QTLs linked in coupling. The distal PHS QTL, located between Wmc453c and Barc55, contributed 8 % of the phenotypic variation and also co-located with a major seed dormancy QTL determined by germination index. The proximal PHS QTL, between Wmc474 and CNL415-rCDPK, contributed 16 % of the variation. Several candidate genes including Mg-chelatase H subunit family protein, GTP-binding protein and calmodulin/Ca2+-dependent protein kinase were linked to the PHS QTL. Although many recombinant lines were identied, the lack of polymorphism for markers in the QTL interval prevented the localization of the recombination breakpoints and identication of the gene underlying the phenotype.
Abstract
Key message Fine mapping by recombinant backcross populations revealed that a preharvest sprouting QTL on 2B contained two QTLs linked in coupling with dif ferent effects on the phenotype.
Abstract Wheat preharvest sprouting (PHS) occurs when grain germinates on the plant before harvest, resulting in reduced grain quality. Previous mapping of quantitative trait locus (QTL) revealed a major PHS QTL, QPhs.cnl-2B.1, located on chromosome 2B signicant in 16 environments that explained from 5 to 31 % of the phenotypic variation. The objective of this project was to ne map the QPhs.cnl-2B.1 interval. Fine mapping was carried out in recombinant backcross populations (BC1F4 and BC1F5) that
Communicated by Yunbi Xu.
S. Somyong and G. Ishikawa have contributed equally to this work.
Electronic supplementary material The online version of this article (doi:http://dx.doi.org/10.1007/s00122-014-2345-4
Web End =10.1007/s00122-014-2345-4 ) contains supplementary material, which is available to authorized users.
S. Somyong G. Ishikawa J. D. Munkvold J. Tanaka D. Benscher Y.-G. Cho M. E. Sorrells (*)
Department of Plant Breeding and Genetics, Cornell University, 240 Emerson Hall, Ithaca, NY 14853,...