A QTL located on chromosome 4A associated with dormancy in white- and red-grained wheats of diverse origin
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Improved resistance to preharvest sprouting in modern bread wheat (Triticum aestivum. L.) can be achieved via the introgression of grain dormancy and would reduce both the incidence and severity of damage due to unfavourable weather at harvest. The dormancy phenotype is strongly influenced by environmental factors making selection difficult and time consuming and this trait an obvious candidate for marker assisted selection. A highly significant Quantitative Trait Locus (QTL) associated with grain dormancy and located on chromosome 4A was identified in three bread wheat genotypes, two white- and one red-grained, of diverse origin. Flanking SSR markers on either side of the putative dormancy gene were identified and validated in an additional population involving one of the dormant genotypes. Genotypes containing the 4A QTL varied in dormancy phenotype from dormant to intermediate dormant. Based on a comparison between dormant red- and white-grained genotypes, together with a white-grained mutant derived from the red-grained genotype, it is concluded that the 4A QTL is a critical component of dormancy; associated with at least an intermediate dormancy on its own and a dormant phenotype when combined with the R gene in the red-grained genotype and as yet unidentified gene(s) in the white-grained genotypes. These additional genes appeared to be different in AUS1408 and SW95-50213.
KeywordsQuantitative Trait Locus Double Haploid Line Germination Index Significant Quantitative Trait Locus Seed Coat Colour
Financial support from the Grains Research and Development Corporation and the Australian Centre for International Agricultural Research is gratefully acknowledged.
- Flintham JE, Gale MD (1996) Dormancy gene maps in homologous cereal genomes. In: Noda K, Mares DJ (eds) Preharvest Sprouting in Cereals 1995. Centre for Academic Societies, Osaka, Japan, pp 143–149Google Scholar
- Flintham JE, Adlam R, Gale MD (1999) Seedcoat and embryo dormancy in wheat. In: Weipert D (eds) Eighth International Symposium on Preharvest Sprouting in Cereals 1998. Association of Cereal Research, Federal Centre for Cereal Potato, and Lipid Research, Detmold, Germany, pp 67–76Google Scholar
- McIntosh RA, Hart GE, Devos KM, Gale MD (1995) Catalogue of gene symbols for wheat. 1995 supplement. Ann Wheat Newslett 41:330–335Google Scholar
- Mares DJ (1987) Pre-harvest sprouting tolerance in white-grained wheat. In: Mares SJ (ed) Fourth international symposium on preharvest sprouting in cereals, Westview Press, Boulder pp 64–74Google Scholar
- Mares DJ (1989) In: Derera NF (ed) Preharvest sprouting damage and sprouting tolerance assay methods and instrumentation (Preharvest Field Sprouting in Cereals). CRC, Boca Raton, pp 130–166Google Scholar
- Mares DJ (1993) Genetic studies of sprouting tolerance in red and white wheats. In: Walker-Simmons K, Reid JL (eds) Preharvest sprouting in Cereals 1992. AACC, St Paul, MN, USA, pp 21–9Google Scholar
- Mares DJ (1996) Dormancy in white wheat : mechanism and location of genes. In: Noda K, Mares DJ (eds) Preharvest Sprouting in Cereals 1995’. Centre for Academic Societies, Osaka, Japan, pp 179–184Google Scholar
- Mares DJ (1999) The seed coat and dormancy in wheat grains. In: Weiprt D (ed) Eighth International Symposium on Preharvest Sprouting in Cereals 1998’. Association of Cereal Research Federal Centre for Cereal Potato and Lipid Research. Detmold, Germany, pp 77–81Google Scholar
- Ramsay L, Macaulay M, Ivanissivich S degli, MacLean K, Cardle L, Fuller J, Edwards K, Tuvesson S, Morgante M, Massari A, Maesti E, Marmiroli N, Sjakste T, Ganal M, Powell W, Waugh R (2000) A simple sequence repeat-based linkage map of barley. Theor Appl Genet 156:1997–2005Google Scholar
- Warner RL, Kurdna DA, Spaeth SC, Jones SS (2000) Dormancy in white-grained mutants of Chinese Spring wheat (Triticum aestivum L.). Seed Sci Res 10:51–60Google Scholar