Identification of genomic regions associated with seed dormancy in white-grained wheat

Author： Singh Rajender Matus-Cádiz Maria Båga Monica Hucl Pierre Chibbar Ravindra

ISSN： 0014-2336

Source： Euphytica, Vol.174, Iss.3, 2010-08, pp. : 391-408

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Abstract

Pre-harvest sprouting (PHS) in developing wheat (Triticum aestivum L.) spikes is stimulated by cool and wet weather and leads to a decline in grain quality. A low level of harvest-time seed dormancy is a major factor for PHS, which generally is a larger problem in white-grained as compared to red-grained wheat. We have in this study analyzed seed dormancy levels at the 92nd Zadok growth stage of spike development in a doubled-haploid (DH) white wheat population and associated variation for the trait with regions on the wheat genome. The phenotypic data was generated by growing the parent lines Argent (non-dormant) and W98616 (dormant) and 151 lines of the DH population in the field during 2002 and 2003, at two locations each year, followed by assessment of harvest-time seed dormancy by germination tests. A genetic map of 2681 cM was constructed for the population upon genotyping 90 DH lines using 361 SSR, 292 AFLP, 252 DArT and 10 EST markers. Single marker analysis of the 90 genotyped lines associated regions on chromosomes 1A, 2B, 3A, 4A, 5B, 6B, and 7A with seed dormancy in at least two out of the four trials. All seven putative quantitative trait loci (QTLs) were contributed by alleles of the dormant parent, W98616. The strongest QTLs positioned on chromosomes 1A, 3A, 4A and 7A were confirmed by interval mapping and markers at these loci have potential use in marker-assisted selection of PHS resistant white-grained wheat.