Mapping of a QTL in Chromosome 3B for Grain Dormancy in White-Grained Wheat Population

Abstract

White-grained wheat is usually more susceptible to preharvest sprouting than red-grained wheat. Identification of QTLs affecting grain dormancy is one of the promising ways of developing PHS tolerant white grained-wheat. A white-grained recombinant inbred line (RIL) population was developed from a cross between highly dormant Japanese red-grained wheat cultivar, 'Zenkoujikomugi' ('Zen'), and a low dormant white-grained wheat cultivar 'Spica'. The 3B chromosome was assessed with SSR and EST markers covering most of the chromosomal areas. A highly significant quantitative trait locus (QTL) associated with grain dormancy on chromosome 3B was identified in this cross and the allele contributed to higher dormancy was derived from 'Zen'. Linkage map of 3B short arm was developed showing the location of the QTL linked with Xwocs207 marker. The results of the t -test revealed that the QTL was significant in 5 environments in the field and 3 environments in the glasshouse. This QTL was detected only in the white-grained RIL population and it was not detected if the phenotypic variation of the population was affected by major red color genes. Mapping of the QTL with QGENE also proved that this QTL, located close to the centromere region of 3B, can be a major influential factor for the total dormancy variation of this cross in the field. Keywords : grain dormancy; pre-harvest sprouting; QTLs; SSR markers; white-grained wheat DOI: 10.4038/jfa.v1i2.1794 Journal of Food and Agriculture Vol.1(2) 2008 pp.1-10