Functional Genomic Approaches to Identify a Major Dormancy Gene in Wheat

Increasing grain dormancy is an important goal for wheat breeders globally in order to reduce the risk of preharvest sprouting in modern bread wheat (Triticum aestivum L.). Grain dormancy is a complex trait influenced by environmental factors making selection difficult and consequently the identification of perfect molecular markers would greatly increase selection efficiency. A Multi-parent Advanced Generation Inter-Cross (MAGIC) population has been successfully used for mapping dormancy QTLs, including a major QTL located on the long arm of 4AL. Here, we present an update on our work towards cloning this important QTL by using a four-parent MAGIC population and by developing sets of Heterogeneous Inbred Families (HIFs) segregating for that QTL. RNA samples were taken from five HIFs during grain development and after deep-sequencing and pool-analysis of lines with and without the QTL several candidate genes were identified as polymorphic or as differentially expressed and mapped to the 4AL chromosome. Functional analysis using transgenic wheat has identified a strong gene candidate that underlies the QTL.