Identification of a Homologue of DOG 1 Within a Major QTL Region of Seed Dormancy in Groundnut (Arachis hypogaea L.)

Groundnut (Arachis hypogaea L.), an important oilseed and food crop, is encountered by end season rains leading to in situ germination. Seed dormancy of 2-3 weeks is essential to escape this problem. In this study, a major QTL (qDORM_A04_MET) for seed dormancy was identified by mapping with MITE and SSR markers using a recombinant inbred line population derived from non-dormant parent (TG 51) and dormant parent (TG 22). This QTL explained 12% phenotypic variation due to seed dormancy in the RIL population and covered 46 Mb map-interval in chromosome A04. While, QTL-Seq has revealed a broader region of Arahy.04 that has significant association with dormancy phenotype in terms of ΔSNP index in this genomic region. This broader region of A04 has several significant InDels, which were used to design PCR based markers. These markers were used for re-mapping of dormancy QTL and identified a relatively smaller genomic region with significant QTL detection. Sequence comparison and gene annotation analysis of this new QTL version qDORM_A04_MET revealed six putative genes related to seed dormancy. Of them, a homologue of ‘Delay Of Germination 1 (DOG 1) was found upregulated commonly among three near isogenic dormant lines compared to their respective non-dormant counterpart. Thus, the present report describes identification of DOG1 homologue in Arahy.04 towards its putative role in seed dormancy using both genomics, transcriptomics and conventional genetic mapping approach.