QTL mapping for seed germination parameters in sunflower (Helianthus annuus L.) recombinant inbred lines under salt stress

In order to assess the genetic variability for seed germination parameters under salt stress in sunflower and corresponding QTL locations, an experiment was conducted using a population of 80 recombinant inbred lines obtained from a cross between PAC2 and RHA266. The experiment was arranged under a randomized complete block design with three replications in control and saline conditions. Several germination parameters were measured including time to start germination (TSG), time to 50% germination (T50%G), time to maximum germination (TMG) and percentage of seed germination (PSG). Results showed highly significant variations among genotypes (RILs) for all traits. Salt stress had a negative effect on germination, however the significance of RIL × Condition interaction suggested that the RILs have different responses to salt stress. In this study, “1.T50%G.16.1” and “2.T50%G.17.1” QTLs (controlling T50%G under salt and control conditions, respectively) were introduced as large-effect QTLs. Moreover, “2.TSG.16.1” and “1.TSG.16.1” QTLs (controlling TSG) and also “2.PSG.12.1”, “1.PSG.12.1”, “2.PSG.12.3” and “1.PSG.12.2” QTLs (controlling PSG) were introduced as stable QTLs.