Phenotypic and molecular marker distance as a tool for prediction of heterosis and F1 performance in sunflower (Helianthus annuus L.) under well-watered and water-stressed conditions

The aim of this study was to determine phenotypic and genotypic distances in parental lines of diallel population of sunflower, and to identify correlation between both distances with F1 performance, specific combining ability (SCA) and absolutely mid-parent heterosis. The morphological distance (Euclidean distance; EDs) and genetic distance (Jaccard`s distance; JD) among five sunflower parental lines were calculated based on 12 morphological traits and 160 amplified fragment length polymorphism (AFLP) markers in either well-watered and water-stressed conditions. The un-weighted pair-group method using arithmetic average (UPGMA) clustering algorithm, based on Euclidean and Jaccard distances, classified the studied parental lines into 3 groups. In both water treatment conditions, the high values of JD were correlated with high values of ED. Correlation results revealed that both of ED and JD had significant relation with F1 performance, SCA and heterosis for some traits in both water treatment conditions. Therefore, depending upon target trait, ED and JD could effectively be utilized in order to identify heterosis. Among studied genotypes, LR25 will be regard as a permanent parent in all possible pairwise crosses with other genotypes, to achieve optimum yield in both wellwatered and water-stressed conditions.