Assessment of Heterosis Based on Genetic Distance Estimated Using SNP in Common Wheat

Abstract

This study assessed the genetic distance (GD) between parental genotypes using single nucleotide polymorphism (SNP) DNA markers and evaluated the correlation between GD and heterosis in common wheat. We examined the performance of parents and hybrids in a field experiment conducted in a randomized block design at a Shihezi location with three replications. Different traits such as the height of the parents and the F1 generation, number of harvested ears, number of grains per panicle, grain weight per panicle, 1000-grain weight, and grain yield were examined. Genotyping using a wheat 90K SNP chip determined the GD between the parents and analyzed the relationship between GD and heterotic performance of hybrids in wheat. Cluster analysis based on GD estimated using SNP chips divided the 20 elite parents into five groups which were almost consistent with the parental pedigree. Correlation analysis showed a significant association between GD and mid-parent heterosis (MPH) of 1000-grain weight. However, GD and high-parent heterosis (HPH) of 1000-grain weight showed no significant correlation. There was a weak correlation between GD and with spikelet number, harvested spikes, and yield at MPH or HPH. Hence, SNP analysis may be utilized in allocating wheat parents to heterotic groups. However, the correlation between SNP-based GD and hybrid performance still remains unclear.