Classification of wheat genotypes by yield and densities of grain zinc and iron using cluster analysis

Cluster analysis can be a powerful tool in aiding efficient genotype selection in multiple-trait crop breeding. In order to fight human mineral malnutrition by biofortification, breeding for high densities of grain Zn and Fe has become a new target in recent years. In the same time yields should not be compromised. We used cluster analysis to classify Iranian wheat genotypes into different groups based on response to Zn deficiency and grain Zn and Fe concentration. Thirty spring wheat genotypes were grown at different experimental sites (Isfahan and Karaj) for two consecutive years. Zinc was soil-applied at two different rates (0 and 40 kg Zn ha− 1 as ZnSO4⋅ 7H2O) as Zn sulfate prior to planting. Using a stress tolerance index (STI) to quantify the response of the genotypes to Zn deficiency spring wheat genotypes were identified in four clusters in Isfahan and in five clusters in Karaj. At Isfahan high grain Zn concentrations were correlated with high grain Fe concentrations, while at Karaj high grain Fe concentrations were associated with high tolerance for Zn deficiency. The results demonstrate that cluster analysis can be a valuable method to classify wheat genotypes for breeding purposes, accounting for interactions of traits with location.

► Using cluster analysis, wheat genotypes were classified into 3-5 groups.
► High-yield genotypes with high grain Zn and Fe were classified.
► The location had significant impact on classification of wheat genotypes.
► Cluster analysis is a useful tool to classify genotypes for biofortification aims.