A Core Set of Snap Bean Genotypes Established by Phenotyping a Large Panel Collected in Europe

Snap beans are a group of bean cultivars grown for their edible immature pods. Theobjective of this work was to characterize the diversity of pod phenotypes in a snap bean panel (SBP),comprising 311 lines collected in Europe, and establish a core set (Core-SBP) with the maximumdiversity of pod phenotypes. Phenotyping of the SBP was carried out over two seasons based on14 quantitative pod dimension traits along with three qualitative traits: pod color, seed coat color,and growth habit. Phenotypes were grouped into 54 classes using a hierarchical method, and aCore-SBP with one line per phenotype class was established. A further field-based evaluation ofthe Core-SBP revealed higher diversity index values than those obtained for the SBP. The Core-SBPwas also genotyped using 24 breeder-friendly DNA markers tagging 21 genomic regions previouslyassociated with pod trait control. Significant marker-trait associations were found for 11 of the21 analyzed regions as well as the locus fin. The established Core-SBP was a first attempt to classifysnap bean cultivars based on pod morphology and constituted a valuable source of characteristics forfuture breeding programs and genetic analysis.