Morpho-agronomic and molecular characterization of snap bean diversity panel

Considering the importance of characterizing germplasm banks for their conservation and use in breeding programs and the commercial and nutritional potential of snap beans, the present study aimed to characterize the genetic diversity of snap bean accessions from the germplasm bank of IDR-Parana through morpho-agronomic descriptors and molecular markers. A total of 102 snap bean accessions were evaluated, including 60 and 42 accessions of indeterminate and determinate growth habits, respectively. Sixty descriptors were used for morpho-agronomic characterization, which were evaluated in the wet season harvests of 2017 and 2018 using a randomized block design with three repetitions. Molecular characterization was performed using amplified fragment length polymorphism markers (AFLP) with four primer combinations. There was a wide variability among the snap bean accessions and a positive correlation between morpho-agronomic and molecular descriptors. The formation of two large groups of snap bean was observed and growth habit was strongly associated with gene pool, with evidence of high diversity among the accessions of the indeterminate growth habit. The descriptors that allowed high discrimination of the accessions were those that related to crop yield and cycle. The genetically divergent accessions with desirable agronomic characteristics may be used in crosses to initiate a breeding program.