Phenotypic and molecular diversity in a collection of ‘Pomodoro di Sorrento’ Italian tomato landrace

The ‘Pomodoro di Sorrento’, originating from Southern Italy, represents one of the most important andremunerative Italian tomato landraces for “fresh market”. Despite its outstanding organoleptic and nutri-tional qualities scanty information still exists on the structural variation of this traditional tomato. Herewe report the evaluation of ten accessions of the ‘Pomodoro di Sorrento’ tomato at phenotypic and molec-ular levels in order to provide a basis to unequivocally distinguish them from those belonging to the othermost famous similar landraces grown in Italy. Morphological characterization based on 13 descriptorshighlighted the presence of a significant level of variation for puffiness, green color and green shoulderof unripe fruits, allowing distinguishing two ‘Sorrento’ morphotypes. Genome-wide SNP genotyping wascarried out using the ILLUMINA Infinium tomato array and revealed a genetically well defined structureof the ‘Sorrento’ landrace with respect to the other multilocular landraces most widespread in Italy. Inparticular, 1450 SNPs resulted polymorphic among 20 tested genotypes, and one clearly distinguishes the‘Sorrento’ from other similar landraces. Finally, resistance assay to Verticillium wilt allowed the identifi-cation of promising ‘Sorrento’ accessions. Interestingly two markers localized into the Ve2 gene showeda strong association with the resistance/susceptibility trait. Taken as whole, our results provide a descrip-tion of ‘Pomodoro di Sorrento’ landrace diversity, which provide useful information for its utilization inbreeding programs as well as for its direct use in quality markets.