Morphological Characterization of Some Local Varieties of Fig (Ficus carica L.) Cultivated in Southern Italy

Abstract

Figs (Ficus carica L.) are ancient fruits of the Mediterranean basin. In Southern Italy, they are particularly important in the traditional course of local cuisine. In Southern Italy, fig trees are rarely cultivated in specialized orchards but are present in association with other fruit trees (for example, olive, almond, pear, pomegranate, and grapevine). These mixed orchards are particularly important in the traditional agroecosystems of the south of Italy. This study reports preliminary results on the local fig variety’s leaf morphological characterization, aiming to elucidate the presence of synonymousness or homonymy for in situ and ex situ conservation and further exploitation. A field survey was carried out during the summer of 2018 in some areas of the Basilicata district. Thirty local putative varieties were collected, and each of them was identified by GPS coordinates and recorded photographically. Moreover, they were cataloged with the name of the Municipality of origin, year, details of growing location (main crop, mixed orchard, gardens, and single plants), approximate age, and the local name supplied by the donor. All relevant information was included in the accession code. Leaf samples were collected from each accession from medium-length shoots. A digital image of each leaf sample was captured using a digital camera. Leaf morphometric traits were recorded using ImageJ and statistically analyzed using the software PAST 4.11 to discriminate among fig accessions. The multivariate morphometric approach applied correctly classified more than 90% of the leaves and helped to discriminate among accession. Moreover, linear discriminant analysis helped to recognize the presence of different synonymousness and homonymy of different accessions. The results revealed that measured leaf morphometric aided by image analysis could be a simple and inexpensive accessions classification tool.