Characterization of Tunisian genetic resources of Watermelon (Citrullus lanatus)

Abstract

In Tunisia, watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is largely consumed in summer as a fresh fruit. This cucurbit is cultivated in various areas in the country. The landraces are a very important source of genetic diversity, constituting an important genetic resource for plant breeders. The aim of the present study was to collect and characterize fruit diversity of watermelon landraces collected from local farmers from Monastir and Sousse areas of Tunisia. The landraces were categorized for 20 variables of fruit features according to UPOV descriptors for watermelon. Also, these landraces were screened by artificial inoculation for their resistance to Fusarium oxysporun f.sp niveum (FON) races 0 and 2 to identify sources of resistance to Fusarium wilt. Significant differences were found among accessions for the quantitative traits recorded, revealing a large diversity. The evaluated watermelon landraces expressed a wide range of phenotypes including fruit size, flesh color, rind pattern, FON disease resistance and sweetness.