Genetic diversity of local Tunisian squash seeds

Biodiversity is essentially composed of genetic diversity. Indeed, it is necessary to maintain genetic resources to ensure the evolution of natural plant and animal populations. Currently and with the changes in environmental conditions, it is necessary to study the adaptation and resistance of local species, especially in cucurbits, which are important in the human diet. The main objective of this study is to characterize the genetic variability of Tunisian Cucurbita maxima populations to maintain local accessions. An in-situ evaluation of this squash collection resulted in a mapping and highlighted a great morphological diversity between fruits and seeds from major production areas. Agro-morphological study of collected squash, through UPOV and IPGRI descriptors, revealed a high polymorphism. The total phenol content and antioxidant capacity of squash seeds were high. Genetic diversity measured from RAPD, ISSR and SRAP markers allowed the development of a phylogenic tree using UPGMA and STRUCTURE techniques.