Paper Title
Date palm (Phoenix Dactylifera L.) Genetic Erosion in South-Eastern Algerian Groves

Abstract
Algeria is one of the richest countries in terms of date palm genetic resources with 940 cultivars (Hannachi et al. 1998). Unfortunately, only few cultivars are cultivated because of their economic value. Consequently, the genetic erosion of Algerian date palm genetic resources is continually increasing. The aim of this study was to assess the date palm genetic erosion using biodiversity indices. The data was collectedfrom the surveys conducted from 2015 to 2017 in thirteen districts of Biskra city. The results showed clearly the dominance of Deglet Noor in Ouest region and Ghars, MechDegla and common date cultivars in the Est. Also, the frequency of these latest cultivars was lower. The erosion rate varied from 18% in Biskra to 84.4% in M’choonesh, where the most important varietal richness was recorded with 36 cultivars. The Jaccard similarity index was more important between the closest oases due to their geographical proximity. In total, only seven cultivars were commonin all studied groves. Shannon-Weaver index showed a more homogeneous structure in some East districts, its value was the lowest (0.55) in Tolgadistrict where the famous Deglet Noor cultivar dominates. This study allowed the genetic erosion assessment and inform accurately about the critical status of Algerian groves biodiversity. Keywords - Date Palm, Genetic Erosion, Ecological Indexes, South-Eastern Algeria.