Genetic differentiation in the medicinal plant Artemisia judaica L. populations in Saint-Catherine area, South Sinai, Egypt

Artemisia judaica is a wild medicinal plant which is exposed to serious threats due to natural drought and human impacts that justify attempts to document its genetic diversity for sustainable conservation. Genetic diversity based on variation in key morphological traits and ISSR fingerprinting was used to differentiate between A. judaica plants collected from seven different populations in South Sinai mountainous area of Saint-Catherine in Egypt. A total polymorphism percent of 64.66% was recorded and Nei's genetic diversity within the seven populations was 0.1574. In addition, the results revealed a low gene flow (Nm = 0.8344), which reflects a limited gene exchange between populations and a high degree of genetic differentiation. The principal coordinates analysis (PCA) indicated that the variation is mostly attributed to individuals' variation. The results of multiple regression analysis (MRA) showed a total of eight quantitative morphological traits associated with ISSR markers. Interestingly, the UPGMA cluster analysis of A. judaica individual plants from the seven populations showed a spatial pattern corresponds to the sites from which they were collected. A. judaica populations are found to be separated into two gene poles depending on STRUCTRE and PCA analyses. The significant genetic difference between these two gene poles might be due to possible variate evolutionary events from a single common ancestor, which originated by fragmentation of their common ancestor's range due to mountainous topography of this studied area. The results may recommend the in-situ conservation measures as the most effective and economical approach.