PHYTOCHEMICAL AND MOLECULAR ANALYSIS OF SOME MEDICINAL PLANTS OF LABIATAE FAMILY GROWING AT DIFFERENT ALTITUDES ON SAINT KATHERINE MOUNTAIN,SOUTH SINAI, EGYPT

Abstract

The present investigation was carried out to study the effect of altitudinal gradients on genetic and phytochemicals contents of three medicinal plant species belong to family Labiatae (Nepeta septemcrenata, Ballota undulata and Teucrium polium) in Saint Katherine Mountain under natural conditions. All analyses were carried out through three different altitudes viz., 1800 m a.s.l., 2200 m a.s.l. and 2600 m a.s.l. for the three species. Phytochemicals such as phenols, tannins, alkaloids, flavonoids and saponins were present in the methanolic extracts of aerial parts of three studied plant species but their quantity varied significantly across the different altitudes. The different species under study showed different values of total flavonoids, total phenolic acids, total saponins, total alkaloids and total tannins under the same environmental conditions. Meanwhile the same species exhibited different values of these metabolites under different elevation ranks. In general, total flavonoids and total phenolic acids were strongly increased with the increase of elevation from 1800 m a.s.l. until 2600 m a.s.l., however total saponins, total alkaloids and total tannins were slightly changed. The results are encouraging but scientific validation is necessary before being put into practice. RAPD and ISSR markers were successfully applied to assess the genetic diversity of the three medicinal plant species at the three different altitudes under natural conditions. Each of the five RAPD primers and the five ISSR primers used for analysis amplified different number of fragments. Each of the ten primers yielded from 5 to 12 DNA fragments whose molecular size ranged from approximately 200 to 1890 bp. The total number of amplified was 76 bands with an average of 7.6 fragments / primer and the total number of polymorphic fragments was 64, thus, representing a level of polymorphism of 84%. The highest number of amplified fragments (60) after using all the primers was detected in N. septemcrenata at 2200 m a.s.l with an average of 6 fragments per primer while the lowest number (35) was detected in T. polium at 1800 m a.s.l with an average of 3.5 fragments/primer. The highest similarity value (0.897) was found between B. undulate at 1800 m a.s.l and at 2200 m a.s.l while the lowest value (0.420) was found between B. undulate at 1800 m a.s.l and T. polium at 2200 m a.s.l. The dendrogram separated the three medicinal plant species into two clusters. First cluster included B. undulate and T. polium while second cluster included N. septemcrenata. The dendrogram separated the three different altitudes into two clusters. First cluster included 1800 m a.s.l and 2200 m a.s.l while second cluster included 2600 m a.s.l. Genetic polymorphism, the qualitative and quantitative phytochemical among the species are related to an altitudinal gradient. Assessing of genetic and phytochemical content of plants at varying altitudes can help to select elite genotype and reflect the best suited altitude for commercial cultivation of the species as these phytochemicals are considered as the basis for their medicinal activity.