Gene-ecological and phytochemical studies on genus Cyperus in Egypt

Abstract

Significant morphological and chemical variations have been revealed in Cyperus rotundus populations in Egypt. Correlations were calculated for several pairs of morphological quantitative characters and the constituents of volatile oil in the tubers of this species. The cluster analysis of populations based on morphological criteria, on volatile oil components and their combination distinguished some populations of C. rotundus indicating the presence of genetic variation between populations of this species in Egypt. the determination of volatile oil content indicated that tubers of plants growing in Esna south of Egypt have the highest amount of oil, while those of plants from El-Fayium and Zagazig contain the lowest proportion. GCIMS analysis of the oil revealed a total of 39 components. The highest number (38 compounds) were found in the oil of plants growing in Geziret El-Dahab, Giza, while the lowest number (32 compounds) was detected in plants from Nagh Hammadi (Qena). The three tricyclic sesquiterpenes; cyperene, u-cyperone and cyperotundone are the major components of the oil of C. rotundus in the majority of populations. Other sesquiterpenes were also identified such as u-copaene, P-selinen, y-cadinene, calamenene and caryophyllene oxide. In addition three monoterpenes were identified; these are a-pinene, p-pinene and D-limonene. Phytochemical screenmg of C. rotundus and C.'. esculentus showed that the underground parts (tubers) of the two species contain most of the secondary products. The cytotoxicity of water extracts of these parts was examined using the Allium cepa root tip assay test. The extract of both species inhibited mitosis and induced a number of chromosomal abnormalities. However root tip cells exposed to low concentrations for short periods fully recovered after 24 hours post treatment in water. High doses of the two extracts were lethal to the root cells: