Specific Rapd Markers of Imperata Cylindrica Populations in Taiwan

Imperata cylindrical L. Beauv, a common C4 grass, is widely distributed in various habitats in Taiwan. Among 55 populations in various habitats, six sites were selected for the study. These sites are namely, Chuwei (an estuary man-grove forest area with high salinity), Sarlun (in coastal saline area), Kengting (at south tip with dry season in wither), Penghu (an islet about 100 km from west coast and is dry in most seasons), and Nankang and Hoshe (both in in-land with mild weather as control sites). The total DNA was extracted from leaves of I. cylindrical collected from the six sites. The DNA was then analyzed by means of a random amplified polymorphic DNA (RAPD) technique. Fourty primers were used for the RAPD anlysis, and only four primers, namely OPA-16, OPA-20, OPV-03, and OPV-13, were successful in obtaining genetic mark-ers for the populations at the sites. Five markers, namely A162, A163, V32, V33, and V131 were obtained. Of them, markers 162 and 163 were generated from primer OPA-16 was found in populations of Nankang, Penghu and Sarlum; however, it was very specific to population Penghu. Markers A163 was only found in population Sarlun. Markers V32 and V33 were generated from primer OPV-03; the former was present all populations except population Chuwei, while later was only found in the Chuwei pop-ulation. Marker V131 was generated from primer OPV-13 and marker A163 was from OPA-16. The marker V131 was specific to the Chuwei population. Regarding the length of the markers, marker V32 has 1198 bp, marker V33 possesses 1173 bp, and marker V131 reveals 1166 bp. Comparing the DNA se-quence of markers V32 and V33, they exhibited 64% homology. All of these population-specific markers are repetitive sequences as revealed from the RFLP analysis. It is concluded that the aforementioned markers are specific to either inter-or intra-specific population of I. cylindrical. It is also suggested that the unique ecotype formation of Chuwei population is a result of adapta-tion to stressful environment, such as anaerobic and saline habitat.