Morphologic and cytotaxonomic investigations of Tripleurospermum Sch. Bip. (Asteraceae) species in the East Balck Sea region

SUMMARY Morphologic and Cytotaxonomic Investigations of Tripleurospermum Sch. Bip. (Asteraceae) Species in the East Black Sea Region In this study, distributed in the East Black Sea Region, 14 Tripleurospermum taxa belonging to 19 populations were investigated morphologically and karyologically. Plant materials were collected from Trabzon, Rize, Artvin and Gümüşhane in the periods of their vegetation between 2000 - 2002. Morphological studies were carried out from herbarium specimens, and karyological investigations were performed on permanent slides prepared from actively growing root tips. Karyological data obtained from chromosome measurements were analysed by using numeric analyses. The taxa which are closely related with each other were compared with karyological characteristics. As a result of morphological investigations, a new key was prepared for Tripleurospermum species distributed in the study region; one new record (T. subnivale) for the flora of Turkey and two new records (T. rosellum var. album and T. parviflorum) for the flora of study region were added. The chromosome numbers of the taxa studied have been determined as 2n = 2x = 18 (T. caucasicum, T. melanolepis, T. elongatum, T. parviflorum, T. transcaucasicum and T. decipiens), 2n = 4x = 36 (T. caucasicum, T. oreades var. oreades, T. oreades var. tchihatchewii, T. rosellum var. album, T. sevanense, T. callosum and T. monticolum) and 2n = 5x = 42 - 48 (T. subnivale). A new ploidy level (5x; pentaploid) has been found for the genus Tripleurospermum. No variation in the basic chromosome number was showed in the genus. It was determined that the karyotypes of the taxa consist of median, submedian and subterminal centromered chromosomes with karyotype analyses. It was detected that diploid and polyploid species composed of different clusters in the dendrogram and species which are morphologically similar to each other were generally in the same clusters. Additionally, some karyologic variations were determined among different populations of the same species. Key Words: Tripleurospermum, Asteraceae, Cytotaxonomy, Chromosome Number Karyology, Polyploids Cluster Analysis, New Record VI