Cytotaxonomy of endangered species Orobanche filicicola in Korea and its closely related species, Orobanche coerulescens (Orobanchaceae) (I)

The genus Orobanche is mainly distributed in the northern hemisphere and consists of about 170 species. The present study focuses on a cytological study of Korean endangered species Orobanche filicicola and morphologically similar species Orobanche coerulescens and its morphotype, which was previously referred to as O. coerulescens f. alba but was taxonomically treated as a synonym of O. coerulescens. Chromosome numbers of 13 individuals in six populations of two Korean Orobanche taxa (O. coerulescens and O. filicicola) and morphotype of O. coerulescens were examined to understand the karyotype diversity. A chromosome number of 2n = 2x = 38 was uniformly observed for all the Orobanche taxa in Korea despite individuals of two different color types (typical purple and whitish yellow) being included. The karyotypes of O. filicicola were metacentric to submetacentric, and the length of chromosomes ranged from 2.08 to 4.74 mu m, resulting in a haploid karyotype length of 60.92 mu m. Investigations of meiotic configuration of O. filicicola, O. coerulescens, and its morphotype were constantly stable. In those species, all homologous chromosome pairs have formed regular bivalents as previously documented in other species of the genus Orobanche. (C) 2020 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing Services by Elsevier.