Karyomorphology and nuclear DNA content of sixteen Ophrys L. taxa from Turkey

Abstract

Karyotypes in 16 representative taxa of the Ophrys genus are compared, based on Feulgen-stained somatic metaphase chromosomes. The karyotypes of O. omegaifera subsp. israelitica, O. ulupinara, O. lycia, O. argolica subsp. lucis, O. argolica subsp. lesbis, O. climacis and O. reinholdii subsp. reinholdii are described for the first time. Karyological analyses indicate relationships among the species with respect to their asymmetry indices. All Ophrys taxa studied were diploid with 2n=2x=36 chromosomes. One B chromosome has been detected among the chromosomes of O. argolica subsp. lucis. All karyotypes are symmetrical, consisting of metacentric and submetacentric chromosomes. The longest chromosomes of all the investigated specimens contain a secondary constriction. It is determined that there is a correlation between the total number of chromosomes having secondary constrictions and the evolutionary development order of the taxa. Based on nuclear DNA content, analysis was carried out by flow cytometer using propodium iodide as fluorochrome, 2C nuclear DNA content of 16 Ophrys species varying between 20.80pg (O. argolica subsp. lucis) and 23.11pg (O. omegaifera subsp. israelitica). Karyotype asymmetry relationships are discussed according to the bidimensional scatter plots of A(1)-A(2), CVCL-CVCI, CVCL-M-CA and CVCI-M-CA.