Effect of geographic range discontinuity on taxonomic differentiation of Abies cilicica

Abstract

Three populations of Abies cilicica subsp. isaurica and four of A. cilicica subsp. cilicica were analyzed using 35 morphological and anatomical needle characters with the implementation of multivariate statistical methods to verify the differences between subspecies. Moreover, the possible geographic differentiation of A. cilicica subsp. cilicica populations from the East Taurus and Lebanon Mountains was examined. Abies cilicica subsp. isaurica has been distinguished from A. cilicica subsp. cilicica by its glabrous young shoots and resinous buds. We detected that needles of A. cilicica subsp. isaurica are longer, broader and thicker, with a higher number of stomata rows, and larger cells of the epidermis, hypodermis and endodermis than A. cilicica subsp. cilicica. Additionally, A. cilicica subsp. isaurica needles have frequently rounded to obtuse-acute apex and resinous canals positioned more centrally inside the mesophyll than needles of A. cilicica subsp. cilicica. This indicates that a set of most of the tested needle characters can be used to distinguish the subspecies; however, any of characters enable that when used separately. Morphological and anatomical distinctiveness between these two taxa justify their recognition at the subspecies rank. Additionally, the populations of A. cilicica subsp. cilicica from the East Taurus and Lebanon are morphologically different. This geographic differentiation of populations is congruent with results provided by genetic analyses of nuclear microsatellites markers (nSSR).

Keywords

• biogeography
• biometrics
• Cilician fir
• East Mediterranean region
• multivariate analyses
• plant diversity
• plant variation