Insight into palynological characteristics of Vinca species in Turkey and their taxonomic relationship

Abstract

The aim of this research is the palynological characterisation of all Vinca species naturally grown in Turkey. In this context, six Vinca (Apocynaceae) taxa from Turkey were investigated – V. herbacea Waldst & Kit., V. ispartensis Koyuncu & Ekşi, V. minor L., V. major subsp. major L., V. major subsp. hirsuta (Boiss.) Steam, and V. soneri Koyuncu – by a palynological approach, and palynological characters of the more closely related taxa (especially two new species and subspecies) were defined. Thus, pollen structures of the six taxa and their systematical relations could be discussed. The pollen type of the studied taxa was determined to be colpate and the sculpture psilate. The results confirm that palynological characters show minor differences between the investigated taxa of the genus. Nevertheless, these features can be used to discriminate among the taxa. PAST-multivar-cluster and principal component analysis were applied to the obtained data to compare the palynological characters of the six taxa and prove the similarities among their pollen. The results shed light on the relationship between two new Vinca species (V. soneri Koyuncu, V. ispartensis Koyuncu & Ekşi) and their closest taxa (V. herbacea). The statistical results determined the simmilarities of morphologically closer taxa (V. herbacea, V. ispartensis, V. soneri) and indicate that V. herbacea and V. ispartensis are much closer to each other compare to V. soneri, with regard to the palynological features. Also, the two subspecies (V. major subsp. major and V. major subsp. hirsuta) were observed to be most closely related to each other. In conclusion, with a few exceptional states, the palynological findings support the morphological classification. As the results demonstrate, palynological parameters can be helpful for taxonomical classification of plant taxa.