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    Cirsium sivasicum sp nov and C-peshmenianum sp nov (Asteraceae) and their allies from Turkey
    (Wiley, 2011) Yildiz, Bayram; Arabaci, Turan; Dirmenci, Tuncay; Celenk, Sevcan
    Two new species of Cirsium Mill. from east Anatolia (Turkey): C. sivasicum Yildiz, Arabaci & Dirmenci and C. peshmenianum Yildiz, Dirmenci & Arabaci, are described and illustrated. Both new species belong to C. sect. Epitrachys DC. (Asteraceae: Cardueae) and are closely related to C. rigidum DC., C. leuconeurum Boiss. & Hausskn. and C. karduchorum Petr. The differences between the new species and their allies are discussed and a diagnostic key is provided. A detailed description of a previously poorly known species, C. leuconeurum, is also provided. The pollen grain morphology of the new species and their allies were investigated with light and scanning electron microscopes. Based on the shape of the spines and the surface ornamentation, the pollen grains of the species were divided into 3 types: C. rigidum and C. sivasicum (type I), C. leuconeurum and C. pesmenianum (type II), C. karduchorum (type III).
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    Homoploid hybrids of Origanum (Lamiaceae) in Turkey: morphological and molecular evidence for a new hybrid
    (Taylor & Francis Ltd, 2021) Arabaci, Turan; Celenk, Sevcan; Ozcan, Taner; Martin, Esra; Yazici, Turker; Acar, Mikail; Uzel, Devrim
    In this study, three hybrids of Origanum (Lamiaceae) were examined in detail using morphological, karyological, palynological and molecular approaches. One of the three hybrids, O. x aytacii, is here described for the first time, and is compared with its putative parents, O. sipyleum and O. vulgare subsp. hirtum. In addition to morphological, karyological and palynological features, we also examined nuclear ribosomal DNA (ITS) sequences of O. x intermedium (O. onites x O. sipyleum), O. x intercedens (O. onites x O. vulgare subsp. hirtum) and their purported parental species that share the same area with the new hybrid. Pollen grains were hexacolpate and isopolar. The range of Polar/Equatorial ratio (P/E) of pollen for investigated taxa varied from 0.74 to 0.99. All investigated taxa are diploid with a chromosome number as 2n = 30. According to molecular results, O. x aytacii was the most polymorphic taxon. In addition, DNA sequences showed that O. x intercedens was more similar to O. vulgare subsp. hirtum than to O. onites, and O. x intermedium was more similar to O. onites than to O. sipyleum. Furthermore, O. onites and O. vulgare subsp. hirtum have many different ITS haplotypes, probably resulting from backcrossing with different individuals. Results obtained in this study demonstrate that hybridization has played a major role in the process of Origanum speciation.
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    Hybridization among three Cirsium (Asteraceae) species and important evidence for three new hybrids from Turkey
    (Tubitak Scientific & Technological Research Council Turkey, 2019) Dirmenci, Tuncay; Ozcan, Taner; Arabaci, Turan; Celenk, Sevcan; Ismailova, Gulnar; Yildiz, Bayram
    In this study, three new hybrids from the genus Cirsium are described for the first time. Cirsium xnezaketiae Yildiz, Dirmenci & Arabaci, C. xkelkitensis Yildiz, Arabaci & Dirmenci, and C. xerzincanicum Yildiz, Dirmenci & Arabaci are investigated in detail morphologically, palynologically, and molecularly. The hybrid individuals were detected on field trips due to their intermediate morphological characters. Their morphological properties were analyzed to compare with their parents. The pollen grain morphologies of the hybrids and their allies were investigated using light and a scanning electron microscope. The pollen grains were radially symmetrical, isopolar, trizonocolporate, and with echinate or scabrate sculpturing. The tectum is psilate/punctate, microreticulate, or ornate in sculpture. Dimorphic pollen grains were encountered in C. leucocephalum (Willd.) Spreng. subsp. leucocephalum. Two nuclear DNA regions were used to find single nucleotide polymorphisms. nrITS DNA data gave more information than nrETS data about polymorphism. In conclusion, C. xnezaketiae, C. xkelkitensis, and C. xerzincanicum exhibit some significant morphological, palynological, and molecular differences from their parents and present evidence of potential introgression hybridization. Since the hybrids live in a complex with their parents, and some parents have polymorphic loci like their putative hybrids, it can be presented as evidence for potential introgression since backcrossing may be possible among taxa.
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    An important hybrid zone: evidence for two natural homoploid hybrids among three Origanum species
    (Finnish Zoological Botanical Publishing Board, 2020) Dirmenci, Tuncay; Ozcan, Taner; Yazici, Turker; Arabaci, Turan; Celenk, Sevcan; Martin, Esra
    Based on combined results of different approaches we describe two new natural hybrids, Origanum x bilgilii Dirmenci, T. Yazici & Arabaci and O. x dumanii Dirmenci, Arabaci & T. Yazici from southern Turkey (Antalya). They have a common parent, Origanum saccatum. Morphology and pollen micromorphology of the collected plants were studied, and a comparison of one nuclear (nrITS) and one chloroplast (rpl32) DNA marker was performed. The ploidy level of the two hybrids was established by chromosome counts. Both hybrids have some morphological characters in the leaves. bracts, calyces and corollas that are intermediate between those of their parents. Surface sculpturing and pollen grain size and shape of the hybrids vary and differ to a certain degree from those of the parental species. Heterozygous loci were detected in nrITS sequences of both O. x bilgilii and O. x dumanii, while rpl32 sequences were uninformative. Both hybrids and their parents have the same chromosome number of 2n = 30.