Hybridization among three Cirsium (Asteraceae) species and important evidence for three new hybrids from Turkey

Abstract

In this study, three new hybrids from the genus Cirsium are described for the first time. Cirsium ×nezaketiae Yıldız, Dirmenci& Arabacı, C. ×kelkitensis Yıldız, Arabacı & Dirmenci, and C. ×erzincanicum Yıldız, Dirmenci & Arabacı are investigated in detailmorphologically, palynologically, and molecularly. The hybrid individuals were detected on field trips due to their intermediatemorphological characters. Their morphological properties were analyzed to compare with their parents. The pollen grain morphologiesof the hybrids and their allies were investigated using light and a scanning electron microscope. The pollen grains were radiallysymmetrical, 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. Twonuclear DNA regions were used to find single nucleotide polymorphisms. nrITS DNA data gave more information than nrETS dataabout polymorphism. In conclusion, C. ×nezaketiae, C. ×kelkitensis, and C. ×erzincanicum exhibit some significant morphological,palynological, and molecular differences from their parents and present evidence of potential introgression hybridization. Since thehybrids live in a complex with their parents, and some parents have polymorphic loci like their putative hybrids, it can be presented asevidence for potential introgression since backcrossing may be possible among taxa.