Cytological and Cytoembryological Studies on Paeonia tenuifolia L.

Authors: Feruzan DANE

Abstract: The cytology and cytoembryology of Paeonia tenuifolia L. (Paeoniaceae) at Ortakçi Village near Edirne during the years 1989-1991 are considered in this study. Chromosome counts were done on adventive roots, and the results were found to be 2n=10. In the karyotype, 3 median (M), 1 submedian (SM) and 1 subterminal (ST) chromosome pairs were found, in two of which SAT-chromosomes were detected. The anther wall of P. tenuifolia consists of an epidermis , a 1-3 layered endothecium, 1-2 middle layers and a 1-2 layered tapetum. In the secretory tapetum, normal mitosis and the ÒstickyÓ type of division were observed. In most microspore mother cells, the course of meiosis is regular. In some cells irregularities were observed, including chromosome bridges, univalent and fragments. Microspore tetrads are isobilateral and tetrahedral, polen grains are tricalporate and are shed at the 2 celled stage. In rare cases, polyspory and multinucleate pollen grains were observed. The course of meiosis in the megaspore mother cell is regular. The ovules are anatrapous, bitegmic and crassinucleate. The female archesporium is multicelled. The female gametophyte formed by the functioning chalazal megaspore is monosporic, of the Polygonum type, in the mature embryo sac, the egg apparatus, the normal appearence of the secondary nucleus and of the antipodal cells. The occurence of double and triple embryo sacs due to the further development of chalazal megaspores of double and triple tetrads was observed.

Keywords: Paeonia tenuifolia L. Microsporogenesis, Megasporogenesis, LM.