Sexual reproduction of interspecific hybrids between Cyclamen persicum MILL. and Cyclamen purpurascens MILL.

Interspecific crosses between the diploid C. persicum MILL. 'Reinwei ss' (2 n = 2x = 48) and C. purpurascens MILL. (2n = 2x = 34) were carried our in 1 993 and hybrids were obtained using ovary culture (EWALD 1996). Sexual plan t reproduction of these interspecific hybrids (2n = 2x = 41 and 2n = 4x = 8 2) has been studied. The analysis of the microspores of interspecific hybrids revealed abnormali ties in early stages of meiosis. In the anaphase I a high number of univale nts was observed. Pairing between some chromosomes of C. persicum and C. pu rpurascens is assumed to be: due to homologous regions. The presence of sev eral univalents completely hindered in some cases the separation of chromos omes, so that cell division did not take place. These microspores showed 1n = 2x = 41 chromosomes, and the resulting pollen grains were viable, normal shaped and of the same size as those of spontaneous occurring amphidiploid hybrid plants (2n = 4x = 82). Pollen viability ranged after staining with fluorescein diacetate between 0 .3 % and 34.0 % in diploid, and between 9.7 % and 54.0 % in amphidiploid hy brids. The growth of pollen tubes in the tissue of the pistils was normal i n all cross combination. But only in the combination tetraploid C. persicum x amphidiploid hybrid and reciprocal low frequences of micropylar penetrat ion were observed. Sexual reproduction and further cross breeding with C. p ersicum were only successfull when tetraploid plants were used. Spontaneous amphidiploid hybrids developed seeds as well as after selfing and in cross combinations with tetraploid C. persicum. From the seeds of the cross comb ination tetraploid C. persicum x amyhidiploid hybrids plants were grown til l flowering which were true to C. persicum or intermediary.