Study of the karyotypes of saffron (C. sativus L.) and its close wild relatives with application of routine and banding techniques

Karyotypes of saffron, Crocus sativus L., and its close relatives C cartwrightianus, C. hadriaticus, C. oreocreticus, also C. sativus ' Kashmerianus' and 5 wild species collected from different parts from Iran were studied. Generally are revealed new features in the structure of karyotypes at all investigated species and forms, which are very valuable from the view point of evolution and systematics of the taxons under study. These data certainly will play certain role in final analyses of many problems of an origin of species C. sativus L., remaining unclear on the present time. Application of C-banding technique revealed heterochromatin segments. The sharpest heterochromatin was on telomere of the short arm of chromosome type (triplet) 3 and on proximal part of the long arm of chromosome type 1; a sharp heterochromatin on telomere of the short arms of chromosome types 1, 4 and on the satellites, and a weak heterochromatin on a centromeric region all of 24 chromosomes. Chromosome type 5(1) had a heterochromatin that was a little stronger on the centromeric and, considerably weaker on telomeric regions comparing to those of chromosome type 4. Was made, however, one significant addition to the specified structure, namely, on the chromosome 2, being satellited, the rather large segment of heterochromatin, adjacent with a zone of centromere, is found at the large arm. Karyotypes of the diploid species and of the triploid variety 'Kashmerianus' were characterized. The karyotype of 'Kashmerianus' completely repeats pattern of that of usual saffron, but there is one difference as presence in 'Kashmerianus' of satellites of the identical sizes at all three homologs of chromosome number 2. Diploid species, so-called close relatives of saffron, have karyotypes, basically similar to those at C. sativus L., however between them and saffron there are also basic differences. In the report these similarities and differences in aspect of evolution are in details analyzed. It is necessary to ascertain especially close similarity of the karyotypes of C. sativus and C. cartwrightianus and in not of a smaller degree, C. oreocreticus. The karyotype of species C. hadriaticus has more differences from the karyotype of saffron. At C. hadriaticus were registered differences regarding existence or absence of the heteromorphic chromosomes between various plants of the same species. Among species collected from Iran, C. michelsonii was the closest to C. sativa L. A new cytotype C. pallasii subsp. hausknechtii with 2n= 2x = 12 chromosomes from west of Iran was reported for the first time. Aneuploidy and univalent shift was reported in C. speciosus for the first time.