The karyotypes of seven species of Chrysanthemum sensu lato collected in Russia were documented for the first time: Chrysanthemum maximowiczii V. Komarov, 2n=54=36m+16sm+2st; C. sinuatum Ledeb., 2n=18=14m+2sm+2st; C. zawadskii Hebrich, 2n=54=34m+16sm+4st; Tanacetum achilleifolium (M. Bieb.) Schuttz-Bip., 2n=18=14m+4sm; T. boreale Fisch. ex DC., 2n=18=16m+2sm; T. kittaryanum (C. A. Mey.) Tzvel., 2n=36=26m+10sm; T. uralense (H. Kraschen.) Tzvel., 2n=18=13m+5sm. This result supported the assumption that C. sinuatum could hybridize naturally with Brachanthemum krylovii (2n=18, diploid) to produce the hybrid as Brachanthemum baranovii (Krasch. et Poljak) Krasch. The karyotypes of T. vulgare and T. boreale were different from each other. Fluorescence in situ hybridization (FISH) experiment using 45S rDNA probe pTa71 was applied to nine species of Chrysanthemum sensu lato. The numbers of 45S rDNA signals in C. crassum, C. ornatum, C. sinuatum, C. zawadskii, T. kittaryanum and T. uralense were reported here for the first time. Fourteen 45S rDNA signals were found in C. crassum (2n=90, decaploid), C. zawadskii (2n=54, hexaploid) and T. uralense (2n=18, diploid). Twelve signals were found in C. ornatum (2n=54, hexaploid). Ten signals were found in T. kittaryanum (2n=36, tetraploid). Eight signals were observed in T. parthenium. Six signals were observed in C. sinuatum (2n=18, diploid) and T. vulgare (2n=18, diploid). The number of hybridization signals obtained for T. vulgare verified Honda et al. (1997). Frequency of signal number/chromosome complement was calculated. Tanacetum uralense show the highest frequency of 77.7%, T. vulgare and C. sinuatum showed the frequency of 33.3%, T. kittaryanum showed the frequency of 27.8%, D. zawadskii showed the frequency of 25.9%, T. parthenium and C. ornatum showed the frequency of 22.2%, and C. crassum showed the frequency of 15.5%.
2006 International Society of Chromosome Botany