Comparison of karyotype and rDNA-distribution in somatic chromosomes of Bowenia species (Stangeriaceae, Cycadales)

G. Kokubugata, K. Kondo, G. W. Wilson, L. M. Randall, A. van der Schans and D. K. Morris

Abstract

Somatic chromosomes at mitotic metaphase of Bowenia serrulata, B. spectabilis and B. sp. ‘Tinaroo’ is investigated by the standard aceto-orcein staining method and the fluorescent in situ hybridisation method (FISH) with ribosomal DNA (rDNA) probe. Bowenia serrulata, B. spectabilis and B. sp. ‘Tinaroo’ each have a chromosome number of 2n = 18. The karyotype of B. serrulata exhibits 10 median-centromeric chromosomes, while B. spectabilis and B. sp. ‘Tinaroo’ exhibit eight median-centromeric chromosomes. By using FISH, B. serrulata, B. spectabilis and B. sp. ‘Tinaroo’ show a hybridisation signal on the satellite of the short arm of two submedian-centromeric chromosomes. However, the other hybridisation signal pattern is different among B. serrulata, B. spectabilis and B. sp. ‘Tinaroo’.

Australian Systematic Botany 13(1) 15 - 20  doi:10.1071/SB98028