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Chromosome Differentiation in Drosera, Subgenus Rorella, Section Rossolis.

1998; International Society of Cytology; Volume: 63; Issue: 2 Linguagem: Inglês

10.1508/cytologia.63.199

1348-7019

Yoshikazu Hoshi, Katsuhiko Kondo,

Plant Diversity and Evolution

The Drosera chromosomes studied were not localized-centromeric but diffused-centromeric. Among the Drosera taxa studied, only D. filiformis (2n=20) had 20 weak CMA-negative orDAPI-positive large bands more than 2.97 μm2 area each at the same site of 20 chromosomes. Thus, its hybrid with D. intermedia (=Drosera × hybrida, 2n=20) had ten CMA weakly-negative orDAPI-positive bands more than 3.00 μm2 each in the same site of ten chromosomes which could be of the gamete of D. filiformis. Drosera petiolaris (2n=14) displayed the meiotic chromosome configuration of six circular bivalents with four distinct chromatids held each other with end-to-end association and two univalents at metaphase I, while D. rotundifolia (2n=20) displayed ten ring-shaped bivalents, that were quite similar to the bivalents of the localized-centromeric chromosomes. These differences in CMA-positive and DAPI-negative bands, IBAS-area, and meiotic chromosome behavior might be correlated with chromosome differentiation and speciation in the species of Drosera of the Northern and the Southern Hemispheres.