Cover Illustration: Over 50 years ago, Ownbey published the discovery of the newly formed allotetraploids of Tragopogon. Color photographs of these plants and their diploid parents and hybrids formed an historical color plate in the American Journal of Botany. Tragopogon continues to serve as a model for recent allopolyploidy, as shown on this cover and characterized by Pires et al. using molecular cytogenetics in this issue. The triangle indicates parentage and reciprocal origins of tetraploid species of Tragopogon from their diploid progenitors in North America. Arrows indicate diploid(s) contributing plastids to the tetraploids. Fluorescent in situ hybridization of centromeric (green) and subtelomeric (red) repetitive elements are shown on metaphase chromosomes of the diploid species. See Pires et al.: Molecular cytogenetic analysis of recently evolved Tragopogon (Asteraceae) allopolyploids reveal a karyotype that is additive of the diploid progenitors, pp. 1022-1035 in this issue. Cover credits: plant photographs by D. Soltis and P. Soltis, cover art composition by Enrique J. Leon.
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Copyright © 2004 by the Botanical Society of America, Inc.
