Genetic differentiation during speciation in the Helianthus debilis complex [Sunflowers]

• Published in: Evolution 1983-11, Vol.37 (6), p.1119-1127
• Main Author: Wain, R.P
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Alleles; Biological and medical sciences; Biological evolution; Biological taxonomies; Breeding; Evolutionary genetics; Fundamental and applied biological sciences. Psychology; Generalities; Generalities. Genetics. Plant material; Genetic distance; Genetic loci; Genetic variation; Genetics and breeding of economic plants; Genetics of eukaryotes. Biological and molecular evolution; Helianthus debilis; Keys; Plant material; Population genetics; Taxa
• ISSN: 0014-3820; 1558-5646
• DOI: 10.1111/j.1558-5646.1983.tb00226.x

Techniques of horizontal starch gel electrophoresis were employed to estimate levels of genetic differentiation at various levels of evolutionary divergence in the Helianthus debilis complex of sunflowers. Local populations of the same taxon are genetically very similar (D = .010 ± .003). Subspecies of the 'debilis' breeding assemblage (D = .080 ± .033) are eight times more differentiated than local populations. The semispecies 'debilis' and 'praecox' exhibit approximately the same degree of genetic differentiation as subspecies (D = .063 ± .015). The average genetic distance among the closely related species H. debilis and H. petiolaris increases to .142 ± .011, with the 'praecox' (D = .121 ± .000) and 'debilis' (D = .151 ± .012) breeding assemblages being approximately equally differentiated from H petiolaris. Finally, H. debilis and the distantly related species H radula are genetically quite distinct (D = .491 ± .032).