Reproductive relationships between annual species ofCalendula (Compositae)

  title={Reproductive relationships between annual species ofCalendula (Compositae)},
  author={Chaia C. Heyn and A. Joel},
  journal={Plant Systematics and Evolution},
Breeding experiments were carried out inCalendula species. In the annuals, which are selfers, rarely some outcrossing was observed only in the most peripheral flowers. In experimental crosses fruit was produced in all combinations. Fertile F1 and F2 hybrids could be grown from crosses between parents with similar chromosome numbers:C. palaestina ×C. pachysperma and crosses of different morphological forms ofC. arvensis. In crosses of species with different chromosome numbers at least partly… CONTINUE READING