Genetics of gynodioecy in Hawaiian Bidens (Asteraceae)

Inheritance of male sterility in all gynodioecious species of Hawaiian Bidens was investigated by experimental crosses conducted in greenhouses. Both male-sterile individuals and hermaphrodites were segregated in the progenies of openpollinated female and hermaphroditic plants growing in nature. The ratios (H:MS) of 1:0, 1:1, 3:1 were observed in the F1 generations; 3:1 and 15:1 in the F2 generations; and 1:1 and 3:1 in the backcrosses. Thirteen interspecific triple crosses and all quadruple crosses gave MS progenies, indicating a directly allelic relationship among male sterility genes in all gynodioecious species. Based on these results, A digenic-cytoplasmic model was proposed, and the evolution of gynodioecy in Hawaiian Bidens was discussed. © The Oenetical Society of Great Britain.link_to_subscribed_fulltex