Hybridization of incompatible poplars following solvent treatment of stigmas

Pretreatment of stigmas of poplar flowers with hexane or ether promoted hybridization between normally incompatible black and white poplar species. Success rates, as measured by setting of fertile hybrid seed, exceeded 95% of those resulting normally from compatible crosses. Results suggest the existence of some incompatibility factor, possibly of a lipoid nature, located on the stigmatic surfaces.