The objective of this study was to physiologically characterize the reproductive compatibility of seven Japanese plum cultivars (Prunus salicina Lindl) through hybridization, fruit set and pollen tube growth (PTG) analysis. The fruit set was determined 40 days after the controlled hybridization and was carried out under field conditions. The degree of compatibility was evaluated in vivo, to determine the PTG. The cv. América had good fruit set when pollinated with cvs. Rosa Mineira (26.7%), Amarelinha (8.7%) and Reubennel (12.7%). The crosses between 'Gulf Blaze' x 'Gulf Rubi', 'Gulf Rubi x Gulf Rubi' and 'Gulf Rubi x Gulf Blaze' had fruit set of 11.36%, 3.84% and 9.94% respectively. In the laboratory tests PTG reached the egg or the ovary in all these crosses, with the exception of self-pollination of 'Gulf Rubi'. In the field, no fruit set in self-pollination of 'América' and 'Gulf Blaze' and the cross between 'América x Pluma 7' was observed. The PTG in these crosses did not reach the egg, with the exception of self-pollination of 'Gulf Blaze'. It was concluded, that only the cross between 'América' x 'Pluma 7' is incompatible, and America is a self-incompatible cultivar.
Prunus salicina; self-incompatibility; fruit set; hybridizations; in vivo pollination
