Physiological characterization of reproductive compatibility of Japanese plum

Abstract

The objective of this work was to physiologically characterize the reproductive compatibility of six Japanese plum (Prunus salicina) cultivars by evaluating fruit set and pollen tube growth (PTG). Fruit set percentage was determined after 40 days of controlled crosses made between six cultivars, in the field. The degree of compatibility was evaluated in vivo to determine PTG. Fruit set was very low for all crosses: maximum of 8.1%, with 'Reubennel' self‑pollination. At in vivo crossing, PTG showed significant variations in each female parent. The crosses between 'América' x 'Pluma 7' and 'Rosa Mineira' x 'Santa Rosa' were incompatible, while the selfing of 'América' and 'Pluma 7' showed self‑incompatibility. No fruit set was observed in the field in the cross 'Reubennel' x 'Rosa Mineira', and in the reciprocals between 'Rosa Mineira' and 'Amarelinha' x 'América' and 'Amarelinha', and 'Pluma 7' and 'Santa Rosa' x 'América'. However, with in vivo pollination, PTG reached the egg or the ovary in these crosses. Only crosses between 'América' x 'Pluma 7' and 'Rosa Mineira' x 'Santa Rosa' are incompatible, and América cultivar is self-incompatible.