ABSTRACT The present study aimed to describe histological traits of the graft welding process and evaluate the effect of rootstocks on the physical and chemical traits and the productivity of sour passion fruit populations. The experiment was arranged in a randomized block design, in a 4x2 + 4 factorial scheme (cultivars / canopy x rootstocks), three replicates and nine plants per plot. Commercial cultivars and populations and Passiflora alata and P. nitida rootstocks, in addition to ungrafted plants were used as canopy. Cleft grafting was the grafting type adopted. Traits analyzed such as productivity and physical and chemical quality of fruits were submitted to analysis of variance and compared by the Tukey test. The canopy morphology was evaluated according to descriptors of the Ministry of Agriculture, Livestock and Supply. Grafting was carried out for each graft/rootstock combination for histological analysis. Sections were obtained by freehand cuts, stained and mounted on semi-permanent slides, examined under optical microscope and photomicrographed. Rootstocks affected the early cultivation and reduced productivity and number of fruits of passion fruit populations. Grafting did not affect the quality of fruits or the canopy morphology. Considering the complete culture cycle, P. alata species is able to be used as rootstock. The anatomical study demonstrates the occurrence of better compatibility in the connection of P. edulis tissues on P. alata, compared to grafting on P. nitida.