Histological aspects of mini-grafting of passiflora edulis sims. And passiflora mucronata lam.

Abstract

Abstract In Brazil, the main cultivated passion fruit species is Passiflora edulis, which is affected by Fusarium soil fungus. P. mucronata species stands out because it presents resistance to this fungus, being thus an alternative rootstock to yellow passion fruit. Therefore, the aim of this study was to evaluate the anatomy of mini-grafting by top cleft grafting and simple English type grafting, using shoot tips of adult P. edulis plants in clonal rootstocks of P. mucronata. When the rootstocks reached approximately 2.5 mm in diameter and 20 cm in height, grafting was carried out with Parafilm® tape fasteners and silicone clip. At the end of 60 days, histological analysis of the grafting region was performed to verify the formation of the scarring parenchyma tissue (callus). The filling of the mini-grafting cleft by callus was verified; however, there was no differentiation of the new vascular tissue at 60 days after grafting. During the performance of the simple English type grafting using Parafilm® tape, it was extremely difficult to encircle the tape and at the same time to join the bionts so that tissue junction is perfect. Mini-grafting by top cleft grafting using Parafilm® tape fastener is recommended.