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

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.

Initial growth of clonal seedlings of Passiflora mucronata genotypes in response to paclobutrazol concentrations

“…Passiflora mucronata Lam., found in the coastal restinga vegetation of the states of Espírito Santo and Rio de Janeiro (Magnago et al, 2011;Garbin et al, 2012), is a species of high agronomic interest for investigations due to its resistance to diseases such as bacterial leaf blight, fruit and branch anthracnose, and microorganisms such as Fusarium (Correia, 2019). In this context, the species becomes a viable alternative as a control method for resistance detection and studies on graft compatibility with commercial species for use as rootstocks (Alexandre et al, 2013;Oliari et al, 2016;Schmildt et al, 2018). Grafting is a form of vegetative propagation that, using resistant/tolerant rootstocks, such as P. nitida, P. gibertii, P. setacea, and P. alata, allows establishing technically superior orchards compared with those formed by seeds, with greater disease and premature plant death control, enabling the multiplication of plants with better quality fruits and increased productivity, in addition to obtaining more homogeneous orchards with increased resistance to pests and diseases (Ruggiero;Corrêa, 1980), especially considering that, in areas under crop succession and irrigation, the decrease in yield caused by Fusarium wilt has been increasing (Toledo-Souza et al, 2012).…”

Salt stress on physiology, biometry and fruit quality of grafted Passiflora edulis

“…Yellow passion fruit is traditionally grown through seeds; however, in order to minimize phytosanitary problems caused by soil pathogens, many researchers have studied the grafting of commercial species using rootstocks of wild species resistant to soil pathogens, mainly of the genus Fusarium (SANTOS et al, 2016;SCHMILDT et al, 2018), P. edulis/P. gibertii (CAVICHIOLI et al, 2011); P. edulis / P. mucronate (ALEXANDRE et al, 2013); P. edulis/P.…”