ABSTRACT Passiflora cincinnata Mast. is a wild passion fruit species widely distributed in Brazil, with diverse economic potential and source of resistance to biotic and abiotic stress factors. Despite this, molecular genetic studies on this species are incipient, which limits the definition of priority regions for conservation and identification of accessions to be prospected for germplasm banks and inserted in genetic improvement programs. Thus, this study aimed to characterize the structure and genetic diversity of P. cincinnata accessions using inter simple sequence repeat (ISSR) markers. The study was carried out using leaf samples from 213 accessions of P. cincinnata, with 158 accessions from six natural populations (collectively considered in this study as a hypothetical metapopulation) in the state of Bahia, Brazil, and the other 55 accessions from two collections of Embrapa Cerrados and Embrapa Cassava & Fruits active germplasm banks (AGBs). Genetic estimates were based on an analysis of the amplification profile of 12 ISSR primers. Descriptive statistics analysis and the polymorphic information content (PIC) and expected heterozygosity (He) estimates were carried out using the GENES software. Approaches based on the Bayesian model, principal coordinate analysis (PCoA), and analysis of molecular variance (AMOVA) were used to assess the genetic structure. Passiflora cincinnata populations/collections showed high polymorphism rates. The metapopulation showed 25.3% of private markers/alleles. The metapopulation is structured in at least three genetic groups, while AGBs in two genetic groups. AMOVA indicated higher diversity within populations, with low differentiation between them.

Passion fruit woodiness disease, caused by the Cowpea aphid-borne mosaic virus (CABMV), is one of the leading phytosanitary challenges of passion fruit production. Passiflora cincinnata has been recognized for its potential in genetic improvement due to its highest resistance to CABMV and other phytopathogens. Metabolomic and histological alterations of P. cincinnata infected with CABMV were evaluated and searched for differential responses during the asymptomatic or symptomatic infection phases to correlate them with the mechanisms of metabolic defense. The metabolites of infected plants were analyzed by liquid chromatography-mass spectrometry. Based on the metabolomic profile, the times of infection were grouped into early or late infection phases. The metabolites related to CABMV infection were classified as alkaloids, saponins, phospholipids and acids. This study can assist agricultural institutions or farms in the early diagnosis and correct management of CABMV infection and contribute to the genetic improvement of the Passiflora genus against this disease.

Abstract Sweet passion fruit (Passiflora alata Curtis) is a species native to Brazil that is economically important for fruit consumption and can also be used as an ornamental plant. The objective of this work was to evaluate different forms of storing Passiflora alata seeds for the purpose of preserving accessions in germplasm banks. Three experiments were performed. In the first, the seeds without aril were stored for two periods (one and three years) in plastic bags and in in vitro culture medium at two temperatures. In the second, the seeds with and without aril were stored for one year in plastic boxes and in vitro culture medium at two temperatures. In the third, the seeds were kept for two years in different in vitro culture media. The seeds quickly lost viability when stored for one year conventionally in a cold chamber with 25% emergence, but remained viable when were stored in vitro with 90% emergence. Therefore, the use of in vitro culture medium is an innovative way to preserve sweet passion fruit seeds at 25 oC. The seeds of the Passiflora alata evaluated should be considered recalcitrant.

Abstract The influence of the grafting height (5, 10, 20 and 30 cm above the root collar) of P. edulis on P. gibertii was evaluated on the incidence of Fusarium wilt and horticultural performance. Plants of P. gibertii grafted on P. edulis and non-grafted plants of both species were also studied. In addition, histopathological studies were also performed on the roots of non-grafted P. edulis collected at three severity stages of Fusarium wilt. In greenhouse, the graft take was inversely related to the grafting height in general. In the field conditions, the plant growth of P. gibertii grafted on P. edulis was superior to its reciprocal grafting, even though the former combination was susceptible to Fop. Plants of P. edulis grafted on P. gibertii at all grafting heights did not present symptoms of Fop, and the number of fruit yield and quality were equivalent, but plant growth was decreased in relation to the non-grafted plants. Starch depletion in the root system of P. edulis was directly related to the severity of the Fusarium wilt. P. gibertii was confirmed as a Fusarium wilt resistant rootstock of P. edulis, with minimal influence of the grafting height for the control of the disease.

ABSTRACT The genus Passiflora is the most diversified of the Passifloraceae, and its palynology presents wide morphological variability. The objective of the study was to evaluate the pollen morphology of 18 Passiflora species in order to identify informative pollinic characteristics to contribute to the taxonomic classification of the genus. The morphology of the pollen grains and the exine structure were investigated using light microscopy and scanning electron microscopy. Differences in the pollen morphology were found in the studied species, mainly in terms of shape, pollen aperture and ornamentation pattern of the exine. Most of the species belonging to the subgenus Passiflora presented ornamented 6-syncolpate pollen grains with an oblate-spheroidal shape and an exine with large lumens. In the subgenus Decaloba the pollen grains were 6-colporate, 12-colpate and 12-colporate, with subprolate to prolate-spheroidal shape, as well as an exine with smaller lumen size and few ornamented. The pollen morphology of the species of the subgenera Passiflora and Decaloba has shown palynological characteristics that have specific diagnostic value, thus allowing a better understanding of the taxonomy of the genus Passiflora.