Margarete Magalhães Souza

Diversidade genética entre genótipos comerciais de maracujazeiro-amarelo (Passiflora edulis f. flavicarpa) e entre espécies de passifloras nativas determinada por marcadores rapd

The genetic variability among yellow passion fruit genotypes was evaluated using RAPD as genetic markers of DNA. For that, genetic materials were collected in commercial populations from traditional production fields of the North Fluminense (Itaperuna, Sao Francisco do Itabapoana, Campos of Goytacazes, RJ-Brazil). The diversity among the cultivated species Passiflora edulis f. flavicarpa Deg. and species related P. alata, P. giberti, P. cincinnata, P. foetida, P. edulis. P. maliformis, P. mucronata, P. suberosa, P. malacophylla, was also estimated. For the study on yellow passion fruit, expressive genetic diversity was not verified; the populations were distributed according to its origin, and the individuals collected in Sao Francisco do Itabapoana presented major consistency in its grouping, once the formation of the groups a larger number of those individuals were allocated among the same group. For the interspecific study, it was verified that P. maliformis was in a different, but close group to P. mucronata. P. alata was allocated in an isolated group as well as P. giberti. For P. cincinnata and P. edulis (purple passion fruit), both were allocated in the same group, evidencing proximity between the same ones while P. foetida and P. suberosa formed a single group.

Passion flower hybrids and their use in the ornamental plant market: perspectives for sustainable development with emphasis on Brazil

The Passiflora L. (Passifloraceae) genus consists of about 500 species widely distributed throughout tropical and subtropical regions, commonly known as the passion flower. The passion flowers are considered ornamental plants because of the exotic beauty of their flowers and variant foliage. Since their introduction to the Old World, around 1625, seventeenth century, they have been used to decorate European glasshouses and gardens. Interspecific hybridization is used to produce single ornamental plants. However in some countries, such as Brazil, being centre of origin of many species, the potential value of these species has hardly been exploited. The beauty of these wild species and their hybrids is little known in Brazil. Therefore it is here intended to highlight the productive and commercial potential of the passion flowers for the purpose to generate an income in family agriculture, while maintaining the ecological balance and optimizing the use of natural resources.

Cytogenetic studies in some species of Passiflora L. (Passifloraceae): a review emphasizing Brazilian species

The Passifloraceae is represented by species of tro pical and subtropical origin. The Passiflora is the richest genus with approximately 450 species, 200 of them being n ative to Brazil. Recent karyological studies have r eported the basic chromosome number for the Passiflora genus as x = 6, whereas x = 9, x = 10 and x = 12 were established as secondary basic numbers. High rates of fertility oc cur in most Passiflora species, since both meiotic index and pollen viability are above 90%. Unusual meiotic beh avior has been described in some taxa. Unviable pol len were observed in some diploids species. The genome size varies from 1.83 to 5.36 pg, and significant inters pecific variance has been observed. Studies using the FISH methodology have shown that there are two to three rDNA 45S sites and one 5S site in the species analyzed. In treview, information about the above-mentioned sis presented and discussed in detail.

Meiotic irregularities and pollen viability in Passiflora edmundoi Sacco (Passifloraceae)

Abstract Meiotic and pollen viability studies were conducted in Passiflora edmundoi Sacco (n = x = 9). For meiotic studies anthers were squashed in a drop of 1% acetic carmine. For analysis of pollen viability, pollen grains of flowers at anthesis were stained with two stains, lugol and Alexander stain. At diakinesis frequency of bivalents was high (86% of pollen mother cell observed) and it was observed other pairing patterns (7 II + 1 IV; 5 II + 2 IV; and 18 I). The average number of chiasmata per cell was 9.3, in concordance with high frequency of bivalents. Meiotic phases showed the presence of spindle irregularities, asynchrony, and other abnormalities as laggard chromosomes and anaphase bridges. Different post‐meiotic products were observed and the frequency of triads was higher than monads, dyads, and polyads; however the meiotic index was 97.2% and the pollen viability was 97.9% suggesting meiotic stability. Sterile pollen was sorted in two categories: empty (60.3%) and shrunken (contracted cytoplasm) grains. The high meiotic index, pollen viability, frequency of chiasmata and bivalent pairing indicate that the species is meiotic stable and can be used in selection programs and intra and inter‐specific crosses beyond the meiotic irregularities observed.

Structural, hystochemical and cytochemical characteristics of the stigma and style in Passiflora edulis f. flavicarpa (Passifloraceae)

Studies were carried out on anatomic aspects of the stigma and style of yellow passionfruit. The stigmatic style consisted of papillae, many layers of sub-epidermal cells and a central transmitting tissue. The stigma was of dry, unbranched, multicellular multiseriate papillate type and the cells were highly vacuolated with walls that were relatively thin consisting of compactly arranged fibrils. The style was solid with a central core of transmitting tissue that had intercellular spaces containing a matrix that included polysaccharidic and lipidic substances. During development, cells of the transmitting tissue were arranged compactly while the mature pistil showed cells with a little more loosely arranged intercellular spaces. Both the mature stigma and style contained a peripheral cytoplasmic layer showing a cytoplasmic profile with a prominent nucleus containing a nucleolus, evenly distributed mitochondria, extensive RER, ribosomes and amylochloroplasts.

Hybridization among wild passionflower species

(Hybridization among wild passionflower species). Passion fruits are appreciated for their ornamental value, since their flowers are showy and display a wide variety of colors. In addition, many hybrids have been produced and used in other countries. The genotypes used in selection of plants with ornamental characteristics are hybrid progenies which are used in various crossing strategies. Thus, the aim of this work was to obtain interspecific hybrids, perform backcrossing and obtain progenies from crossings between hybrids, and to determine the reproductive compatibility between the progenitors involved. The percentage of fertilized flowers, germination, and the number of fruits, seeds and plants obtained through crossing were recorded. A series of 374 crossings involved seven species and two hybrids. Crossings such as Passiflora gibertii N. E. Brown vs. P. kermesina Link & Otto and P. gibertii vs. P. alata Curtis did not produce seeds. The largest percentage of fertilized flowers (86%) was recorded for the crossing P. gardneri Mast.vs. P. cincinnata Mast.; yet, the seeds produced did not show endosperm. Interspecific hybrids were obtained from the crossings P. gardneri vs. P. alata, P. watsoniana Mast.vs. P. alata, P. watsoniana vs. P. gardneri and P. gardneri vs. P. gibertii. Seeds generated from backcrossings involving the hybrids P. sublanceolata (sin. P. palmeri var. sublanceolata (Killip) J. M. MacDougal) vs. P. foetida var. foetida L. (HD13-133 and HD13-141) and F2 reached high germination percentages.

Germinação in vitro de grãos de pólen em Passiflora suberosa L. para sua utilização em hibridação interespecífica

In order to evaluate the pollen performance of Passiflora suberosa, in vitro germination of pollen in plants grown on greenhouse at Ilheus, South of Bahia, was studied. Statistical analysis was performed considering a randomized experimental design, with six treatments that consisted of collection times, from 7:00 to 5:00. The germination element was the same used for yellow passion fruit, and the slides were incubated at 28°C (+ 1°C). There was a significant difference (P<0.01) among the six collect times tested, and among plants at 7:00 and 8:00, showing heterogeneity among the genotypes. The average percentage of pollen germination was negatively influenced by the later testing times. The greatest germination index was at 7:00 and 9:00.

A putative mutant of a self-compatible yellow passion fruit with the corona color as a phenotypic marker

Yellow passion fruit (Passiflora edulis f. flavicarpa) is a self-incompatible crop with purple corona flowers (PCF). Plants exhibiting white corona flowers (WCF) were observed in an experimental field located in Campos dos Goytacazes - RJ, Brazil. This study was performed in order to test the fertility of these genotypes through studies of in vivo pollination, meiotic behavior and pollen viability. Using in vivo pollination, the mean fruit set percentage, obtained from self-pollinations at the moment that flowers open, was 70.83% in WCF and 0% in PCF. In terms of cytological analysis, for both kinds of plants, WCF and PCF, the meiotic behavior was considered regular, considering the high meiotic index estimated for both of them, 96.3% and 97.7%, and pollen viability, 98% and 99.5%, respectively. Such results suggest that the genotype WCF is self-compatible and interesting for use in genetic improvement of yellow passion fruit.

Reproductive studies in ipecac (Psychotria ipecacuanha (Brot.) stockes; Rubiaceae): pollen development and morphology

The aim of this work was to carry out the reproductive studies on Brazilian accessions of ipecac, Psychotria ipecacuanha. It presented heterostyly, with brevistylous and longistylous flowers. The pollen development was observed from the sections of the anthers embedded in resin. Anther development was normal as usually observed in dicotyledones, displaying four layers: outer epidermis, endothecium, middle layer and inner tapetum. The pollen was bicellular and filled with starch at the microspore stage. Pollen morphology was studied using SEM, which showed pollen polymorphism within and between the two floral morphs. Five types of pollen with reticulate or perforate exine were identified. The characteristics showed that the sexual process was as important as the vegetative propagation for the reproduction of this species.

Passiflora cacao (Passifloraceae), a New Species from Southern Bahia, Brazil

Abstract.  Passiflora cacao Bernacci & M. M. Souza is described. The Passifloraceae has a limited known distribution area in southern Bahia, Brazil. This new species is not very abundant and occurs in a mountainous area associated with dense ombrophilous forest noteworthy for its great biodiversity, including many species of hummingbirds. Passiflora cacao is similar to P. edulis Sims, but it can easily be recognized by the cylindrical hypanthium and winged seeds. In addition, the flowers are usually smaller, with inner corona and outer corona series greater in number.