Karyomorphology and GC-rich heterochromatin pattern in Passiflora (Passifloraceae) wild species from Decaloba and Passiflora subgenera

Thirteen wild species of Passiflora were analyzed using conventional and CMA/DA/DAPI staining to evaluate the karyotype diversity between and within the subgenus Decaloba and Passiflora. The karyotypic features indicate that both subgenera have a conserved chromosome number, as reported before for several species. Submetacentric (sm) chromosomes were found in species from both subgenera, suggesting that sm chromosomes are not restricted to a particular subgenus. The analysis of the karyotypic heterogeneity enabled to distribute the species in three groups, but with no support to phylogenetic and taxonomic levels. The application of fluorochromes allowed for the visualization of CMA⁺/DAPI⁻ blocks, which in our studies always correlated with the occurrence of satellites, showing that occurrence of two chromosome pairs with satellites per cell is a characteristic shared by some species from both subgenera. This feature does not always have relationship with the basic chromosome number. The data found in this study will help to understand the phylogeny, cytotaxonomy, and evolution of the genus Passiflora showing that karyotypic variation can be seen between and within the subgenus Decaloba and Passiflora.     

Passiflora tacanensis, a new species of Passiflora subgenus Decaloba supersection Cieca from Mexico

Passiflora tacanensis, a new species from southern Mexico, is described and illustrated. It was discovered during the course of a taxonomic revision ofPassiflora subgenusDecaloba supersectionCieca and is assigned to that group of apetalous passion flowers.Passiflora tacanensis is known only from one fruiting herbarium specimen that was collected in southern Mexico on Volcán Tacaná in a high mesophytic forest. It is distinguished from its closest relatives,P. coriacea, P. sexocellata, P. mcvaughiana, andP. xiikzodz, by its foliose stipules, leaves that lack laminar nectaries but possess petiolar nectaries, and wide seeds with a chalazal beak that is not well developed.     

Plant regeneration from protoplast fusion inPassiflora spp.

Summary Protoplasts were isolated from leaf explants ofPassiflora edulis var.flavicarpa (the yellow passion fruit) and from cell suspensions of fivePassiflora species. Chemical fusion was performed using polyethylene glycol and the microcolonies obtained were transferred to growth medium to produce calli. Electrophoresis of soluble proteins and analysis of isoenzymes from calli produced from the fusion experiments were performed to select somatic hybrids. Specific polypeptide bands allowed the identification of somatic hybrids betweenP. edulis var.flavicarpa (+)P. alata, P. edulis var.flavicarpa (+)P. amethystina, P. edulis var.flavicarpa (+)P. cincinnata, P. edulis var.flavicarpa (+)P. giberti andP. edulis var.flavicarpa (+)P. coccinea. An average of 3 to 5% hybrid calli were obtained. With the exception of theP. edulis var.flavicarpa (+)P. coccinea, whole plants were recovered from all hybrids. These somatic hybrids showed 4n=36 chromosomes, which represents a further evidence of their hybridity.     

Comparative cytogenetics between the species Passiflora edulis and Passiflora cacaoensis

Passiflora edulis Sims is the most economically important species of the genus Passiflora. A new species was described recently, Passiflora cacaoensis Bernacci & Souza, which displayed morphologic characteristics very similar to P. edulis. Due to the need for delimitation of the two species, karyomorphological and banding analyses were carried out. Both species have 2n = 18, with the same karyotype formula 16 m + 2sm. There was variation between the species regarding the location of satellites and the width of chromosome pairs 2, 4 and 8. C banding revealed the presence of constitutive heterochromatin in the centromeric and telomeric regions of all chromosomes in both species. However, only in P. cacaoensis did chromosomes 3 and 9 have a large quantity of heterochromatin. Fluorochrome banding revealed CMA⁺ bands only in the satellites, but no DAPI⁺ bands. Fluorescence in situ hybridisation (FISH) showed that in P. cacaoensis the rDNA 5S probe is located in a single site in the subterminal position of the long arm of chromosome 5. However, for the rDNA 45S probe, two sites were detected in terminal positions of the long arms of chromosome 7, with a bigger and stronger signal, and of chromosome 9. According to the asymmetry index and the quantity of heterochromatin, P. cacaoensis is a more basal species than P. edulis. The cytogenetic data indicate that P. cacaoensis is closely related to P. edulis, but is a different species.     

Patterns of herbivory on Passiflora leaf tissues and species by generalized and specialized feeding insects

Abstract.

• 1 The feeding patterns of specialized (Heliconius butterflies) and generalized (the grasshopper, Osmilia flavolineata) herbivores on leaf age classes and species of neotropical vines in the genus Passiflora are compared by offering them leaf discs in choice experiments.
• 2 Heliconius larvae selected young meristematic leaves over medium aged and mature leaves of Passiflora auriculata on which to feed.
• 3 Adults of O. flavolineata consumed more young leaves of P. pittieri from an array of different ages of leaf tissue, but showed no preference for young over mature leaves of P. tetrastylus or P. data.
• 4 In choice tests conducted with medium aged leaves of four species of Passiflora, O. flavolineata selected P. tetrastylus over P. pittieri and P. vitifolia, which were consumed more than P. alata.
• 5 P. alata, which was avoided by O. flavolineata in feeding trials, was the only abundant Passiflora in neotropical habitats where generalized herbivores (grasshoppers and katydids) were common.
• 6 Our results suggest that Passiflora species in forest habitats where some generalized herbivores are rare have fewer chemical defences, but retain physical defences (tough leaves and hooked trichomes) rendering them unpalatable to specialized herbivores like the larvae of Heliconius butterflies.

     

Karyology and cytotaxonomy of the genus Passiflora L. (Passifloraceae)

 The chromosomes of 31 species of Passiflora, distributed throughout the subgenera Astrophea, Calopathanthus, Distephana, Dysosmia, Passiflora, Plectostemma and Tacsonia were analysed. Three different karyotypes were observed: 2n = 12, 24, 36; 2n = 18, 72 and 2n = 20. The karyotype of these species was almost always constituted of metacentric and submetacentric chromosomes with variable karyotype symmetry. In the group with x = 6, represented by the subgenus Plectostemma, six diploid species with 2n = 12, one tetraploid with 2n = 24 (P. suberosa) and an intraspecific polyploid with 2n = 12, 36 (P. misera) were analysed. P. pentagona (subgenus Astrophea) may also be included in this karyological group since it presents 2n = 24 and may be of polyploid origin, with x = 6. The interphase nuclei in this group were areticulate, except those of P. morifolia and P. pentagona with semi-reticulate characteristics. Two small terminal heterochromatic blocks, positive for chromomycin A₃, were identified in the largest chromosome pair of P. capsularis and P. rubra, species very closely related, while P. tricuspis displayed four chromosomes with proximal blocks. In the group with x = 9, represented mainly by subgenus Passiflora, 20 species with 2n = 18 and one with 2n = 72 were studied. They presented chromosomes larger than those species with x = 6 and interphase nuclei of semi-reticulate type, except for P. mixta with areticulate nuclei. Four terminal CMA⁺ blocks were observed in P. edulis, six blocks in P. caerulea and P. racemosa, while five blocks were observed in the single P. amethystina plant analysed. P. foetida (subgenus Dysosmia), the only species with 2n = 20, exhibited six chromosomes with CMA⁺ blocks and interphase nuclei of the areticulate type. The meiotic analysis of representatives of the three groups (P. foetida, P. suberosa, P. cincinnata and P. racemosa) always presented regular pairing and regular chromosome segregation, except in P. jilekii where a tetravalent was observed. The analysis of the chromosome variation within the genus and the family suggests that the base number of Passiflora may be x₁ = 6 or x₁ = 12, whereas x₂ = 9 is only an important secondary base number. Received April 11, 2000 Accepted October 5, 2000     

ThePassiflora problem in Hawaii; prospects and problems of controlling the forest weedP. Mollissima [Passifloraceae] with heliconiine butterflies

The introduced vine,Passiflora mollissima (Bailey), poses a threat to unique natural forest areas in Hawaii. While biological control is desirable, the proximity of the crop plant,P. edulis f.flavicarpa Degener requires control agents to be highly specific.Passiflora-specialist heliconiine butterflies may exhibit this necessary specificity. We examine the potential for heliconiines as pests and control agents ofPassiflora and report preliminary laboratory and field observations on host and habitat specificity.     

The role of chromosome changes in the diversification of Passiflora L. (Passifloraceae)

Passiflora L. has more than 575 species distributed especially in the Neotropics. The chromosome number variation in the genus is highly congruent with its main subgenera, but its basic chromosome number (x) and the underlying events responsible for this variation have remained controversial. Here, we provide a robust and well-resolved time-calibrated phylogeny that includes 102 taxa, and by means of phylogenetic comparative methods (PCM) we tested the relative importance of polyploidy and dysploidy events to Passiflora karyotype evolution and diversification. Passiflora arose 42.9 Mya, with subgenus diversification at the end of the Palaeogene (Eocene-Oligocene). The basic chromosome number of the genus is proposed as x?=?6, and a strong recent diversification found in the Passiflora subgenus (Miocene) correlated to genome size increase and a chromosome change from n?=?6 to n?=?9 by ascending dysploidy. Polyploidy, conversely, appeared restricted to few lineages, such as Astrophea and Deidamioides subgenera, and did not lead to diversification increases. Our findings suggest that ascending dysploidy provided a great advantage for generating long-term persistent lineages and promoting species diversification. Thus, chromosome numbers/genome size changes may have contributed to morphological/ecological traits that explain the pattern of diversification observed in the genus Passiflora.     

Plant regeneration from protoplast cultures of Passiflora edulis var. flavicarpa Deg., P. amethystina Mikan. and P. cincinnata Mast.

Summary Protoplasts isolated from seedling cotyledons of yellow passionfruit (Passiflora edulis var. flavicarpa Deg.) and two related wild species, P. amethystina Mikan. and P. cincinnata Mast., divided in culture and produced calli. Shoot regeneration was obtained in MS medium (Murashige and Skoog 1962) containing 2.0 mg/l 6-benzylaminopurine (BAP). Regenerated plants produced roots in half-strength hormone-free MS medium and could be transferred to soil after being acclimatized.     

Tissue culture studies on species ofPassiflora

The effect of different explant sources, growth regulators and coconut water concentrations and also light radiation on tissue cultures ofPassiflora edulis var.flavicarpa was evaluated.In addition, plant regeneration was obtained from a diversity ofPassiflora germplasm. For shoot morphogenesis either cotyledonary, hypocotyledonary or leaf tissues were used to obtain cultures that formed shoots when placed on Murashige & Skoog basal medium containing 6-benzylaminopurine and coconut water. Direct organogenesis was observed.Apex cultures have been also achieved fromP. edulis var.flavicarpa, P. mollissima, P. giberti, P. maliformis andP. amethystina. Excised explants 5 mm length were placed on half-strength basal medium, free of hormones. Whole plants were recovered.Abbreviations BA 6-benzylaminopurine - CW coconut water - MS Murashige & Skoog (1962) medium - NAA 1-naphthaleneacetic acid     

1056. Passiflora bakhuisensis Vanderplank & Boender

Passiflora bakhuisensis (plate 1056) a new species of Passiflora L. in subgenus Astrophea (DC.) Mast., supersection Astrophea, section Dolichostemma Killip from Surinam is described; its taxonomy, distribution and cultivation are discussed, and a key to this and related species is provided. A new synopsis of subgenus Astrophea (DC.) Mast., supersections Astrophea and Pseudoastrophea (Harms) Feuillet & J. M. MacDougal is provided.     

A REVISION OF PASSIFLORA SECTION DYSOSMIA

Revision of Passiflora subgenus Passiflora section Dysosmia DC. (Passifloraceae). The twenty one species and 10 varieties (31 taxa) comprising subgenus Passiflora section Dysosmia DC are described and some are illustrated with photographs and line drawings. Two species, Passiflora vesicaria L. and Passiflora ciliata (Dryand) Mast., are removed from synonymy and reinstated to species rank. Passiflora baraquiniana Lemaire is removed from synonymy and given varietal status. The species Passiflora santiagana (Killip) Borhidi is reduced in rank to varietal status. Of the 38 varieties of Passiflora foetida L. described by E. P. Killip in his 1938 monograph, 28 are reduced to synonymy, four are reassigned as varieties of other species and four remain as varieties of P. foetida. A new variety, Passiflora foetida var. ellisonii Vanderplank, is described with photographs and line drawings.     

Three new species of <Emphasis Type="Italic">Passiflora</Emphasis> subgenus <Emphasis Type="Italic">Decaloba</Emphasis> (Passifloraceae) from Brazil

Three new species from Brazil are described and illustrated. Passiflora cervii, P. jiboiaensis, and P. transversalis all belong to Passiflora subg. Decaloba.     

Ethylene and polyamine production patterns during in vitro shoot organogenesis of two passion fruit species as affected by polyamines and their inhibitor

Levels of ethylene and polyamines (PAs) were measured during organogenesis of hypocotyl explants of two species of passion fruit (Passiflora cincinnata Masters and Passiflora edulis Sims f. flavicarpa Degener ‘FB-100’) to better understand the relationships of these regulators and their influence on cell differentiation and morphogenesis. Moreover, histological investigation of shoot ontogenesis was conducted to characterize the different events involved in cell redifferentiation and regulation of PA and ethylene levels. A delay was observed in morphogenic responses of P. edulis f. flavicarpa as compared to P. cincinnata, and these changes coincided with production of elevated levels of polyamine and ethylene levels. During differentiation, cells showed high rates of expansion and elongation, and high ethylene levels were associated with high PA levels, suggesting that the two biosynthesis pathways were highly regulated. Moreover, their interaction might be an important factor for determining cell differentiation. The addition of PAs to the culture medium did not promote organogenesis; however, the incorporation of the PA inhibitor methylglyoxal bisguanylhydrazone in the culture medium reduced shoot bud differentiation, suggesting the need to maintaining a minimum level of PAs for morphogenic events to take place.     

In vitro culture of adult and juvenile bud explants of Passiflora species

Cultivar E23, an F1 hybrid of P. edulis and P. edulis f. flavicarpa is usually propagated by shoot-tip grafting. Various media were tested to evaluate the potential of E23 for in vitro propagation. Adult tissue was difficult to culture and did not respond to media containing low (<10 µM) concentrations of growth regulators. Growth of adult buds on intact stem sections was promoted by 1 week of dark incubation on MS basal medium plus 150 µM 2iP, 200 µM adenine sulphate and 17.1 µM IAA (3 mg l^–1), and further developed into shoots on MS medium plus 4.9 µM 2iP (1 mg l^–1) and 5.7 µM IAA (1 mg l^–1). By contrast, juvenile shoots of E23, and Passiflora species: edulis f. flavicarpa, edulis, alata, caerulea, mollissima, coccinea, herbertiana and suberosa grew rapidly on MS medium plus 10 µM kinetin and 5 µM IAA. Rapid multiplication was achieved on MS plus 20 µM BA, 10 µM kinetin, 5 µM IAA, and roots initiated on MS plus 5 µM IAA.Abbreviations IAA indole-3-acetic acid - 2iP N6-iso pentenyl adenine - BA N6-benzyl adenine     

A new species of Passiflora (Passifloraceae) from Amazonian Brazil

Passiflora cordistipula, a new species of subg.Passiflora, ser.Lobatae, from the state of Amazonas, Brazil, is described and illustrated.     

Phylogenetic relationships among Passiflora species based on the glutamine synthetase nuclear gene expressed in chloroplast (ncpGS)

This paper presents the first molecular phylogeny of the genus Passiflora encompassing almost all sections of this large genus. The nuclear-encoded chloroplast-expressed glutamine synthetase gene (ncpGS) was used to examine the relationships among Passiflora species (passionflowers), which was then compared with the new classification proposed by Feuillet and MacDougal. The resulting Bayesian, likelihood, and parsimony trees are congruent and well supported. The 90 Passiflora species examined apparently split into eight main subgenera: Plectostemma, Granadilla, Astrophea, Deidamioides, Polyanthea, Dysosmia, Tetrapathea, and Tryphostemmatoides. These results are in overall agreement with the Feuillet and MacDougal's classification but here we propose that three additional subgenera, Polyanthea, Dysosmia, and Tetrapathea, should be maintained. We observe a striking overall correlation between the phylogenetic position of the different species and their chromosome number. The first clade contains the arborescent species of the subgenus Astrophea, with n=12. The second clade, subgenus Plectostemma, includes species from four subgenera of Killip's classification with n=6 chromosomes. The last clade, subgenus Granadilla, includes species of seven old subgenera with n=9. Subgenus Dysosmia, with a variable chromosome number of n=9-11, is considered here as a separate subgenus closely related to the subgenus Granadilla.