Subgenus Decaloba Research Articles

Pliocene seeds of Passiflora subgenus Decaloba (Gray Fossil Site, Tennessee) and the impact of the fossil record on understanding the diversification and biogeography of Passiflora.

Passiflora is a diverse genus of ~570 extant species primarily distributed in the Americas, from the eastern United States to Argentina and Chile. Nevertheless, the known fossil record of Passiflora is small. To date, only two fossil seed species have been unequivocally assigned to the genus. In this contribution, rare sulcate seeds from Gray Fossil Site are described as a third fossil seed species of Passiflora. Three partial seeds with sulcate sculpture from Gray Fossil Site, early Pliocene, Tennessee, USA, were examined, photographed, and measured. They were compared to samples of sulcate seeds from six extant Passiflora species in supersection Decaloba. A broader survey of sulcate seeds produced by modern species in the subgenera Decaloba, Deidamioides, and Tryphostemmatoides was done using published illustrations and descriptions. The Gray Fossil Site seeds are described as Passiflora sulcatasperma, sp. nov., and assigned to subgenus Decaloba, supersection Decaloba. They are characterized by their small size, elliptical shape, ridged-and-sulcate sculpture, rugulose ridges, and thin palisade seed coat. The two largest subgenera of Passiflora can be identified from Neogene fossils. Subgenus Decaloba is represented by two fossil seed species, P. bulgarica (Miocene, Bulgaria) and P. sulcatasperma (Pliocene, USA). Subgenus Passiflora is represented by fossil pollen (Miocene, Argentina and Brazil) and P. appalachiana seeds (Pliocene, USA). The distributions of fossil and modern species suggest that Passiflora may have used both North Atlantic and Antarctic routes to expand into Europe and the Asian-Oceanian Paleotropics, respectively.

Evaluation of pollen morphology of Passiflora species and hybrids (Passifloraceae)

Passiflora L. is a diverse genus of mostly New World species, many of which are still evolving to overcome the challenges of competition, predation, and habitat expansion. Pollen collected from 195 Passiflora L. taxa across six subgenera; Astrophea (DC.) Mast., Decaloba (DC.) Rchb., Deidamioides (Harms) Killip, Passiflora, Tetrapathaea (DC.) P.S. Green) and Tryphostemmatoides (Harms) Killip and 40 F1 hybrids (cultivars) were examined using Scanning Electron Microscopy (SEM) and low temperature SEM. Passiflora pollen grains are divided into two major morphological groups: species with three pairs (6 apertures) of colpi found in species in subgenera Astrophea, Deidamioides, Passiflora and Tryphostemmatoides, and those with six pairs (12 apertures) of colpi found in most species from subgenus Decaloba (Tetrapathea unknown). This study shows polymorphism and surface anomalies in the morphology of pollen grains of some species. Pollen from many Passiflora F1 hybrids were examined: many have a high percentage of sterile pollen grains, others in section Dysosmia DC. and Tacsonia Juss. in subgenus Passiflora recorded a minimal percentage of sterile grains. This may be a key evolutionary advantage as several species in these groups are now recorded as invasive weeds with worldwide distribution. The term, “sticky pollen” is revealed to be the pre-germination of pollen grains without stigmatic contact. The success of some invasive species to outcompete native flora and thrive in extreme environments is in part due to the evolution of their pollen, with the absence of pollen deformation following hybridization events promoting hybrid fitness. Pollen grain morphological evidence supports keeping three endemic Australian Passiflora species in subgenus Decaloba as a unique group.

Passiflora zapalinamensis, a new species of supersect. Bryonioides (Passifloraceae) from northeast Mexico

Passiflora zapalinamensis, a new species of the northern Mexican flora with uncinate trichomes, is herein described and illustrated. This species is endemic to the canyons and hills of the Sierra de Zapalinamé within the state of Coahuila, and the extended Sierra Madre Oriental of northeastern Mexico. It belongs to the subgenus Decaloba, supersection Bryonioides. It can be readily distinguished from its most morphologically similar species Passiflora hispidula by its subopposite to alternate glabrous nectaries, consistently rounded foliar apices, red stems and secluded distribution. Its taxonomy, ecology and conservation are discussed.

Passiflora ketura, a New Species of Passiflora Section Decaloba (Passifloraceae) from Peru

Passiflora ketura, a new species of Passiflora (Passifloraceae) endemic to the mountain forests in Amazonas Department, Northern Peru, is described and illustrated from herbarium material. It is compared to similar species and placed in subgenus Decaloba section Decaloba.

The complete chloroplast genome sequence of Passiflora xishuangbannaensis (Passifloraceae), a vine endemic to Yunnan, China

Passiflora xishuangbannaensis, Passiflora subgenus Decaloba, is a very rare endemic to the Yunnan, China. Here we report and characterize the complete chloroplast (cp) genome sequence of P. xishuangbannaensis to provide genomic resources useful for promoting its conservation and systematics. The complete genome is 135,742 bp in length and the overall GC content is 37.1%. The cp genome sequence has a typical quadripartite structure, comprising two inverted repeats (IRs: 20,604 bp) regions, which are separated by a small single-copy (SSC: 13,159 bp) region and a large single-copy (LSC: 81,375 bp) region. Moreover, a total of 122 functional genes were annotated, including 77 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogenetic analysis recovered P. xishuangbannaensis as a member of subgenus Decaloba.

Chemical Composition of the Essential Oils From Leaves and Flowers of Passiflora sexocellata and Passiflora trifasciata

The chemical composition of the essential oils of Passiflora sexocellata and Passiflora trifasciata (Passifloraceae, subgenus Decaloba) were studied for the first time. Essential oils were obtained by steam distillation of fresh leaves and flowers. The chemical composition was assessed by using GC/FID and GC/MS. For P. sexocellata leaves, the optimized analytical procedure allowed the identification of 33 compounds (75% of the total oil composition) and 29 (74% of the total oil composition) in flowers. Regarding P. trifasciata, 35 compounds (76% of the total oil composition) were detected in leaves and 32 (71% of the total oil composition) in flowers. Terpenes and mono unsaturated hydrocarbons were quantified as major constituents of the volatile fraction in flowers (17.0 to 52.6%) and (13.7 to 20.0%). Organic acids were detected in both leaves and flowers with a percentage ranging from 3.3% to 32.0%. Aldehydes were also detected in leaves (12.6 to 41.4%) and in flowers (1.4 to 5.1%). The GC/MS analyzes allowed alcohols to be detected in leaves (20.6 to 42.9%) and in flowers (8.2 to 18.1%). These compounds represent the most important feature of the large Passiflora family. Moreover, a critical role in the coevolved mechanisms of pollinators' interaction has been investigated.

Clade-Specific Plastid Inheritance Patterns Including Frequent Biparental Inheritance in Passiflora Interspecific Crosses.

Plastid inheritance in angiosperms is presumed to be largely maternal, with the potential to inherit plastids biparentally estimated for about 20% of species. In Passiflora, maternal, paternal and biparental inheritance has been reported; however, these studies were limited in the number of crosses and progeny examined. To improve the understanding of plastid transmission in Passiflora, the progeny of 45 interspecific crosses were analyzed in the three subgenera: Passiflora, Decaloba and Astrophea. Plastid types were assessed following restriction digestion of PCR amplified plastid DNA in hybrid embryos, cotyledons and leaves at different developmental stages. Clade-specific patterns of inheritance were detected such that hybrid progeny from subgenera Passiflora and Astrophea predominantly inherited paternal plastids with occasional incidences of maternal inheritance, whereas subgenus Decaloba showed predominantly maternal and biparental inheritance. Biparental plastid inheritance was also detected in some hybrids from subgenus Passiflora. Heteroplasmy due to biparental inheritance was restricted to hybrid cotyledons and first leaves with a single parental plastid type detectable in mature plants. This indicates that in Passiflora, plastid retention at later stages of plant development may not reflect the plastid inheritance patterns in embryos. Passiflora exhibits diverse patterns of plastid inheritance, providing an excellent system to investigate underlying mechanisms in angiosperms.

Karyotype and nuclear DNA content variation in Passiflora L

The Passiflora genus, which is recognized for its economic and ecological potential, has been studied in botanical, systematic and evolutionary aspects. Currently, Passiflora is represented by five subgenera subdivided into 16 supersections, 31 sections and 13 series. However, their delimitations and relationships are still conflicting. We applied classical cytogenetics to revise the chromosome number of 19 species and to define it for further nine. The classification of chromosome pairs was re-evaluated for nine species and established for further 19. For 24 species, the karyogram was assembled for the first time, and for the other four it was updated. Using flow cytometry, the nuclear DNA content was revisited for 22 species and expanded for 19. Chromosome number 2n = 12 was found for the subgenus Decaloba, as well as 2n = 18 and 2n = 20 for Passiflora, 2n = 24 for Astrophea and Deidamioides, and the unpublished 2n = 48 for P. contracta (subgenus Deidamioides). Metacentric and submetacentric chromosomes predominated in all karyotypes, except in P. lindeniana and P. arborea (subgenus Astrophea), which some acrocentric pairs occur. The nuclear 2C value ranged from 0.59 pg (P. capsularis) to 5.46 pg (P. quadrangularis), with differences exceeding 925 %. The karyotypes and nuclear genome size of the genus Passiflora supported the current subgeneric division. The evaluated characters also corroborate with the hypothesis of x = 6 as the ancestral chromosome number and the diversification by polyploidy and ascendant dysploidy. Furthermore, the cytogenetic and genome size data were complementary to systematic of the genus.

<p><strong><em>Passiflora nana</em></strong><strong>, a new species in <em>Passiflora</em> section <em>Decaloba</em> (Passifloraceae) from northern Peru</strong></p>

A new species of Passiflora L. endemic to cloud forest in northern Peru, P. nana, is described and illustrated from living and herbarium material. The new species is similar to the Colombian P. erythrophylla in flower and Ecuadorian P. hirtiflora in vestiture. The indument is pilose to hispidulous throughout with long straight white trichomes, and the plant is short, less than 2.5 m long, with a very small flower ca. 1.5 cm diam. It is placed in subgenus Decaloba supersection Decaloba section Decaloba.

Origin of the cultivated passion fruit Passiflora edulis f. flavicarpa and genomic relationships among species of the subgenera Decaloba and Passiflora.

Passiflora edulis f. flavicarpa is the most economically important species in the genus Passiflora. However, the origin of this yellow form of passion fruit remains unclear, being suggested as a hybrid (P. edulis f. edulis×P. ligularis) or wild mutant. Here, the origin and genomic relationships of P. edulis f. flavicarpa with some related species in the genus Passiflora (subgenera Decaloba and Passiflora) were investigated using genomic in situ hybridization (GISH). Genomic DNA of 18 species was used as probe, which was hybridized onto chromosomes of P. edulis f. flavicarpa. Of all genomic DNA probes tested, none allowed us to identify a specific chromosome set in P. edulis f. flavicarpa. Conversely, probes from the subgenus Passiflora, P. edulis f. edulis, P. alata, P. cincinnata, P. coccinea, P. nitida and P. vitifolia, produced intense and uniform hybridizations on all chromosomes of P. edulis f. flavicarpa. Moreover, probes from P. ligularis, P. foetida and P. sublanceolata produced more intense hybridizations in the terminal region of four chromosomes, corresponding to the DNAr 45S locus, and also dispersed, less intense, hybridization across all chromosomes. Probes from the subgenus Decaloba, P. biflora, P. capsularis, P. cervii, P. coriacea, P. micropetala, P. morifolia, P. rubra and P. suberosa, produced hybridizations restricted to the DNAr 45S sites. The hybrid origin of P. edulis f. flavicarpa could not be supported based on the GISH results, and it is suggested that this species is conspecific with P. edulis f. edulis, because the probe with DNA of this form hybridized strongly throughout the target genome. The other putative parent species, P. ligularis, showed only a distant relationship with the target genome. The results also suggest that species of the subgenus Passiflora share many repetitive sequences and that the relationship between subgenera Decaloba and Passiflora is very distant.

Palynotaxonomy of Brazilian species of Passifloraceae sensu stricto

ABSTRACT This study aims to expand knowledge of the pollen morphology of Passifloraceae and contribute to the taxonomic delimitation of the group by morphologically characterizing pollen grains of species that occur in the Brazilian state of Bahia. Thirty-six species occur in the state, one of the genus Mitostemma (M. glaziovii) and 35 of the genus Passiflora. Pollen samples were acetolysed, measured, and described using light and scanning electron microscopy. The results group the studied species into four pollen types based mainly on aperture type and number, opercular variation, and the presence/absence of ornamentation elements inside the lumina of the reticulum: Pollen type I - species belonging to the subgenera Astrophea and Deidamioides; pollen type II - subgenus Decaloba; pollen type III - subgenus Passiflora; and pollen type IV - M. glaziovii, with pollen characteristics that separate it from the other species analyzed. The results reinforce the recognition of three subgenera of Passiflora. Morphopalynologically the species have very similar pollen types except for those of the subgenus Deidamioides, which are quite diverse and thus included in another pollen type. The results reveal the importance of pollen grains for the taxonomic study of Passifloraceae.

PASSIFLORA INSOLITI

SummaryA new species of Passiflora L. in subgenus Decaloba (DC.) Rchb. from Montebello Lake, Chiapas, Mexico is described; its history, taxonomy, distribution and cultivation are discussed.

PASSIFLORA ITATIAIENSIS

SummaryA new species of Passiflora L. in subgenus Decaloba (DC.) Rchb. from Rio de Janeiro State, Brazil is described; its history, taxonomy, distribution, ecology and cultivation are discussed.

Karyotypic analyses and genomic affinity among Argentinean species of Passiflora

Abstract The genus Passiflora (Passifloraceae) has more than 500 species, nineteen are native to Argentina. By their austral distribution, these species were included in breeding programs to obtain ornamental varieties tolerant to low temperatures. The aim of this work was to know the cytogenetic characteristics of Passiflora genotypes present in a working collection, as an indispensable knowledge for the development of a breeding plan. Chromosomal preparations were performed and karyotypic characteristics, rDNA sites by FISH and affinity among subgenera by GISH were studied. Chromosome counts in fourteen Argentinean species confirmed the basic chromosome numbers previously published: x = 6 for subgenus Decaloba, x = 9 for subgenus Passiflora and x = 10 for Dysosmia. The karyotypic parameters (karyotype, haploid chromosome length and asymmetry indices) and genomic affinities among the subgenera, clarify most of the chromosomal evolution of the genus. The results obtained strongly suggest that the basic number x = 6 would be the original one and that x = 9 was originated by processes of polyploidy and descendent dysploidy. Since subgenus Passiflora possesses the largest genomes, it is postulated that evolutionary process leading to x = 9 was accompanied by unequal distribution of non-coding repetitive DNA, mainly transposable elements. These processes could explain the asymmetrical karyotypes of species of subgenus Passiflora.

Highly accelerated rates of genomic rearrangements and nucleotide substitutions in plastid genomes of Passiflora subgenus Decaloba

Plastid genomes (plastomes) of photosynthetic angiosperms are for the most part highly conserved in their organization, mode of inheritance and rates of nucleotide substitution. A small number of distantly related lineages share a syndrome of features that deviate from this general pattern, including extensive genomic rearrangements, accelerated rates of nucleotide substitution, biparental inheritance and plastome-genome incompatibility. Previous studies of plastomes in Passiflora with limited taxon sampling suggested that the genus exhibits this syndrome. To examine this phenomenon further, 15 new plastomes from Passiflora were sequenced and combined with previously published data to examine the phylogenetic relationships, genome organization and evolutionary rates across all five subgenera and the sister genus Adenia. Phylogenomic analyses using 68 protein-coding genes shared by Passiflora generated a fully resolved and strongly supported tree that is congruent with previous phylogenies based on a few plastid and nuclear loci. This phylogeny was used to examine the distribution of plastome rearrangements across Passiflora. Multiple gene and intron losses and inversions were identified in Passiflora with some occurring in parallel and others that extended across the Passifloraceae. Furthermore, extensive expansions and contractions of the inverted repeat (IR) were uncovered and in some cases this resulted in exclusion of all ribosomal RNA genes from the IR. The most highly rearranged lineage was subgenus Decaloba, which experienced extensive IR expansion that incorporated up to 25 protein-coding genes usually located in large single copy region. Nucleotide substitution rate analyses of 68 protein-coding genes across the genus showed lineage- and locus-specific acceleration. Significant increase in dS, dN and dN/dS was detected for clpP across the genus and for ycf4 in certain lineages. Significant increases in dN and dN/dS for ribosomal subunits and plastid-encoded RNA polymerase genes were detected in the branch leading to the expanded IR-clade in subgenus Decaloba. This subgenus displays the syndrome of unusual features, making it an ideal system to investigate the dynamic evolution of angiosperm plastomes.

Passiflora intricata, an apetalous new species from the Dominican Republic in Supersection Auriculatae (Passifloraceae)

A new species of Passiflora L. endemic to the Dominican Republic, P. intricata, is described and illustrated from herbarium material and living plants. The flower is unusual in Passiflora by its vestigial androgynophore and tangled thread-like corona. It is placed in subgenus Decaloba supersection Auriculatae s.str. on the basis of its plicate operculum, laminar and petiolar nectaries, grooved seeds, very reduced petals (absent in this new species) and apically attenuate coronal filaments.

A Taxonomic Revision ofPassiflorasect.Xerogona(Passifloraceae) Using Principal Component Analysis

In subgenus Decaloba (DC.) Rchb. of Passiflora L., the section Xerogona (Raf.) Killip (Passifloraceae) is a group of herbaceous vines found in subtropical and tropical regions of the Americas. Primarily distributed in Central America, with a few also found in the West Indies and South America, the species of Passiflora sect. Xerogona are recognized by their unusual dehiscent capsular fruit, the absence of bracts and laminar nectaries, and their transversely grooved seeds. Passiflora tenella Killip is the only species included in Passiflora sect. Xerogona with a fruit that does not appear to be a capsule, but the shape of the leaves and the absence of floral bracts and laminar nectaries suggest affiliation with this section. Fifteen species, including two subspecies, are recognized within Passiflora sect. Xerogona. Passiflora cobanensis Killip is distinguished as two subspecies, P. cobanensis subsp. cobanensis and P. cobanensis subsp. brevipes (Killip) T. Boza, with the latter subspecies transferred from P. brevipes Killip. From previous species circumscriptions, this section contains two problematic species complexes for P. capsularis L. and P. rubra L. The morphological variation between and within these two species complexes was examined in this study, using Principal Component Analysis and correlation matrices of morphological characters, and this variation was studied throughout their distributional ranges. Passiflora capsularis is recognized as a single variable species. Two species are recognized within the P. rubra complex, based primarily on floral characters, as P. cisnana Harms and P. rubra. Passiflora cisnana is lectotypified.

Passiflora kumandayi (Passifloraceae), a new species from the Colombian Andes in a new section within subgenus Decaloba

A new species of passion flower from the Cordillera Central of the Colombian Andes is here described; Passiflora kumandayi M.A. Buitrago A. & Coca (subgenus Decaloba, supersection Auriculata). This species, along with five other closely related Andean species, comprise a monophyletic group characterized by paired branched inflorescences and small flowers with short or absent androgynophores. A provisional key to the species in the newly described section Apodae is presented. Passiflora kumandayi is here illustrated and its affinities with related species are discussed based on morphology and phylogenetic binning analysis using molecular site weight calibration.

Morphological characterization in the genus Passiflora L.: an approach to understanding its complex variability

Morphological variation was studied in 124 accessions from 61 Passiflora L. species. Twenty-four quantitative descriptors selected for their high variation among subgenera were submitted to a principal component analysis. The first principal component (32% of total variance) was associated with flower length and secondarily with floral cup constriction, the second (27%) with flower width and bract shape, and the third (14%) with peduncle branching, stem width, and leaf length, which relates it to the differentiation of subgenera Astrophea and Deidamioides. The projection of accessions in the resulting tridimensional space consistently separates the four subgenera, as well as supersection Tacsonia of subgenus Passiflora. A neighbor joining analysis, on a selection of 32 qualitative traits and four categorized quantitative variables, clustered species according to their chromosome number and, within subgenus Passiflora, separated supersections Tacsonia (pollinated by the sword-billed hummingbird) and Distephana (pollinated by shorter-billed hummingbirds) from all other, bee-pollinated, species. Thus, the morphological study allows separating the effects of genome evolution from those of more recent and independent coevolutions concerning the pollination syndromes of supersections Tacsonia and Distephana. Within subgenus Decaloba, diverging subclusters are consistent with supersections and particular sections, with the partial exception of supersection Decaloba. Within supersection Tacsonia, subclusters correspond to one or two sections, pointing to overclassification in the current taxonomy. Among the bee-pollinated species of subgenus Passiflora, only supersection Laurifolia is clearly validated. Most of these results are consistent with molecular phylogenetic studies, except for interspecific relations among bee-pollinated species of subgenus Passiflora, which appear particularly difficult to classify.

A new species of Passiflora L. (Passifloraceae) from Guerrero and Oaxaca, México

Passiflora quadraticordata, a new species of Mexican flora with uncinate trichomes, is herein described and illustrated. This species is endemic to the southern Sierra Madre of the states of Guerrero and Oaxaca, México, and belongs to the subgenus Decaloba and the supersection Bryonioides.