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1.
J Chem Ecol ; 42(4): 300-4, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27074793

RESUMO

Inflorescences of Araceae pollinated by cyclocephaline scarab beetles are visited frequently by a wide array of other arthropods that exploit floral resources without taking part in pollination, including earwigs, flies, and true bugs. To date, nothing is known about the cues these insect visitors use to locate the inflorescences and whether or to what extent floral scents play a role. An aroid visited by large numbers of plant bugs (Miridae) in addition to cyclocephaline scarab beetle pollinators is the Neotropical species Dieffenbachia aurantiaca. We identified the plant bug species and investigated their behavior and arrival time on the inflorescences. To test the importance of olfactory cues in locating their host we conducted experiments with open and gauze-bagged inflorescences as well as natural scent samples of D. aurantiaca. Inflorescence scents were analyzed by gas chromatography linked to mass spectrometry (GC/MS), and the attractive potential of the main scent compound was determined by behavioral assays. Three species of Neella, the most common one being N. floridula, visited the inflorescences at nightfall, shortly after the beginning of scent emission, and showed feeding and copulation activity. Bagged inflorescences as well as natural scent samples attracted similar numbers of plant bugs as the non-bagged inflorescences, showing that olfactory cues are sufficient for them to locate their host. Cis-jasmone was the major component within the inflorescence scent bouquet. In two-choice field bioassays, this compound proved to be highly attractive to Neella, and thus obviously plays a key role in finding host plants.


Assuntos
Araceae/química , Ciclopentanos/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Heterópteros/fisiologia , Inflorescência/química , Oxilipinas/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos , Animais , Inflorescência/fisiologia , Odorantes/análise , Polinização , Fatores de Tempo
2.
Ann Bot ; 112(8): 1577-95, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23884395

RESUMO

BACKGROUND AND AIMS: In the Lamiales, indeterminate thyrses (made up of axillary cymes) represent a significant inflorescence type. However, it has been largely overlooked that there occur two types of cymes: (1) ordinary cymes, and (2) 'pair-flowered cymes' (PFCs), with a flower pair (terminal and front flower) topping each cyme unit. PFCs are unique to the Lamiales and their distribution, origin and phylogeny are not well understood. METHODS: The Lamiales are screened as to the occurrence of PFCs, ordinary cymes and single flowers (constituting racemic inflorescences). KEY RESULTS: PFCs are shown to exhibit a considerable morphological and developmental diversity and are documented to occur in four neighbouring taxa of Lamiales: Calceolariaceae, Sanango, Gesneriaceae and Plantaginaceae. They are omnipresent in the Calceolariaceae and almost so in the Gesneriaceae. In the Plantaginaceae, PFCs are restricted to the small sister tribes Russelieae and Cheloneae (while the large remainder has single flowers in the leaf/bract axils; ordinary cymes do not occur). Regarding the origin of PFCs, the inflorescences of the genus Peltanthera (unplaced as to family; sister to Calceolariaceae, Sanango and Gesneriaceae in most molecular phylogenies) support the idea that PFCs have originated from paniculate systems, with the front-flowers representing remnant flowers. CONCLUSIONS: From the exclusive occurrence of PFCs in the Lamiales and the proximity of the respective taxa in molecular phylogenies it may be expected that PFCs have originated once, representing a synapomorphy for this group of taxa and fading out within the Plantaginaceae. However, molecular evidence is ambiguous. Depending on the position of Peltanthera (depending in turn on the kind and number of genes and taxa analysed) a single, a double (the most probable scenario) or a triple origin appears conceivable.


Assuntos
Flores/anatomia & histologia , Lamiaceae/anatomia & histologia , Filogenia , Biodiversidade , Flores/crescimento & desenvolvimento , Inflorescência , Lamiaceae/crescimento & desenvolvimento
3.
Am J Bot ; 99(10): 1666-79, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22965851

RESUMO

PREMISE OF THE STUDY: Floral traps are among the most sophisticated devices that have evolved in angiosperms in the context of pollination, but the evolution of trap pollination has not yet been studied in a phylogenetic context. We aim to determine the evolutionary history of morphological traits that facilitate trap pollination and to elucidate the impact of pollinators on the evolution of inflorescence traps in the family Araceae. • METHODS: Inflorescence morphology was investigated to determine the presence of trapping devices and to classify functional types of traps. We inferred phylogenetic relationships in the family using maximum likelihood and Bayesian methods. Character evolution of trapping devices, trap types, and pollinator types was then assessed with maximum parsimony and Bayesian methods. We also tested for an association of trap pollination with specific pollinator types. • KEY RESULTS: Inflorescence traps have evolved independently at least 10 times within the Araceae. Trapping devices were found in 27 genera. On the basis of different combinations of trapping devices, six functional types of traps were identified. Trap pollination in Araceae is correlated with pollination by flies. • CONCLUSIONS: Trap pollination in the Araceae is more common than was previously thought. Preadaptations such as papillate cells or elongated sterile flowers facilitated the evolution of inflorescence traps. In some clades, imperfect traps served as a precursor for the evolution of more elaborate traps. Traps that evolved in association with fly pollination were most probably derived from mutualistic ancestors, offering a brood-site to their pollinators.


Assuntos
Araceae/anatomia & histologia , Araceae/fisiologia , Evolução Biológica , Inflorescência/anatomia & histologia , Inflorescência/fisiologia , Insetos/fisiologia , Animais , Filogenia , Epiderme Vegetal/citologia , Polinização/fisiologia
4.
Angew Chem Int Ed Engl ; 38(9): 1279-1281, 1999 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29711724

RESUMO

Bent bonds in the strained fullerene system, restricted to the [5,6] bonds, were detected by high-resolution X-ray structure analysis of the 1,2-dihydro[60]fullerene derivative 1. In addition the maxima of electron densities are higher in the [6,6] bonds than in the [5,6] bonds-an important finding with respect to the question of the extent of electron delocalization in fullerenes.

5.
Bot J Linn Soc ; 172(3): 385-397, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25821243

RESUMO

Pollinators have long been known to select for floral traits, but the nature of this relationship has been little investigated in trap pollination systems. We investigated the trapping devices of 15 Arum spp. and compared them with the types of insects trapped. Most species shared a similar general design of trap chamber walls covered in downward-pointing papillate cells, lacunose cells in the chamber wall and elongated sterile flowers partially blocking the exit of the trap. However, there was significant variation in all these morphological features between species. Furthermore, these differences related to the type of pollinator trapped. Most strikingly, species pollinated by midges had a slippery epidermal surface consisting of smaller papillae than in species pollinated by other insects. Midge-pollinated species also had more elongated sterile flowers and tended to have a larger lacunose area. We conclude that pollination traps evolve in response to the type of insect trapped and that changes to the slippery surfaces of the chamber wall are an important and previously little recognized variable in the design of pollination traps.

6.
Eur J Cardiothorac Surg ; 44(5): 821-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23644700

RESUMO

OBJECTIVES: The arterial switch operation (ASO) is the method of choice for the Taussig-Bing heart. The aim of the study was to analyse the long-term outcome of correction of the Taussig-Bing heart. METHODS: Between 1986 and 2011, 44 infants, including 18 newborns, underwent an ASO. The staged and the primary approach were used in 9 and 35 patients, respectively. Aortic arch (AA) obstruction (n = 26) and right ventricle outflow tract obstruction (n = 34) were common. The mean age at corrective surgery was 112.9 days; the mean weight was 4.17 kg. RESULTS: There were 1 early and 4 late deaths. Overall survival was 88% at 15 years, with a mean follow-up of 9.2 years. Freedom from reoperation was 67% at 15 years of follow-up. Eight and 6 patients required right and left ventricular outflow tract surgery, respectively, including resection of the right ventricular outflow tract obstruction (n = 8), a transanular patch (n = 6), aortic valve reconstruction (n = 3), aortic valve replacement (n = 2) and AA reoperation (n = 4). Freedom from aortic regurgitation >mild or aortic valve replacement/reconstruction was 76% at 15 years of follow-up. Freedom from any event was 56% at 15 years of follow-up. All patients are in sinus rhythm, and biventricular function is well-preserved in 95% of patients. All patients are doing well; 86% of them are without medication. CONCLUSIONS: Corrective surgery offers excellent survival benefits and encouraging long-term functional outcomes, regardless of the coronary anatomy and associated lesions. Normal biventricular function is preserved in the vast majority of patients, and >3/4 of patients are without cardiac medication. Nevertheless, TBH associated with a complex anatomy continues to be a risk factor for long-term morbidity, and redos and reinterventions are equally common on both outflow tracts. Progressive neoaortic regurgitation and neoaortic root dilatation might be a problem in the future; therefore, close lifelong surveillance of patients is necessary.


Assuntos
Procedimentos Cirúrgicos Cardiovasculares/efeitos adversos , Procedimentos Cirúrgicos Cardiovasculares/métodos , Dupla Via de Saída do Ventrículo Direito/cirurgia , Insuficiência da Valva Aórtica/etiologia , Arritmias Cardíacas/etiologia , Feminino , Humanos , Lactente , Estimativa de Kaplan-Meier , Masculino , Estudos Retrospectivos , Resultado do Tratamento , Obstrução do Fluxo Ventricular Externo/etiologia
7.
Am J Bot ; 96(6): 1055-67, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21628256

RESUMO

Extreme modification and reduction in floral morphology presents an obstacle to determining the evolutionary relationships and homologies of the holoparasites in Balanophoraceae. Developing flowers and inflorescences of two dioecious species, Balanophora papuana and B. elongata, were compared to each other and to the monoecious B. fungosa. Intermingled with flowers in the male inflorescences are bracts (B. elongata) or bract parts (B. papuana). In the latter, early cessation of bract tip growth results in two half-bracts, which become displaced during inflorescence elongation, thus disproving the view that these bract-like structures are axial in nature. Male flower primordia emerge in positions axillary to the dividing bracts, and both arise in a spiral sequence. This pattern is modified in B. papuana by the formation of pseudowhorls of four. In both species, the staminate flowers consist of a generally four-merous perianth and a synandrium of congenitally fused stamens. Male flower and bract ontogeny (but not pollen sacs) conform to patterns seen in other angiosperms. More problematic are the carpellate flowers whose primordia arise in irregular order between club-shaped, radially symmetrical organs called claviform bodies. The interpretation that these bodies are homologous to the peltate bracts of Helosideae appears plausible, but cannot explain their nonspiral initiation and radial symmetry.

8.
Am J Bot ; 96(5): 989-1010, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-21628251

RESUMO

The 'didymocarpoid Gesneriaceae' (traditional subfam. Cyrtandroideae excluding Epithemateae) are the largest group of Old World Gesneriaceae, comprising 85 genera and 1800 species. We attempt to resolve their hitherto poorly understood generic relationships using three molecular markers on 145 species, of which 128 belong to didymocarpoid Gesneriaceae. Our analyses demonstrate that consistent topological relationships can be retrieved from data sets with missing data using subsamples and different combinations of gene sequences. We show that all available classifications in Old World Gesneriaceae are artificial and do not reflect natural relationships. At the base of the didymocarpoids are grades of clades comprising isolated genera and small groups from Asia and Europe. These are followed by a clade comprising the African and Madagascan genera. The remaining clades represent the advanced Asiatic and Malesian genera. They include a major group with mostly twisted capsules. The much larger group of remaining genera comprises exclusively genera with straight capsules and the huge genus Cyrtandra with indehiscent fruits. Several genera such as Briggsia, Henckelia, and Chirita are not monophyletic; Chirita is even distributed throughout five clades. This degree of incongruence between molecular phylogenies, traditional classifications, and generic delimitations indicates the problems with classifications based on, sometimes a single, morphological characters.

9.
Am J Bot ; 93(3): 327-43, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21646194

RESUMO

The recent establishment of the new family Calceolariaceae, separated from Scrophulariaceae on the basis of molecular evidence, is complemented here by a scanning electron microscopy study of floral morphology and development of 12 species encompassing all genera (Calceolaria, Jovellana, and Stemotria [= Porodittia]). All species showed a similar pattern of organ initiation. The slightly zygomorphic, four-merous calyx is the first floral organ series initiated, with the primordia emerging consecutively in a unidirectional (dorso-ventral) succession. The two entire corolla lips in Calceolaria and Jovellana arise as uniform meristematic ridges (sometimes with a central emargination, especially in Jovellana), kept apart by two lateral stamen primordia. Later the margins of the lips fuse across the backs of the young stamens, giving rise to the short corolla tube (late sympetaly). Stemotria stands out by having three stamens instead of two and a bilobed lower lip, resulting in a trimerous corolla. Similar architecture was found in teratological flowers of Calceolaria. The perianth of Calceolariaceae is shown to be derived from a tetramerous condition, not from pentamery as traditionally believed. This is in agreement with the separation of Calceolariaceae from Scrophulariaceae and with their placement in succession of Oleaceae and Tetrachondraceae in the basal Lamiales. The hitherto puzzling molecular evidence is thus supported by morphological-developmental features of the flower.

10.
Am J Bot ; 90(2): 321-9, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21659123

RESUMO

The systematic position and generic differentiation of the morphologically and geographically outstanding tribe Epithemateae (Gesneriaceae) was analyzed using the rbcL/atpB-spacer and trnL-F intron-spacer regions of chloroplast DNA. In our analysis Epithemateae forms a strongly supported monophyletic clade (bootstrap [BS] = 100%; jackknife [JK] = 100%; decay index [DI] = 12) and appears as sister to the rest of the paleotropical Gesneriaceae (= subfamily Cyrtandroideae). The paleotropical Gesneriaceae form a monophyletic group (BS = 88%; JK = 85%; DI = 3) that is sister to the neotropical Gesneriaceae (subfamily Gesnerioideae) plus Austral Gesneriaceae (subfamily Coronantheroideae) (BS = 99%; JK = 98%; DI = 10). Within Epithemateae Rhynchoglossum is sister to the remaining Epithemateae (BS = 97%; JK = 96%; DI = 12), in which Epithema is sister to a clade of two genera: Loxonia/Stauranthera (BS = 68%; JK = 64%; DI = 1), which form, together with Epithema, a sister clade (BS = 85%; JK = 83%; DI = 2) to Whytockia and Monophyllaea. While the support for Loxonia and Stauranthera is moderate, the relationship of Whytockia and Monophyllaea is very strongly supported (BS = 100%; JK = 100%; DI = 13). Apart from the somewhat surprising (but well-substantiated) isolated position of Rhynchoglossum, the results are in perfect accordance with the relationships worked out earlier on grounds of architectural and floral characters. Especially remarkable is the predicted coherence between the morphologically and geographically different genera Whytockia and Monophyllaea.

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