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Abstract Light energy is essential for carbon metabolism in plants, as well as controlling the transport of metabolites between the organs. While terrestrial plants have a distinct structural and functional separation between the light exposed aerial parts and the non-exposed roots, epiphytic plants, such as orchids, have shoots and roots simultaneously fully exposed to light. The roots of orchids differ mainly from non-orchidaceous plants in their ability to photosynthesize. Since the roots of Catasetum fimbriatum can synthesize auxin which is acropetally transported to the shoot region, we decided to investigate whether: (1) light treatment of C. fimbriatum roots raises the auxin levels in the plant; and (2) distinct auxin concentrations can change the source-sink relationships, altering the amounts of sugars and organic acids in leaves, pseudobulbs and roots. Among the organs studied, the roots accumulated the highest concentrations of indole-3-acetic-acid (IAA); and when roots were exposed to light, IAA accumulated in the leaves. However, when polar auxin transport (PAT) was blocked with N -(1-Naphthyl)phthalamic acid (NPA) treatment, a significant accumulation of sugars and organic acids occurred in the pseudobulbs and leaves, respectively, suggesting that auxin flux from roots to shoots was involved in carbon partitioning of the aerial organs. Considering that C. fimbriatum plants lose all their leaves seasonally, it is possible the roots are a substituting influence on the growth and development of this orchid during its leafless period. Highlights • Catasetum fimbriatum roots receives light in its natural epiphytic environment. • The root-light condition changed the auxin transport from the roots to the shoot. • Changing the polar auxin transport resulted in modifications in carbon partitioning. • Source-sink relationships was light-induced in an auxin dependent manner. [ABSTRACT FROM AUTHOR]

Catasetum macrocarpum is an epiphytic orchid that has been subjected to strong environmental pressure in the state of Tocantins. This investigation aimed at studying the germination, growth and morpho-anatomical development of C. macrocarpum under in vitro conditions. The effects of three culture media on the in vitro germination and on the multiplication and growth of 90-day-old seedlings were studied: Murashige & Skoog (full- and halfstrength), Knudson C, and Vacin & Went. The effects of different concentrations of benzyladenine (BA) and naphthaleneacetic acid (NAA) on the multiplication and growth of 120-day-old plants were evaluated. Anatomical studies were conducted on protocorms at different developmental stages. Acclimatization was also carried out. Knudson C was the best medium for seed germination whereas Vacin & Went promoted the greatest protocorm development. Half-strength Murashige & Skoog was the most effective medium for seedling multiplication and growth. The results revealed that 1 mg L-1 BA was the best treatment for shoot proliferation and leaf production. NAA at 0.5 mg L-1 strongly favored root formation. The anatomical study revealed that the early stages of C. macrocarpum development do not always coincide with the morphological phases described. The acclimatization of C. macrocarpum plants provided successful results regarding plant survival. [ABSTRACT FROM AUTHOR]

Abstract: The neotropical orchid genus Catasetum embraces about 180 species that produce perfume as reward for pollinators (i.e. male euglossine bees). Among the ca. 1000 perfume‐rewarding plants, Catasetum species are the best studied with respect to their natural history. Nevertheless, the pollination ecology of most species (> 80%) remains unknown. Here, we investigated the pollination ecology and floral scent chemistry of C. galeritum, a rare species endemic to the poorly investigated Brazilian Amazon. Flowers of C. galeritum were visited only by male bees of Eufriesea superba. Its perfume bouquet was composed of six volatiles, with 1,4‐dimethoxybenzene accounting for about 85% of the total scent discharge. Curiously, this compound is a potent attractant of more than 40 euglossine species. The absence of euglossine species other than Ef. superba on flowers of C. galeritum might be, therefore, be mediated by a modifier effect of another compound(s) in its floral scent bouquet. [ABSTRACT FROM AUTHOR]

The Neotropical genus Catasetum is one of the most notable orchids because of its unusual reproductive strategy. In contrast to most orchids, all of the ca. 170 Catasetum species have sexually dimorphic, unisexual flowers involved in a highly specialized pollination mechanism. Flowers of Catasetum produce strong floral perfumes that act as both attractant and reward for male euglossine bees. While collecting perfumes, euglossine males may remove the pollinarium from a male flower and subsequently deposit it in the stigmatic slit of a female flower, resulting in pollination. Here we present an overview of the existing literature on floral scent chemistry and pollinators of Catasetum and add new reports on the pollinators of some species. We provide some insights into the ecology and evolution of floral scents in the genus Catasetum and suggest directions for future research. We hope this review will stimulate research not only on the ecology and evolution of Catasetum but also of the about 1000 species of fragrance-rewarding plants that are found in the Neotropics. [ABSTRACT FROM AUTHOR]

Floral volatile organic compounds (VOCs) are important signals in plant-pollinator communication and thus subjected to olfactory-mediated selection. Occasionally, phylogenetically unrelated plant species will converge towards similar patterns of floral scent signalling to harness pollinators, representing a common adaptive pollination niche. Catasetum cernuum and Gongora bufonia , epiphytic orchids that are native to the Atlantic Forest of southeastern South America, are exclusively pollinated by male Eufriesea violacea orchid-bees; we hypothesised that the two species have converged towards similar floral scent compositions to effectively attract these particular fragrance-seeking floral visitors. The similarity of the chemical composition of floral scent samples obtained through headspace collection was tested using multiple approaches of multivariate analyses (Multiple Response Permutation Procedure—MRPP). According to MRPP, floral scents of C. cernuum and G. bufonia are significantly different. Additionally, the floral scents of C. cernuum and G. bufonia present ( E )-β-ocimene and ( E )-epoxyocimene as their major compounds, respectively. ( E )-β-ocimene is a common constituent of floral scents from euglossine-pollinated orchids, while ( E )-epoxyocimene is quite rare in orchids’ floral scents and it is found in only a few other species which occur outside the distribution range of C. cernuum , G. bufonia and E. violacea . However, 12 out of the 34 identified VOCs, including ( E )-β-ocimene and ( E )-epoxyocimene, are shared between both species. Therefore, we assume that both ( E )-β-ocimene and ( E )-epoxyocimene, either alone or mixed with other floral VOCs, play a major role in the specific association between these two orchids and their exclusive euglossine pollinator. [ABSTRACT FROM AUTHOR]

Until now, Catasetum confusum G.A. Romero- González was known from the states of Goiás, Mato Grosso and Tocantins. The present study extends the distribution of this species to the states of Bahia and Piauí, as well as the Federal District, based on herbarium specimens deposited at CEN, RB, UFMT and UPCB. Following IUCN criteria, C. confusum is Endangered due to its area of occupancy, geographic distribution and habitat quality, showing the importance of these new records. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The baridinos have gained importance in agriculture; however, many of them are yet to be described, as is the case for those affecting orchids. It is for this reason that the aim of this research was to identify the insect causing the wilting of petals on orchids belonging to the Catasetum integerrimum species at a site at La Estanzuela, municipality of Emilian Zapata, and El Espinal, municipality of Naolinco, in the state of Veracruz, Mexico. Orchids of the species C. integerrimum in specimens with flowers affected were monitored, as insects cause damage to these at the time of flowering. Thus, according to the morphological characteristics of larvae and adults and of the male and female genitals observed in vegetative material, as well as larvae and adults present on the flowers, it was confirmed that the species of curculionid that attacks the orchid is Stethobaroides nudiventris Champion, 1907. This is the first report of this curculionid as the agent causing wilting on C. integerrimum petals. [ABSTRACT FROM AUTHOR]

In this paper we report the discovery of Catasetum planiceps, in the Serra da Ibiapaba, as a new and important event for the flora of Ceará, Brazil. The species was recorded growing as a rupicolous herb in vegetation called 'Macambiral', which is an area of 'brejo forest', in the Serra da Ibiapaba in the municipality of Ipueiras. The vegetation in this area is a mixture of semi-deciduous tropical moist forests and 'carrasco' vegetation, forming an important ecotone in the caatinga vegetational domain. Collected material was deposited in the EAC and UFMT herbaria and a sample was sent to the DNA bank of the Laboratório de Sistemática e Ecologia Molecular de Plantas of the Universidade Federal do Paraná (Curitiba, Paraná State, Brazil). This new record is of great importance because the type of habitat in which it was registered is very different from that originally described for this species. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Catasetum is a neotropical orchid genus that comprises about 160 dioecious species with a remarkable sexual dimorphism in floral morphology. Flowers of Catasetum produce perfumes as rewards, which are collected only by male euglossine bees. Currently, floral scents are known to be involved in the selective attraction of specific euglossine species. However, sexual dimorphism in floral scent and its eventual role in the pollination of Catasetum species have never been investigated. Here, we have investigated the pollination of Catasetum uncatum and asked: (1) Is floral scent a sexual dimorphic trait? (2) Does pollinarium removal/deposition affect scent emission? (3) Does sexual dimorphism in floral scent and changed scent emission have implications with regard to the behaviour of the pollinators? The frequency and behaviour of floral visitors were observed in non-manipulated flowers (both flower sexes) and in manipulated flowers (pistillate only) in which pollinaria were deposited. Scents of staminate and pistillate flowers (both manipulated and non-manipulated) were collected by using dynamic headspace methods and analysed chemically. Electrophysiological analyses were performed to detect compounds triggering antennal depolarisation in the euglossine species. C. uncatum is pollinated mainly by males of Euglossa nanomelanotricha . Pollinators were more frequent in pistillate than in staminate inflorescences. Bees approaching staminate flowers frequently flew away without visiting them, a behavioural pattern not observed in pistillate flowers. In the chemical analyses, we recorded 99 compounds, 31 of which triggered antennal depolarisation in pollinators. Multivariate analyses with the electrophysiological-active compounds did not detect differences between the scent composition of staminate and pistillate flowers. Pollinarium removal or deposition resulted in diminished scent emission within 24 h in staminate and pistillate flowers, respectively. Surprisingly, bees discriminated pollinated from non-pollinated pistillate flowers as early as 2 h after pollination. The rapid loss in the attractiveness of flowers following pollinarium removal/deposition can be interpreted as a strategy to direct pollinators to non-pollinated flowers. We have found no evidence that euglossine males discriminate staminate from pistillate flowers by means of floral scent. Instead, we speculate that bees use visual cues, such as sex dimorphic traits, to discriminate flowers of different sexes. Together, our results provide interesting insights into the evolution of floral signals in gender-dimorphic species and into its significance in plant reproductive biology. [ABSTRACT FROM AUTHOR]

The State of Rondônia is rich in species of Catasetum that are still undervalued, which presents a major challenge in the preparation of a map that shows the distribution and all occurrences of the species of the genus. As a result of our studies, four new records are presented for the State of Rondônia and a new natural hybrid is described and illustrated. Samples of all species were collected for DNA extraction (aliquots kept in the Total DNA Bank of Plants UFPR - UPCB-DNA) and vouchers deposited at the herbaria UFMT and the RB. [ABSTRACT FROM AUTHOR]

The epiphytic habitat is potentially one of the most stressful environments for plants, making the effective developmental control in response to external cues critical for epiphyte survival. Because ethylene mediates several abiotic stresses in plants, here, we have examined the ethylene influence in both shoot and root systems of the epiphytic orchid Catasetum fimbriatum. Under controlled conditions, ethylene production was quantified during an entire growth cycle of C. fimbriatum development in vitro, while treatments modulating either ethylene concentration or perception were carried out over the early growth phase of these plants. After treatments, growth measurements and histological features were studied in both shoot and root tissues. Ethylene production showed a decreasing trend over the period of organ elongation; however, it increased considerably when leaves were shed, and a new axillary bud was initiating. The early exposure of young plants to higher concentrations of ethylene triggered morphogenic responses that included root hair formation instead of velamen, and a combination of inhibitory effects (decreases in both stem enlargement and cellular/organ elongation) and inductive effects (increases in leaf and root formation, bud initiation and cellular thickening) on plant growth, which favored biomass allocation to roots. Conversely, inhibition of ethylene perception over the plant growth phase generally resulted in the opposite morphogenic responses. Our data indicate that periodic variations in ethylene concentration and/or sensitivity seem to modulate several developmental features in shoot and root systems of C. fimbriatum which could have adaptive significance during the growing phase of this epiphytic orchid. [ABSTRACT FROM AUTHOR]

Mitotic chromosomes of 12 species ofCatasetumwere assessed to contribute with the karyotypic study of the subtribe Catasetinae (Orchidaceae), expanding the knowledge of this group in terms of chromosomes and supporting its taxonomic and evolutionary analysis. The species are maintained in cultivation in the greenhouse of the Department of Plant Biology/IB/UNICAMP and in the “Orquidário Frederico Carlos Hoehne” of the Botanical Garden of São Paulo. Chromosome counts ranged from 2n = 54 to 2n = 108. Karyotypes were prepared for all species studied, in which there was a predominance of metacentric chromosomes and some submetacentric ones. The chromosome size ranged from 0.5 to 4.9 μm, the total chromosome length ranged from 34.7 to 78.7 μm and the asymmetry index TF% ranged from 21.2 to 42.3. The results obtained so far favor the taxonomy of the genus, allowing to distinguish species with very similar external morphology. [ABSTRACT FROM AUTHOR]

The State of Rondônia is rich in species of Catasetum that are still undervalued, which presents a major challenge in the preparation of a map that shows the distribution and all occurrences of the species of the genus. As a result of our studies, four new records are presented for the State of Rondônia and a new natural hybrid is described and illustrated. Samples of all species were collected for DNA extraction (aliquots kept in the Total DNA Bank of Plants UFPR - UPCB-DNA) and vouchers deposited at the herbaria UFMT and the RB. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Biociencias is the property of Revista Brasileira de Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new species of CatasetumRich. ex Kunth (Orchidaceae), Catasetum apolloiBenelli & Grade, from the municipality of Carlinda in the State of Mato Grosso, Brazil is described and illustrated. The plant was discovered in a pasture near the Teles Pires River growing epiphytically under the palm Maximiliana regiaMart. A discussion and consideration of possible related species is presented. [ABSTRACT FROM AUTHOR]

Abstract Spatial and temporal genetic structures were examined across sites on islands and mainland (continuous forest) populations of an epiphytic orchid, Catasetum viridiflavum , using 17 polymorphic allozyme loci. I tested whether patches on islands or at mainland sites comprised small local populations or a large population. Low among population differentiation was observed across the landscape suggesting that the species-specific pollinator and tiny wind-dispersed seeds maintain interconnections among distant patches. Temporal genetic structure among stage classes, and among breeding individuals are important components of the maintenance of genetic variation in this orchid. The natural history of this species including small breeding populations, probable high frequency of mating among relatives, and the high rates of seed movement among sites contribute to the high F IS . These data show that physically isolated patches in this epiphytic orchid comprise a single larger genetic population, which is independent of the physical distances among sites. Although quite different in ecological and life history characteristics, the genetic structure of this orchid demonstrates a pattern similar to temperate and tropical trees in fragmented landscapes. [ABSTRACT FROM AUTHOR]

The effects of either organic (urea and glutamine) or inorganic nitrogen forms (nitrate and ammonium) on dry matter accumulation in shoots and roots and on nitrogen assimilatory enzyme activities were studied in two Catasetum fimbriatum genotypes. Both genotypes, which had inverse patterns of dry matter partitioning between shoots and roots, were aseptically incubated in gelled culture media containing 6 mol m−3 of nitrogen and incubated in growth chamber for 30 and 60 days. In vivo nitrate reductase, glutamine synthetase, glutamate dehydrogenase activities as well as free ammonium contents were determined in shoots and roots of plants grown in four different nitrogen sources. Nitrogen assimilatory enzyme activities showed the highest values in the genotype that accumulated dry matter predominantly in the shoots. The nitrogen sources supplied affected dry matter accumulation in shoots and roots of both C. fimbriatum genotypes; however, they were not enough to change the characteristic pattern of dry matter partitioning of each genotype. On the other hand, the differences in the root/shoot ratio found among nitrogen treatments were relatively higher in the genotype that directed dry matter mainly to roots than in the genotype that allocates biomass to shoots. Our results suggest that NADH-dependent glutamate dehydrogenase plays an important role in ammonium assimilation in C. fimbriatum plants, particularly in the root system. Nitrogen metabolism and the dry matter partitioning of the two genotypes are discussed. [Copyright &y& Elsevier]

Examines the occurrence of Sphenospora kevorkianii on the orchid Catasetum fimbriatum in Brazil. Presence of powdery mass of urediniospores; Morphological features of the fungus; Abundance of dark orange coloured oil droplets.