Towards a unified terminology for angiosperm reproductive systems

Angiosperms display an enormous diversity of forms, functions and strategies when it comes to reproduction. This multiplicity has been translated into several terminological concepts and contexts, which have facilitated further research. On the other hand, the use of terms that address the reproduction of flowering plants has been shown to be inconsistent in the literature, complicating communication among specialists. Key terms, such as “reproductive system”, “mating system” and “sexual system”, among others, have been frequently cited as synonyms, and even used in different circumstances. This review proposes to establish a consistent nomenclatural classification in the field of angiosperms reproductive biology in order to facilitate communication among researchers. Specific terms related to angiosperm reproduction are conceptualized and distributed into five general systems: four related to sexual reproduction (sexual, floral, incompatibility and mating systems); and one related to asexual reproduction (apomictic systems). Our proposal is not to establish a natural classification, but rather to provide a general overview of the main concepts that were grouped here in an artificial and functional manner. Our aim is to advance the field of reproductive biology of angiosperms with consistent and well-defined applications of relevant terminologies

Reproductive aspects of orchids in Veredas of the Cerrado

The Veredas wetlands are unique environments in the Cerrado biome, harboring high diversity and providing important ecosystem services. These environments are particularly diverse in Orchidaceae. In this thesis, we study the reproductive biology of endangered orchids that occur in Veredas wetlands to demonstrate the diversity of processes and the potential for generating knowledge that these environments provide. Cyrtopodium hatschbachii is a species primarily pollinated by bees, but with low fruit set rates, which may even be null in some years. However, we demonstrate in the first chapter how herbivory and rainfall, two factors that are detrimental when considered separately, can together facilitate autogamy and promote reproductive assurance in this species. Phragmipedium vittatum is a lady’s slippery orchid that traps pollinators in order to reproduce. In the second chapter, we demonstrate the various strategies that these flowers adopt to enable successful pollination, from pollinator capture, through the intrafloral movements they are forced to make, until pollen transfer during their exit from the flower. To do so, P. vittatum uses an aphid mimicry system that deceives gravid females of Syrphidae dipterans during flower entry and exit, as they are looking for oviposition sites where their aphidophagous larvae will feed on. Using also P. vittatum as model, we found that it is a unique species in the world as it presents intrapopulation variation in floral resupination. This process refers to the twist of approximately 180º that occurs in some flowers before or during anthesis, which makes them upside down. In the third chapter, we show that approximately 10% of the flowers in the population do not resupinate. We experimentally tested the role of resupination in the process of reproduction and found that only flowers with the lip facing downward have male and female reproductive success, when compared to flowers with the lip positioned upward and sideward. These results are important because they corroborate that the evolution of resupination is related to pollination success, with the lip acting as a landing platform or trap and the column facing downward promoting precise pollen deposition. Finally, in the fourth chapter, we demonstrate that the probability of flowers failing to resupinate is negatively related to their weight. This is the first time that flower resupination has been demonstrated as being a weight dependent process. In short, these results show the diversity of life histories that these organisms threatened by extinction can tell us, as well as their potential for generating detailed knowledge. Thus, the conservation of these species and their respective environments is extremely important for the maintenance of such processes and interactions, which are certainly associated with an equilibrated environment that provides several ecosystem services.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorTese (Doutorado)As Veredas são ambientes únicos do bioma Cerrado, sendo responsáveis por abrigar grande diversidade e prover importantes serviços ecossistêmicos. Esses ambientes são particularmente diversos em Orchidaceae. Nessa tese, nós estudamos a biologia reprodutiva de orquídeas ameaçadas que ocorrem em Veredas com o intuito de demonstrar a diversidade de processos e o potencial de geração de conhecimento que esses ambientes abrigam. Cyrtopodium hatschbachii é uma espécie primariamente polinizada por abelhas, mas que apresenta taxas de frutificação baixas e até ausentes em alguns anos. Entretanto, nós demonstramos no primeiro capítulo como a herbivoria e a chuva, dois fatores que são detrimentais em separado, podem juntos facilitar a autogamia em uma planta e promover segurança reprodutiva. Phragmipedium vittatum é uma orquídea sapatinho que, para se reproduzir, aprisiona os polinizadores em seu interior. No segundo capítulo, nós demonstramos as várias estratégias que essas flores adotam que permitem o sucesso da polinização, desde a captura do polinizador, passando pelos movimentos intraflorais que eles são forçados a fazer, até a transferência de pólen e sua saída da flor. Para tanto, P. vittatum usa um sistema de mimetismo de afídeos que engana fêmeas grávidas de dípteros Syrphidae durante a entrada e saída da flor, já que elas estão a procura de sítios para oviposição onde suas larvas predadoras de afídeos irão se alimentar. Ainda estudando P. vittatum, encontramos que esta espécie trata-se de um modelo único no mundo pois apresenta variação intrapopulacional na ressupinação floral. Este processo trata-se do giro de aproximadamente 180º das flores, o que as deixa com o aspecto de estarem de cabeça para baixo. No terceiro capítulo, nós encontramos que aproximadamente 10% das flores da população não ressupinam. Nós testamos experimentalmente o papel da ressupinação no processo de reprodução das flores e encontramos que apenas flores com o labelo voltado para baixo apresentam sucesso reprodutivo masculino e feminino quando comparadas a flores com labelo posicionado para cima e para o lado. Esses resultados são importantes pois corroboram que a evolução da ressupinação provavelmente esteja relacionada a polinização, sendo que o labelo funciona como uma plataforma de pouso ou armadilha e a coluna voltada para baixo promove a deposição precisa de pólen. Por fim, no quarto capítulo demonstramos que a probabilidade das flores não ressupinarem está negativamente relacionada ao peso das mesmas. Essa é a primeira vez que se é demonstrado que o processo de ressupinação floral é dependente do peso. Em suma, esses resultados mostram a diversidade de diferentes histórias que esses organismos à beira do desaparecimento podem nos contar, bem como o potencial de geração de conhecimento. Assim, a conservação dessas espécies ameaçadas e dos seus respectivos ambientes é de extrema relevância para a manutenção de tais processos e interações, que certamente estão associados a um ambiente equilibrado e provedor de numerosos serviços ecossistêmicos

Segregação espacial horizontal em pequena escala entre duas espécies da família Theridiidae (Araneae)

Mestre em Ecologia e Conservação de Recursos NaturaisNiche theory predicts that coexistence between related species occurring simpatrically is unlikely. Due to the shared phylogenetically conserved ecological attributes, the stronger competitor may exclude competitively the related heterospecific. However, coexistence mechanisms may allow similar species to persist together. In this study, we investigated the coexistence between two related theridiid spider species: Helvivis longicauda and Chrysso intervales. Along riparian habitats of a tropical forest, H. longicauda occurs close to river margins, while C. intervales occurs in higher abundance in further regions, after the zone occupied by H. longicauda, but always in shaded, humid regions. In this sense, this study aimed to investigate this fine-scale horizontal segregation pattern, exploring the relative contribution of different factors in generating the arrangement. Our results confirmed spatial segregation between spider species in both summer and winter, with H. longicauda populations being restricted to river margins and C. intervales to contiguous regions. These species were positively related to the abundance of suitable sites used for web-building and negatively to the relative abundance of fern leaves, which seem to be unsuitable sites. Apparently, spiders also present niche differentiation in the height they build webs, with C. intervales occurring at lower average heights. Helvibis longicauda was the only one infested by fungi and the mortality rates were higher during winter. At this time, we found more C. intervales individuals occupying areas close to the river than we did in summer. Helvibis longicauda trophic niche breadth was wider than that of the heterospecific. However, we did not found differences in prey abundance across distinct distances from the river. Only the temperature was different, increasing away from the river. There were no differences in establishment rates between species in both environments. However, it is still possible that H. longicauda success far from the margins is lower during summer, once transplant experiments were performed during winter, in which temperature did not differ between species zones. Helvibis longicauda was the most common species colonizing potential web-building sites at marginal regions, while C. intervales colonizers were found mainly in areas further away. Agonistic interactions demonstrated that resident spiders present advantage in both intra and interspecific contests, once they remained alone in the web in most contests. Resident spiders effectively defended the web even against larger intruders. However, much larger intruders presented an increase in the probability of remaining in the alien web, sometimes taking it over. Although C. intervales average body mass is higher than that of H. longicauda, this difference seems to represent no effect in C. intervales reaching marginal regions. We hypothesized that capture rates of H. longicauda at further distances is compromised due to high temperature acting on the smaller viscid droplets, reducing adhesiveness. This abiotic factor restricts this species to cooler places. In the vertical axis, both species may potentially occupy the lower sites of the river margins. However, H. longicauda apparently displace C. intervales through asymmetric exploitation competition. The fact that fungi reduced H. longicauda populations functioned as a natural removal experiment and resulted in a competitive release for C. intervales individuals to reach margins, even with H. longicauda still being more abundant at this place

length_prey.csv

<p>Data Set Owner(s):</p> <p>João Custódio Fernandes Cardoso</p> <p>Universidade Federal de Uberlândia, Brazil</p> <p>Post-Graduation student</p> <p>Programa de Pós graduação em Ecologia e Conservação dos Recursos Naturais</p> <p>Universidade Federal de Uberlândia</p> <p>Rua Ceará SN</p> <p>34-91204045</p> <p>[email protected]</p> <p>Marcelo de Oliveira Gonzaga</p> <p>Universidade Federal de Uberlândia, Brazil</p> <p>Key words:</p> <p>Arthropod</p> <p>Sticky traps</p> <p>Spider prey</p> <p>Body length</p> <p>Atlantic Forest</p> <p>Riparian Forest</p> <p>Geographic Reference:</p> <p>South: 24° 15' 55"</p> <p>West: 48° 24' 25"</p> <p>Temporal Coverage:</p> <p>Begin: 2014-02-05</p> <p>End: 2014-02-15</p> <p>File: length_prey</p> <p>Description: Richness and body length of potential spider prey captured via sticky traps positioned in three different level distances according to the river margins (0, 10, 20 m).</p> <p>Methods: Along the Mirante river margins, at Intervales State Park, we collected potential spider prey items by using sticky traps attached to vegetation. We selected five triplets of transects, totaling 15. Each triplet was divided in transects of 0, 10 and 20 meters from the river. Each sticky trap was composed by a plastic sheet (15 x 10 cm) covered with tanglefoot resin (The Tanglefoot Company®, Rapids, Michigan, USA) in one of the sides. A total of six traps were positioned on each transect, totaling 90. Trapped organisms were measured to the nearest 0,01 millimeter by using a caliper attached to a stereomicroscope.</p> <p>Column Headings:</p> <p>transect: Number of transect triplet (1-5) in which traps were positioned</p> <p>distance: Relative distance from the river in which sticky traps were positioned (values in meters)</p> <p>group: Arthropod identification to the nearest taxonomic group.</p> <p>length: body length in millimeters measured with 0,01 accuracy</p

Evolutionary_opinions

Data from the study "Evolutionary thinking among biology students in a third world country"; published in "Evolution Education and Outreach"

Do distylous syntopic plant species partition their floral morphological traits?

Morphological niche partitioning between related syntopic plants that are distylous (with short- and long-styled morphs) is complex. Owing to differences in the heights of stigmas and anthers, each floral morph must place pollen onto two distinct parts of the body of the pollinator. This led us to hypothesize that such partitioning should be more accurate among distylous syntopic species in comparison to combinations with other related plants that do not co-occur. We tested these assumptions using a set of Palicourea (Rubiaceae) species as a model system. We compared the distribution, flowering phenology, floral measurements and reciprocity of sexual organ heights of two syntopic species (Palicourea rigida and Palicourea coriacea) and one non-syntopic congener (Palicourea marcgravii). The three species overlapped in their distributions and flowering periods. The position of sexual organs was, in most cases, partitioned between syntopic populations, with low overlap in anther and stigma heights. However, we found a higher overlap involving the non-syntopic species, especially between Palicourea rigida and Palicourea marcgravii. Additionally, reciprocity of sexual organs was more accurate in intraspecific inter-morph combinations (i.e. legitimate organ correspondence) in comparison to intraspecific intra-morph, interspecific syntopic and interspecific non-syntopic combinations. The partitioning of morphological traits between syntopic species might facilitate the differential placement of pollen on the body of the pollinator and reduce the chances of interspecific interference

Towards a unified terminology for angiosperm reproductive systems

ABSTRACT Angiosperms display an enormous diversity of forms, functions and strategies when it comes to reproduction. This multiplicity has been translated into several terminological concepts and contexts, which have facilitated further research. On the other hand, the use of terms that address the reproduction of flowering plants has been shown to be inconsistent in the literature, complicating communication among specialists. Key terms, such as “reproductive system”, “mating system” and “sexual system”, among others, have been frequently cited as synonyms, and even used in different circumstances. This review proposes to establish a consistent nomenclatural classification in the field of angiosperms reproductive biology in order to facilitate communication among researchers. Specific terms related to angiosperm reproduction are conceptualized and distributed into five general systems: four related to sexual reproduction (sexual, floral, incompatibility and mating systems); and one related to asexual reproduction (apomictic systems). Our proposal is not to establish a natural classification, but rather to provide a general overview of the main concepts that were grouped here in an artificial and functional manner. Our aim is to advance the field of reproductive biology of angiosperms with consistent and well-defined applications of relevant terminologies