Ingrid Koch

Indole alkaloids from Rauvolfia bahiensis A.DC. (Apocynaceae).

Four indole alkaloids, 12-methoxy-N(a)-methyl-vellosimine, demethoxypurpeline, 12-methoxyaffinisine, and 12-methoxy-vellosimine, in addition to picrinine, vinorine, raucaffrinoline, normacusine B, norseredamine, seredamine, 10-methoxynormacusine B, norpurpeline and purpeline, were isolated from the bark or leaf extracts of Rauvolfia bahiensis.

As Apocynaceae s. str. da região de Bauru, São Paulo, Brasil

The present study describes a survey of the Apocynaceae in different types of vegetation, in the region of Bauru, in the Center-West of Sao Paulo State. Of the 25 species encountered, distributed into 15 genera, representation ranges as follows: Forsteronia G. Mey, five species; Aspidosperma Mart., four species; Mandevilla Lindl., three species; Prestonia R. Br., two species; and Condylocarpon Desf., Hancornia Gomez, Himatanthus Willd. ex Roem. et Schult., Macrosiphonia Mull. Arg., Mesechites Mull. Arg., Odontadenia Benth, Peltastes Woodson, Rhodocalyx Mull Arg., Secondatia A. DC., Tabernaemontana L. and Temnadenia Miers, one species each. In addition to both distribution data, and flowering and fruiting times, identifications keys, descriptions and illustrations of the species are presented.

Reproductive biology and functional aspects of the floral morphology of Rauvolfia sellowii Mü ll. Arg. (Apocynaceae; Rauvolfioideae) — a report of dioecy in Apocynaceae

KOCH, I., BITTRICH, V. & SUMIKO KINOSHITA, L.: Reproductive biology and functional aspects of the floral morphology of Rauvolfia sellowii Mu ll. Arg. (Apocynaceae; Rauvolfioideae) — a report of dioecy in Apocynaceae. — Bot. Jahrb. Syst. 124. 83‐104. — ISSN 0006‐ 8152. During studies on the reproductive biology of Rauvolfia sellowii Mu ll. Arg. the occurrence of functional dioecy was verified. This is the first case of dioecy in Apocynaceae s. str. demonstrated unequivocally. The occurrence of gynodioecy in R. vomitoria Afzel. is also demonstrated and its occurrence in Carissa grandiflora (E.Meyer) A.DC. confirmed. Our data reveal another case of a taxon described as having hermaphroditic flowers that has in fact functionally dioecious flowers. Behaviour of the pollinators and small populations might have favoured the development of dioecy in R. sellowii to avoid endogamic depression. The nonfunctional flower organs are particularly interesting: male flowers show all female structures, including well-developed ovules. Only callose deposition in the ovules and the absence of fruit development reveal their nature. Female flowers have empty anthers. Such organs still play an important role for the reproductive mechanism and we believe that this is responsible for their persistence. Although the possibility that the evolutionary time elapsed since the development of dioecy was insufficient for their suppression cannot be completely ruled out. Although it has been suggested that stigmatic receptivity is restricted to a region below the circular scraper structure at the base of the style head, pollen tube growth demonstrated that the median secretory part is also receptive in these cases. Secondary sexual characters and mechanisms of the pollination process are also discussed. Earlier studies dealing with the functional importance of floral structures during pollination are briefly reviewed.

Systematics and character evolution of Vinceae (Apocynaceae)

Vinceae comprises 9 genera and about 153 species. The genera differ greatly in a number of morphological traits, especially those relating to fruit and seeds, which resulted in their placement in different tribes and/or subtribes by earlier taxonomists. Here, 378 new chloroplast DNA sequences from 98 species from 5 tribes of the rauvolfioid grade were analyzed phylogenetically to test the monophyly of Vinceae, its 6 subtribes, and constituent genera, as well as the sectional treatments of Rauvolfia, and to find morphological synapomorphies for major clades. Vinceae, as currently circumscribed, was found to be monophyletic as were four of the six subtribes. Kopsia and Ochrosia were confirmed as successive sister groups to the rest. All nine genera currently recognized in the tribe were resolved as monophyletic, Laxoplumeria and Tonduzia for the first time. The broad circumscription of Petchia and Ochrosia proposed by previous authors was supported. The pantropical genus Rauvolfia is divided into two major lineages: one comprised entirely of paleotropical species, and the other the neotropical species, a recurring geographic pattern in the family. Surprisingly, the Hawaiian species of Vinceae have probably arisen by two different trans-oceanic routes, either by long-distance dispersal from Australasian (Ochrosia spp.) or Caribbean (Rauvolfia sandwicensis) ancestors. Within Rauvolfia, most of the sections, series and subseries recognized in previous classifications are paraphyletic. Only 2 of the 14 sections of Rauvolfia proposed by Pichon and 1 of the 11 sections proposed by Rao that are not monospecific were found to be monophyletic. Mapping of 30 morphological characters onto the molecular tree identified an unlobed upper wreath on the style head as an unambigous synapomorphy characterizing the tribe as well as synapomorphies for each of its genera. The two earliest-branching genera, Kopsia and Ochrosia, have dextrorse corolla lobe aestivation, in contrast to the sinistrorse corollas of the other Vinceae and the great majority of genera throughout the rauvolfioid grade. Drupes have arisen in parallel at least three times within Vinceae. The adaptations of the endocarp for water dispersal are possibly ancestral in the tribe, and the observed morphological differences between the drupaceous fruits of Kopsia/Ochrosia versus Petchia and Rauvolfia may be due to their abiotic versus biotic dispersal mode, respectively.

Taxonomic Novelties in Rauvolfia (Apocynaceae, Rauvolfioideae) from Brazil

ABSTRACT Descriptions and illustrations of three new Brazilian species of the genus Rauvolfia L. (Apocynaceae, Rauvolfioideae), R. capixabae I. Koch & Kinoshita-Gouvêa, R. gracilis I. Koch & Kinoshita-Gouvêa, and R. pruinosifolia I. Koch & Kinoshita-Gouvêa, are presented. Rauvolfia blanchetii A. DC., R. mollis S. Moore, and R. divergens Markgraf are newly synonymized under R. ligustrina Willdenow, R. pernambucensis Emygdio under R. moricandii A. DC., and R. sessilifolia S. Moore under R. weddelliana Müller Argoviensis. Lectotypes for R. blanchetii and R. ternifolia Kunth are designated; furthermore, comments to clarify the complicated typification of R. ligustrina and R. ternifolia are presented.

The impacts of landscape composition, marginality, and climatic stability on the patterns of endemism of Cerrado woody plants

Aim: Although various theories have been proposed to explain the outstanding endemism of plants in the Cerrado, four hypotheses about the mechanisms of diversification and distribution are most supported: (1) plateau/valley, (2) stable/unstable climate, (3) core/peripheral distribution, and (4) soil fertility. The first argues that plateaus harbor more ancient lineages than valleys and therefore presents higher endemism. The second theory suggests that climatic stable environments maintained more paleoendemic species. The third scenario attributes the distribution of endemism to gradients of conditions available to locally adapted species and predicts higher endemism in nuclear than in marginal areas. The last theory suggests that lower fertility soils account for higher endemism due to the habitat specialization of its species. We compared endemism patterns with the predictions of each theory to discuss their importance. Location: Brazil. Time period: Quaternary. Major taxa studied: Angiosperms. Methods: We mapped the endemism using records of 311 plant species of the Cerrado and applied spatial analysis and distribution models to summarize the importance of each predictor of endemism. Results: We identified 28 areas in which the higher endemism of Cerrado plants were concentrated and presented a map of its distribution. We found correlations among endemism, climate stability, elevation, and marginality, which supported the plateau/valley, core/peripheral, and stable/unstable hypotheses. No association between soil fertility and endemism was detected. We propose that plateaus are more stable climatic environments, and this characteristic along with their elevation and centrality are predictive of endemism. Main conclusions: We concluded that most of the endemism is concentrated in overlapping areas of stability of species, which are concentrated in higher elevation central regions. Soil fertility was not linked to endemism. We recommend that central plateaus in the Cerrado require special attention in conservation to optimize the protection of endemic species in the biome. Keywords: Biogeography, Community ecology, Species distribution modeling, Last Glacial Maximum, Savanna, Plateaus, Valleys.Aim Although various theories have been proposed to explain the outstanding endemism of plants in the Cerrado, four hypotheses about the mechanisms of diversification and distribution are most supported: (1) plateau/valley, (2) stable/unstable climate, (3) core/peripheral distribution, and (4) soil fertility. The first argues that plateaus harbor more ancient lineages than valleys and therefore presents higher endemism. The second theory suggests that climatic stable environments maintained more paleoendemic species. The third scenario attributes the distribution of endemism to gradients of conditions available to locally adapted species and predicts higher endemism in nuclear than in marginal areas. The last theory suggests that lower fertility soils account for higher endemism due to the habitat specialization of its species. We compared endemism patterns with the predictions of each theory to discuss their importance. Location Brazil. Time period Quaternary. Major taxa studied Angiosperms. Methods We mapped the endemism using records of 311 plant species of the Cerrado and applied spatial analysis and distribution models to summarize the importance of each predictor of endemism. Results We identified 28 areas in which the higher endemism of Cerrado plants were concentrated and presented a map of its distribution. We found correlations among endemism, climate stability, elevation, and marginality, which supported the plateau/valley, core/peripheral, and stable/unstable hypotheses. No association between soil fertility and endemism was detected. We propose that plateaus are more stable climatic environments, and this characteristic along with their elevation and centrality are predictive of endemism. Main conclusions We concluded that most of the endemism is concentrated in overlapping areas of stability of species, which are concentrated in higher elevation central regions. Soil fertility was not linked to endemism. We recommend that central plateaus in the Cerrado require special attention in conservation to optimize the protection of endemic species in the biome.

Fruit production along roads and footpaths in an Atlantic rain forest area

ABSTRACT Background: Pathways (footpaths and roads) in forests are associated with edge effects, affecting forest structure and composition and associated wildlife. However, little is known about how edge effects along pathways may impact the dynamics of fruit production and their availability for frugivores. Aim: We related pathway width as a proxy for edge effects to fruit production. Our underlying hypothesis was that pathway width would be positively related to fruit production. Methods: We observed fruit production along three pathways of different widths – 2, 10 and 20 m wide – and in a control area of undisturbed forest in an Atlantic rain forest stand monthly over a 2-year period. Results: The number of species and individuals-bearing fruit was higher along the wider pathways than along the narrowest pathway and in the control area. The amount of zoochorous fruits was higher in the control area than along pathways, and the widest pathway had higher non-zoochorous fruits production. Fruiting peaks occurred along pathways, while fruiting in the control area was aseasonal. Conclusions: Pathway width is related to fruit type and its quantity and temporal availability. These effects extend towards the forest interior beyond 35 m. The presence of paths affects food resources for frugivores and thus can contribute to reconfiguring the spatio-temporal distribution of the fauna.

Explaining Ovule Sterility in Rauvolfia L. (Apocynaceae)

Premise of research. Approximately 5% of Gentianales are estimated to be dioecious—mainly the members of Rubiaceae, Gentianaceae, and Loganiaceae. In Apocynaceae, there exists a report of cryptic dioecy for Rauvolfia sellowii Müll. Arg. Some individuals have flowers with empty anthers (pistillate), and some have flowers with ovules that do not develop into seeds (staminate). As the staminate flowers in this species appear to be hermaphrodite, embryology could help explain how ovule sterility occurs. We aim to identify how the development of ovules, megasporogenesis, and megagametogenesis occur in Rauvolfia species with different reproductive strategies and thus to determine the process that leads to ovule sterility in the staminate flowers of R. sellowii. Methodology. Floral buds and flowers were collected, fixed in Karnovsky solution for 48 h, dehydrated, embedded, sectioned, and stained with a 0.05% toluidine blue aqueous solution. Pivotal results. The species studied have two ovules per locule, except for R. sellowii, whose carpels each have up to four ovules. The ovules are anatropous, unitegmic, and tenuinucellate. The single archesporial cell differentiates directly into the megaspore mother cell, which then gives rise to a linear or T-shaped tetrad. The chalazal megaspore is functional and develops into a Polygonum type of megagametophyte. In the staminate flowers of R. sellowii, megasporogenesis is similar, but most megaspores may degenerate. When the megaspores develop, the megagametophyte can degenerate. If the megagametophyte is formed at maturity, it is narrower than those observed in the hermaphrodite flowers of the other species and shows evidence of cell death. Conclusions. Sterility of ovules in the staminate flowers of R. sellowii is due to the nonformation of functional megagametophytes but does not affect ovule formation, per se. This phenomenon can lead to a misinterpretation of the staminate flowers as being hermaphrodite. We also discuss a possible lability in the sexual expression of R. sellowii.

Anther wall and pollen development in two species of Rauvolfia L. (Apocynaceae)

Although dioecy and gynodioecy are widely reported in Gentianales, they are rare in Apocynaceae, with reports for only three species. In these species, the pistillate flowers have empty anthers. To understand how this process occurs, it is important to gather information about the formation of anthers and pollen grains, but studies on the embryology of Apocynaceae are scarce and restricted. Here, we investigate anther wall and pollen grain development and the processes leading to pollen grain absence in R. vomitoria, a gynodioecious species. We compare it with R. weddelliana, a species with hermaphrodite flowers. To do so, the flowers of both species were collected at several developmental stages and processed using usual anatomical techniques. Mature pollen grains were analyzed via scanning electron microscopy. In both species, the anthers are tetrasporangiate, and the anther wall development is of the dicotyledoneous type. The tapetum is secretory, and the endothecium has fibrous thickenings. The tetrad of microspores is tetrahedral as a result of simultaneous cytokinesis. Each pollen grain is tricolpate, two celled, oblate, and smooth. Small perforations occur in the equatorial axis of the pollen only in R. weddelliana. Thick margins occur in the colpi of both species. Surprisingly, when the pistillate flowers of R. vomitoria, which came from the same population in which gynodioecy was reported, were analyzed, fertile anthers were found during this flower season. The only evidence of the sterility was the presence of some sterile microsporangia. Our results indicate that R. vomitoria may exhibit sexual lability.

Development and cross-validation of microsatellite markers for Rauvolfia weddeliana Müll.Arg. (Apocynaceae) species complex

AbstractRauvolfia weddeliana is an endemic species restricted to plateau landscapes in South American savannahs. Rapid loss of habitat and expansion of agriculture in Central-West Brazil have critically reduced the original extent of savannahs, representing a major threat to its biotic diversity. Due to the discontinuous distribution of R. weddeliana and the vulnerability of its habitats, it is crucial to estimate the genetic diversity of remaining populations. The application of microsatellite markers is a useful approach with relative low cost and high informative potential for studies related to conservation genetics and population genetics. The development of specific libraries for endangered species may aid future studies about the connectivity of populations, reproductive biology, and genetic diversity. We developed microsatellite markers for R. weddeliana and tested the transferability of the markers to a closely related species, R. gracilis. Ten microsatellite markers were identified, and a set of primers for their amplification is presented. Most identified motifs were dimers, with lengths from 18 to 74 base pairs. Nine markers presented high informative potential (PIC > 0.5). The set of markers developed in this study will support further investigations in population genetics of R. weddeliana and possibility of closely related species.