Laurence Humeau

University of La Réunion · Department of Biology

Humans are regularly cited as the main driver of current biodiversity extinction, but the impact of historic volcanic activity is often overlooked. Pre-human evidence of wildlife abundance and diversity are essential for disentangling anthropogenic impacts from natural events. Réunion Island, with its intense and well-documented volcanic activity,...

Animal migration is a major driver of infectious agent dispersal. Duck and seabird migrations, for instance, play a key role in the spatial transmission dynamics and gene flow of avian influenza viruses (AIV), worldwide. On tropical islands, brown and lesser noddies (Anous stolidus and Anous tenuirostris) may be important AIV hosts, but the lack of...

Animal migration is a major driver of infectious agent dispersal. Duck and seabirds migrations, for instance, play a key role in the spatial transmission dynamics and gene flows of avian influenza viruses (AIV), worldwide. On tropical islands, brown and lesser noddies ( Anous stolidus and A. tenuirostris ) may be important AIV hosts, but the lack o...

Faunas of oceanic islands have a high proportion of endemic species which contribute to the uniqueness of island communities. Island species are particularly naïve and vulnerable to alien predators, such as cats ( Felis catus ). On large, inhabited islands, where the complete eradication of feral cat populations is not considered feasible, control...

Background Shearwaters (order Procellariiformes) are an excellent study system to investigate the genetic consequences of the co-called “seabird paradox”, as they are able to disperse long distances but many species exhibit natal and breeding philopatry. However, few microsatellite markers are currently available for these taxa, hampering genetic i...

Effective conservation requires maintenance of the processes underlying species divergence, as well as understanding species’ responses to episodic disturbances and long-term change. We explored genetic population structure at a previously unrecognized spatial scale in seabirds, focusing on fine-scale isolation between colonies, and identified two...

Investigations of the genetic structure of populations over the entire range of a species yield valuable information about connectivity among populations. Seabirds are an intriguing taxon in this regard because they move extensively when not breeding, facilitating intermixing of populations, but breed consistently on the same isolated islands, rest...

Psiadia arguta (Asteraceae) is endemic to the island of Mauritius in the Indian Ocean. The species is traditionally used to treat various ailments, such as its use as an expectorant or for the treatment of bronchitis and asthma. Preliminary biological screenings have displayed the antimalarial (Plasmodium falciparum) and anticancer (HeLa human cell...

The Mascarene petrel (Pseudobulweria aterrima ) is a critically endangered seabird endemic to Reunion Island, with an extremely small population suffering several threats. Fifteen polymorphic microsatellite loci were isolated from this species to analyse genetic diversity, estimate contemporary effective population size, search for evidence of a po...

First at-sea distribution (breedin and non-breeding period) and activity for the endemic and critically endangered Mascarene Petrel (Pseudobulweria aterrima)

Although previous studies have reported Leptospira carriage in kidneys and urine of cats, the role of these animals in leptospirosis epidemiology remains poorly understood. Using molecular methods, we investigated Leptospira renal carriage in 172 feral cats from Reunion Island, an oceanic geographically isolated island located in the South West Ind...

We isolate and characterise 16 polymorphic microsatellite loci for the super-abundant, pan-tropical sooty tern (Onychoprion fuscatus), facilitating population genetic studies. In 70 samples from two breeding colonies, the total number of alleles per locus ranged between 5 and 21, observed heterozygosity ranged from 0.143 to 0.942, while estimated n...

Fifteen polymorphic microsatellite loci were isolated from the endangered Barau's Petrel (Pterodroma baraui), endemic to Réunion Island, Indian Ocean, France, facilitating population studies for conservation. In 148 samples from two colonies, the total number of alleles per loci ranged from three to eight, observed heterozygosity ranged between 0.1...

Premise of the study: Polymorphic markers were required for a native tree of the Mascarene Islands, Foetidia mauritiana (Lecythidaceae), to investigate the effects of fragmentation of lowland tropical habitats on tree mating systems and on gene flow. • Methods and Results: Using microsatellite enrichment and next-generation sequencing, we identifie...

In Vanilla species (Orchidaceae), the influence of sexual and asexual mating systems on the spatial structuring of population genetic diversity is understudied. These elements are crucial in restoration program to limit inbreeding depression and to maintain the genetic diversity of natural populations. In the remnant fragments of tropical dry fores...

Backgrounds and aims: Theory predicts that the long-term persistence of plant populations exposed to size reduction can be threatened by a loss of genetic diversity and increased inbreeding. However, several life-history and ecological traits can influence the response to population size reduction. The reproductive patterns, levels of genetic dive...

Population modelling for one of Réunion Island’s endemic seabirds, the Barau’s Petrel (Pterodroma baraui), has highlighted its vulnerability to extinction. Conservation action demands information on its biology during different stages of its life cycle. Whilst most aspects of the species’ terrestrial ecology have been studied, at-sea information is...

Supplementary material, containing detailed descriptions of the molecular sexing, stomach content, and FASA methodological approaches as well as the complete TFA compositions of whole blood, is available as an electronic supplement to this article.

In South Africa, the wild leafless Vanilla roscheri Rchb. f. (Orchidaceae) is distributed only on the banks of the Lake Sibaya in KwaZulu-Natal Coastal Forest in the iSimangaliso Wetland Park. It is the southernmost vanilloid orchid on the African continent and a species of high conservation priority with little understanding of its reproductive bi...

Identifying factors that promote population differentiation is of interest for understanding the early stages of speciation. Gene flow among populations inhabiting different environments can be reduced by geographical distance (isolation-by-distance) or by divergent selection resulting from local adaptation (isolation-by-ecology). Few studies have...

The pollination ecology and breeding system of Trochetia granulata (Malvaceae), an endemic tree species from Réunion were studied. In 2010–2011, compatibility studies were conducted on a total of 154 flowers from 35 different individuals using three different hand pollination treatments: (a) autofertility, (b) self-pollination and (c) cross-pollina...

Dombeya formosa (Malvaceae s. l. or Dombeyaceae), a new species endemic to La Reunion, is described and illustrated. The species is distinguishable by its ovate leaves with round or slightly cordate bases, round to lightly acute apices and glabrescent abaxial surfaces, subulate and persistent stipules, umbellate inflorescences, and acute apices of...

There is a serious lack of information on the genetic diversity and population dynamics of the 110 tropical Vanilla species, although these are keys elements to adjust conservation strategies. Nineteen polymorphic microsatellite markers were developed from two African leafless Vanilla species V. roscheri and V. humblotii to use in population geneti...

Conservation strategies are not possible when there is confusion in the taxonomic status of a group of plants. Such confusion makes difficult for systematic biologists to identify functional biological entities. This is particularly true in the case of species that diversified fast due to adaptive radiation particularly plants from the oceanic isla...

Conservation strategies are not possible when there is confusion in the taxonomic status of a group of plants. Such confusion makes difficult for systematic biologists to identify functional biological entities. This is particularly true in the case of species that diversified fast due to adaptive radiation particularly plants from the oceanic isla...

Orchid species are well known for their highly specialized pollinator interactions. To better understand the reproductive biology of the tropical epiphytic orchid Bulbophyllum variegatum on Reunion, we investigated the floral morphology, breeding system, pollinator diversity, floral scent profile and fruiting success of about 30 individuals in thre...

Sideroxylon majus (Sapotaceae) is an endangered endemic tree of La Réunion Island that has suffered from human actions. It is present in small and isolated populations that encounter severe difficulties to regenerate. To have powerful tools for population genetic studies, we have isolated and characterized 14 polymorphic microsatellite markers from...

This article documents the addition of 277 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Ascochyta rabiei, Cambarellus chapalanus, Chionodraco hamatus, Coptis omeiensis, Cynoscion nebulosus, Daphnia magna, Gerbillus nigeriae, Isurus oxyrinchus, Lates calcarifer, Metacarcinus m...

The inability to flower and produce fruit above 1100 m a.s.l. is an important characteristic of Rubus alcei folius Poiret (Rosaceae), an introduced bramble that has invaded large areas of tropical rain forest on Réunion island. Why does R. alceifolius not fruit in the highlands? It is known that a minimal morphological structure and structural matu...

This article documents the addition of 277 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Ascochyta rabiei, Cambarellus chapalanus, Chionodraco hamatus, Coptis omeiensis, Cynoscion nebulosus, Daphnia magna, Gerbillus nigeriae, Isurus oxyrinchus, Lates calcarifer, Metacarcinus m...

This article documents the addition of 396 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anthocidaris crassispina, Aphis glycines, Argyrosomus regius, Astrocaryum sciophilum, Dasypus novemcinctus, Delomys sublineatus, Dermatemys mawii, Fundulus heteroclitus, Homalaspis plana,...

Correspondance: Molecular Ecology Resources Primer Development Consortium, E-mail: editorial.office@molecol.com

This article documents the addition of 396 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anthocidaris crassispina, Aphis glycines, Argyrosomus regius, Astrocaryum sciophilum, Dasypus novemcinctus, Delomys sublineatus, Dermatemys mawii, Fundulus heteroclitus,Homalaspis plana, J...

Although angraecoid orchids are famous for their spectacular flowers, pollinated by hawkmoths in Madagascar, two species of Angraecum endemic to the Mascarenes (sect. Hadrangis) have atypical unscented and short-spurred flowers that are pollinated by birds. We focused on the pollination and reproductive success of Angraecumbracteosum Balf.f. & S.Mo...

Nine plants from Reunion Island, selected using ethnopharmacology and chemotaxonomy, were investigated for their potential antimalarial value. Thirty-eight extracts were prepared by maceration using CH(2)Cl(2) and MeOH, and were tested for in vitro activity against the 3D7 and W2 strain of Plasmodium falciparum. The most active extracts were then t...

Based on the number of new reports during the last two decades, bacterial blight of onion (Allium cepa) is considered an emerging disease. The causal agent, Xanthomonas axonopodis pv. allii, is pathogenic to several Allium species after inoculation, but outbreaks worldwide have been primarily reported on onion. We describe a unique epidemiological...

This study was led with the aim of providing original antimalarial agents to thwart the parasite drug resistance. Plants not yet explored phytochemically provide a good source of candidates. Reunion flora possesses up to 30% endemic vegetation. Therefore, 9 plants from this island selected using ethnopharmacology and chemotaxonomy, were investigate...

Documenting the floral biology and breeding system of species throughout the Rubiaceae family provides data on the number of times heterostyly and dioecy may have evolved in this large family. The objectives of this paper are to quantify (a) whether Chassalia corallioides, a small tree endemic to La Reunion Island in the Indian Ocean, is another ex...

ABSTRACT Onion, a biennial plant species, is threatened by the emerging, seed-borne, and seed-transmitted Xanthomonas axonopodis pv. allii. Bacterial blight epidemics were monitored in seed production fields over two seasons. Temporal disease progress was different between the two seasons, with final incidence ranging from 0.04 to 0.06 in 2003 and...

The genus Dombeya is an important component of tropical forests in west Africa, Madagascar, and the Mascarene islands, but little is known about the reproductive biology of its members. In this study, we quantified gender variation and flower-size variation in three populations of the dioecious tree Dombeya ciliata, an endemic of La Reunion Island...

Background and objectives: Bacterial blight of onion (BBO), a biennial plant species, is an emerging disease now present in many onion-producing areas. The causal agent, Xanthomonas axonopodis pv. allii (Xaa), is seedborne (2). Although the importance of seedborne Xaa as an initial inoculum source associated with the early stages of epidemics has b...

The genus Psiadia Jacq. represents the most important indigenous genus, by the number of species present, in the Mascarene archipelago (Mauritius, Reunion, Rodrigues), and is a typical example of adaptive radiation in oceanic islands. The Mauritius species are used in traditional pharmacopoeia for their expectorant properties, and most of them are...

Although many diclinous plants have a flower size dimorphism, the causes and ecological correlates of dimorphism in flower size remain poorly understood. In this paper we quantify the frequency and distribution of flower size dimorphism in the native flora of La Runion Island. The frequency of flower size dimorphism is lower than in a previous glob...

In the general context of conservation of insular habitats, the floral biology, natural fecundity, and breeding system of Geniostoma borbonica (Lam.) Spreng. was studied in natural populations. The species, which was initially assumed to be gynodioecious, presents two kinds of individuals, both with morphological hermaphroditic but functionally uni...

In this paper we examine whether variation in male and female flower size follows an allometric relation for 10 dioecious species in the genus Dombeya endemic to La Réunion. Male flowers are significantly larger than female flowers and the degree of dimorphism varies significantly across species. There is a significant allometric relationship betwe...

The high frequency of dioecy on oceanic islands such as Hawaii and New Zealand has attracted a great deal of attention from plant evolutionary biologists. One reason suggested for the high prevalence of dioecy on oceanic islands is that taxa considered truly dioecious may have occasional hermaphrodite flowers, i.e., show leaky dioecy. In this study...

The high frequency of dioecy on oceanic islands has attracted a great deal of attention in plant evolution. In this study we quantify variation in the breeding system of two sympatricDombeya species on La Runion island. BothDombeya species are cryptically dioecious, each sex retaining non-functional morphological structures of the other sex. One sp...

Les forts taux d'espèces dioïques sur les îles ont longtemps fasciné les biologistes. Or le fonctionnement de la dioécie en milieu insulaire a été peu abordé. Les variations dans l'expression de la dioécie et du dimorphisme sexuel de la taille des fleurs sont aujourd'hui examinés dans l'archipel des Mascareignes. A la réunion, les espèces unisexuée...

Surveys of oceanic island floras have shown that heterostyly is usually absent in such regions, probably because this floral polymorphism is often associated with a self-incompatibility system. In this context we describe the floral biology of three species ofErythroxylum on La Runion island and examine the compatibility relationships of one of the...

A micropropagation protocol for Psiadia arguta, an endangered endemic plant from Mauritius is described using 15-day old in vitro seedling explants without the radicle. MS basal medium supplemented with TDZ (0.5–1 mg/l) proved to be the most effective medium for the induction of cotyledonary axillary buds as compared to MS medium containing NAA (0....

The floral morphology, pollen grain viability and fecundity of 29 individuals of Bertiera borbonica A. Rich.ex DC var. borbonica in a natural population have been studied. Two kinds of individuals, both with morphologically hermaphroditic flowers occur. Individuals that produce fruits in natural conditions have flowers with bifid stigmas and anther...

The floral morphology, pollen grain viability and fecundity of 29 individuals of Bertiera borbonica A. Rich.ex DC var, borbonica in a natural population have been studied. Two kinds of individuals, both with morphologically hermaphroditic flowers occur. Individuals that produce fruits in natural conditions have flowers with bifid stigmas and anther...