Nematicidal Screening of Aqueous Extracts from Plants of the Yucatan Peninsula and Ecotoxicity.

Active metabolites from plants are considered safer than synthetic chemicals for the control of plant-parasitic nematodes of the genus Meloidogyne. In the present work, 75 aqueous extracts (AEs) from different vegetative parts of 34 native plant species of the Yucatan Peninsula were evaluated against second-stage juveniles (J2s) of Meloidogyne incognita and M. javanica in microdilution assays. The highest mortality (M) against both Meloidogyne species was produced by the foliar AE from Alseis yucatanensis (M ≥ 94%) and Helicteres baruensis (M ≥ 77%) at 3% w/v after 72 h. Other active AEs at 3% were from the leaves of Croton itzaeus and stems of H. baruensis (M: 87-90%) on M. javanica and the stems of Annona primigenia and the leaves of Morella cerifera on M. incognita (M: 92-97%). The AEs from A. yucatanensis had the lowest LD50 against M. incognita (0.36% w/v), and against M. javanica (3.80% w/v). In an acute ecotoxicity assay of the most promising AEs using non-target earthworms (Eisenia fetida), the AE of A. yucatanensis had slight acute toxicity (LD50: 2.80% w/v), and the rest of the most active AEs were not ecotoxic. These tropical plants are potential candidates for further studies as biorational agents for controlling Meloidogyne species.

Multilocus Data Analysis Reveal the Diversity of Cryptic Species in the Tillandsia ionantha (Bromeliaceae: Tillansiodeae) Complex.

Independent evolutionary lineages or species that lack phenotypic variation as an operative criterion for their delimitation are known as cryptic species. However, these have been delimited using other data sources and analysis. The aims of this study are: (1) to evaluate the divergence of the populations of the T. ionantha complex; and (2) to delimit the species using multilocus data, phylogenetic analysis and the coalescent model. Phylogenetic analyses, genetic diversity and population structure, and isolation by distance analysis were performed. A multispecies coalescent analysis to delimit the species was conducted. Phylogenetic analysis showed that T. ionantha is polyphyletic composed of eight evolutionary lineages. Haplotype distribution and genetic differentiation analysis detected strong population structure and high values of genetic differentiation among populations. The positive correlation between genetic differences with geographic distance indicate that the populations are evolving under the model of isolation by distance. The coalescent multispecies analysis performed with starBEAST supports the recognition of eight lineages as different species. Only three out of the eight species have morphological characters good enough to recognize them as different species, while five of them are cryptic species. Tillandsia scaposa and T. vanhyningii are corroborated as independent lineages, and T. ionantha var. stricta changed status to the species level.

Extracts from Six Native Plants of the Yucatán Peninsula Hinder Mycelial Growth of Fusarium equiseti and F. oxysporum, Pathogens of Capsicum chinense.

Fusarium equiseti strain FCHE and Fusarium oxysporum strain FCHJ were isolated from the roots of wilting habanero pepper (Capsicum chinense Jacq.) seedlings with root rot. Toward developing a biorational control of these serious phytopathogenic strains, ethanolic (EE) and aqueous (AE) extracts of different vegetative parts of 40 tropical native plants of the Yucatán Peninsula were screened for antifungal activity. Extracts of six out of 40 assayed plants were effective, and the most inhibitory extracts were studied further. EEs from Mosannona depressa (bark from stems and roots), Parathesis cubana (roots), and Piper neesianum (leaves) inhibited mycelial growth of both strains. Each active EE was then partitioned between hexane and acetonitrile. The acetonitrile fraction from M. depressa stem bark (MDT-b) had the lowest minimum inhibitory concentration of 1000 µg/mL against both pathogens and moderate inhibitory concentration (IC50) of 462 against F. equiseti and 472 µg/mL against F. oxysporum. After 96 h treatment with EE from M. depressa stem bark, both strains had distorted hyphae and conidia and collapsed conidia in scanning electron micrographs. Liquid chromatography-ultraviolet-high resolution mass spectrometry analysis revealed that the major component of the fraction was α-asarone. Its antifungal effect was verified using a commercial standard, which had an IC50 of 236 µg/mL against F. equiseti and >500 µg/mL against F. oxysporum. Furthermore, the P. cubana hexane fraction and P. neesianum acetonitrile fraction had antifungal activity against both Fusarium pathogens. These compounds provide new options for biorational products to control phytopathogenic fungi.

Orchid Diversity of the Palizada-del Este Fluvial Deltaic Lagoon System, in the Area de Protectión de Flora y Fauna Laguna de Términos, Campeche, Mexico / Diversidad de orquídeas del sistema fluvio lagunar deltaico palizada-del este, en el área de protección de flora y fauna laguna de términos, campeche, méxico

RESUMEN Se contribuye al conocimiento de la diversidad florística de la familia Orchidaceae presente en el sistema fluvio-lagunar-deltaico Palizada-del Este (SFLD-PE) a partir de los datos obtenidos de 15 recolectas realizadas en diez sitios, durante agosto 2013 a febrero 2014. El listado incluye 27 especies en 17 géneros. Ocho especies son nuevos registros para el SFLD-PE: Bletia purpurea, Catasetum integerrimum, Habenaria pringlei, H. repens, Laelia (Schomburgkia) rubescens, Myrmecophila tibicinis, Ornithocephalus inflexus y Rhetinantha friedrichsthalii. Los géneros con el mayor número de especies son Epidendrum (4) y Prosthechea (4). En lo que respecta al hábito de crecimiento, 23 especies son epífitas (85 %), tres especies son terrestres o semiacuáticas (12 %) y una especie es exclusivamente terrestre (3 %). Las especies mejor representadas en los sitios son Brassavola grandiflora (8), Bletia purpurea (7) y Habenaria repens (6). Los hospederos con mayor número de especies son Pachira aquatica (20) y Zygia latifolia (7). Epidendrum isthmi fue la única especie que se encuentra en alguna categoría de riesgo, de acuerdo a la NOM-059-SEMARNAT-2010. Diversas acciones antrópicas inciden negativamente en el SFLD-PE: deforestación, incendios y apertura de canales de agua provocan el deterioro y fragmentación de los hábitats, lo que pone en peligro el futuro de este grupo taxonómico y de otros grupos de plantas, por lo que el conocimiento de la biodiversidad de esta área es necesario para establecer estrategias de conservación, restauración y manejo sustentable.

ABSTRACT This paper is a contribution to the knowledge of the diversity of Orchidaceae in the Palizada del Este (SFLD-PE) fluvial-lagoon-deltic system based upon data generated from 15 collection events at ten sites conducted August 2012 through February 2014. The checklist includes 27 species in 17 genera. Eight species are new records for the SFLD-PE: Bletia purpurea, Catasetum integerrimum, Habenaria pringlei, H. repens, Laelia (Schomburgkia) rubescens, Myrmecophila tibicinis, Ornithocephalus inflexus, and Rhetinantha friedrichsthalii. The genera with the largest number of species are Epidendrum (4) and Prosthechea (4). As regards to life form, 23 species are epiphytic (85 %), three species are terrestrial or semiaquatic (12 %), and one species is terrestrial (3 %). The species present in more sites are Brassavola grandiflora (8), Bletia purpurea (7), and Habenaria repens (6). The hosts with the largest number of species are Pachira aquatica (20) and Zygia latifolia (7). Epidendrum isthmi is found in a risk category according to NOM-059-SEMARNAT-2010. Several anthropic actions negatively affect the SFLD-PE: deforestation, fires, and open water channels lead to deterioration and fragmentation of habitats, which threatens the future of this taxonomic group as well as that of other groups of plants. Thus, knowledge of the biodiversity of this area is necessary for developing sound strategies for conservation, restoration, and sustainable management.

Encyclia inopinata (Orchidaceae, Laeliinae) a new species from Mexico.

A new species of Encyclia from Mexico, Encyclia inopinata, is described and illustrated. This species is similar to Encyclia diota but it can be distinguished by its usually more robust plants with 2-3 leaves per pseudobulb and its flowers with longer and narrower sepals (1.8±0.1 × 0.63±0.03 cm in Encyclia inopinata versus 1.48 ±0.14 × 0.65±0.06 cm in Encyclia diota) and petals (1.7±0.05 × 0.59±0.05 cm in Encyclia inopinata vs. 1.36 ±0.19 × 0.81±0.13 cm in Encyclia diota), and the labellum with narrower lateral lobes (0.18±0.02 cm in Encyclia inopinata vs. 0.41±0.10 cm in Encyclia diota). Other characters that differentiate these two species are the coriaceous sepals, pink callus, and white anther of Encyclia inopinata (versus fleshy-leathery sepals, white callus, and yellow anther of Encyclia diota). The new species can be found in deciduous forests along the Pacific slope of Oaxaca state, near of the border with Guerrero state, at about 1200 m. It blooms between March and July.

ResumenUna nueva especie de Encyclia de México, Encyclia inopinata, es descrita e ilustrada. Esta especie es similar a Encyclia diota, pero puede distinguirse por sus plantas usualmente más robustas con 2­3 hojas por pseudobulbo y sus flores con sépalos y pétalos más largos y angostos (sépalos: 1.8±0.1 × 0.63±0.03 cm en Encyclia inopinata versus 1.48 ±0.14 × 0.65±0.06 cm en Encyclia diota; pétalos: 1.7±0.05 cm de largo en Encyclia inopinata vs 1.36 ±0.19 cm en Encyclia diota), el labelo tiene lóbulos laterales más angostos (0.18±0.02 cm en Encyclia inopinata vs. 0.41±0.10 cm en Encyclia diota). Otros caracteres que distinguen a las dos especies son los sépalos coriáceos, callo rosa y antera blanca de Encyclia inopinata (versus los sépalos carnoso-coriáceos, callo blanco y antera amarilla de Encyclia diota). La nueva especie se encuentra en un bosque deciduo del estado de Oaxaca, en la Vertiente del Pacífico, cerca de los límites con el estado de Guerrero, a 1200 m. Florece entre marzo y julio.

Anatomía foliar comparada y sistemática del clado-Trichocentrum con énfasis en Cohniella Asparagales: Orchidaceae / Comparative foliar anatomy and systematics of the Trichocentrum-clade with emphasis in Cohniella Asparagales: Orchidaceae

The genera Cohniella, Lophiarella, Lophiaris, and Trichocentrum are included in the Trichocentrum-clade. These genera are distributed from Florida and Northern Mexico to Southern Brazil and Northern Argentina, growing in tropical deciduous forests or tropical rain forests and thorn scrub forests to pine-oak forest, from sea level to 1 700m. The leaf anatomical structure of 23 members of the Trichocentrum-clade was explored as a source of taxonomic and phylogenetic characters. A total of 11 species of Cohniella, three species of Lophiarella, seven species of Lophiaris, two species of Trichocentrum, and other four species were included as outgroup. Anatomical characters were studied by cross sections and paradermic observations of the middle portion of fresh leaves. Although anatomical characters were fairly homogeneous throughout the clade, twelve vegetative anatomical, phylogenetically informative characters were selected and coded for an analysis that was performed using an exhaustive search implicit enumeration implemented through TNT. The strict consensus of 2 692 most parsimonious trees resulted in a poorly resolved polytomy, which however recovers the Trichocentrum-clade with a monophyletic, strongly supported Cohniella nested within it with unifacial leaves and the presence of cellular inclusions in the epidermis as synapomorphies. We concluded that the anatomy characters alone are insufficient to assess the relationships amongst the genera of the Trichocentrum-clade. However, the two synapomorphies recovered for Cohniella strongly support its monophyly when these are analyzed in conjunction with other data sources e.g., molecular and morphological characters.

El clado-Trichocentrum incluye los géneros Cohniella, Lophiarella, Lophiaris y Trichocentrum s.s. Estos géneros se distribuyen desde Florida y el Norte de México hasta el Sur de Brasil y Norte de Argentina, creciendo desde bosques caducifolios, bosques húmedos tropicales hasta matorrales espinosos y bosques de pino-encino, desde el nivel del mar hasta los 1 700m. En este estudio se exploró el valor taxonómico y filogenético de la estructura anatómica de las hojas de 23 especies del clado-Trichocentrum, repartidos en 11 especies de Cohniella, tres de Lophiarella, siete de Lophiaris y dos de Trichocentrum s.s., y de otras cuatro especies incluidas como grupo externo. Se realizaron secciones transversales y observaciones paradérmicas de la porción media de hojas frescas para el estudio de los caracteres anatómicos. Doce caracteres anatómico foliares fueron seleccionados y codificados para el análisis filogenético que se realizó mediante el uso de una búsqueda exhaustiva enumeración implícita con el programa TNT. El consenso estricto de 2 692 árboles más parsimoniosos dio lugar a una politomía que recupera dentro del clado-Trichocentrum a Cohniella como un clado monofilético fuertemente apoyado con sinapomorfías de las hojas unifaciales y la presencia de inclusiones celulares en la epidermis.

It takes two to tango: self incompatibility in the bromeliad Tillandsia streptophylla (Bromeliaceae) in Mexico.

Floral phenology and breeding system of Tillandsia streptophylla (Bromeliaceae) were studied in a low inundated forest in Yucatan, Mexico. During the flowering season, from March to August, terminal scapose 1-branched, paniculate inflorescences are produced with one flower per branch opening per day, over a period of 11-29 days. Flowers are tubular, light violet, with the stigma placed below the anthers, both protruding above the corolla. Flowers are protandrous, with anthers releasing pollen from 0500 hours and stigma becoming receptive around 0900 hours. Controlled experimental crosses suggest that Tillandsia streptophylla is self incompatible and therefore, pollinator-dependent.

Molecular characterization and phylogenetic relationships of Desmodium leaf distortion virus (DeLDV): a new begomovirus infecting Desmodium glabrum in Yucatan, Mexico.

The complete DNA-A component sequence of Desmodium leaf distortion virus (DeLDV, Begomovirus) isolated in Yucatan was determined to be 2569 nucleotides (nt) in length, and it was most closely related to Cotton leaf crumple virus-California (CLCrV-[Cal]), at 76%. The complete DNA-B component sequence was 2514 nt in length, and shared its highest nucleotide identity (60%) with Potato yellow mosaic Trinidad virus (PYMTV). Phylogenetic analyses group the DeLDV DNA-A component in the SLCV clade, whereas, the DeLDV DNA-B was grouped with the Abutilon mosaic virus clade, which also contains PYMV, suggesting that the DeLDV components have distinct evolutionary histories, possibly as the result of recombination and reassortment.

It takes two to tango: self incompatibility in the bromeliad Tillandsia streptophylla (Bromeliaceae) in Mexico

Floral phenology and breeding system of Tillandsia streptophylla (Bromeliaceae) were studied in a low inundated forest in Yucatan, Mexico. During the flowering season, from March to August, terminal scapose 1-branched, paniculate inflorescences are produced with one flower per branch opening per day, over a period of 11-29 days. Flowers are tubular, light violet, with the stigma placed below the anthers, both protruding above the corolla. Flowers are protandrous, with anthers releasing pollen from 0500 hours and stigma becoming receptive around 0900 hours. Controlled experimental crosses suggest that Tillandsia streptophylla is self incompatible and therefore, pollinator-dependent. Rev. Biol. Trop. 57 (3): 761-770. Epub 2009 September 30.

Estudiamos la fenología floral y el sistema de cruzamiento de la bromelia Tillandsia streptophylla (Bromeliaceae) en una selva baja inundable en Yucatán, México. Durante la estación de floración (marzo a agosto), las plantas producen una inflorescencia terminal, escaposa, paniculada, 1-dividida, con una flor abriendo por rama por día para un período de floración de 11-29 días por inflorescencia. Las flores son tubulares, de corola violeta claro, con el estigma y anteras exertos, pero las anteras más largas que el estigma en antesis. Las flores son protandras, con las anteras liberando el polen desde las 0500 horas y la receptividad del estigma comenzando a las 0900 horas. Los cruces experimentales controlados sugieren que Tillansdia streptophylla es auto incompatible y por ende, dependiente de los polinizadores.

Preliminary identification and coat protein gene phylogenetic relationships of begomoviruses associated with native flora and cultivated plants from the Yucatan Peninsula of Mexico.

A number of native and cultivated eudicots in the Yucatan Peninsula of Mexico (YPM) exhibit symptoms associated with virus infection. Symptomatic leaves were collected and assessed for begomoviral detection using polymerase chain reaction (PCR), and universal primers that amplify a fragment of the coat protein gene (core Cp). Begomovirus were detected in nine native and seven cultivated species, representing seven eudicot families. DNA extracts from the 16 hosts were used for PCR amplification and sequencing of a fragment containing the coat protein (Cp) gene. The complete Cp sequence was used to establish provisional species identification. Results indicated that 13 distinct begomovirus species were represented. Among these, five potentially new begomovirus species were identified, for which we propose the names Anoda golden mosaic virus (AnGMV), Boerhavia yellow spot virus (BoYSV), Papaya golden mosaic virus (PaGMV), Desmodium leaf distortion virus (DeLDV), and Hibiscus variegation virus (HiVV). Five previously described begomoviral species were provisionally identified for the first time in the YPM; these include Euphorbia mosaic virus (EuMV), Melon chlorotic leaf curl virus (MCLCuV), Okra yellow mosaic Mexico virus (OkYMMV), Sida golden mosaic virus (SiGMV), and Tobacco apical stunt virus (TbASV). Additionally, viruses previously reported from this region, Bean golden yellow mosaic virus (BGYMV), Pepper golden mosaic virus (PepGMV), and Tomato mottle virus (ToMoV) were provisionally identified in cultivated hosts. Phylogenetic analysis provisionally placed all isolates from the YPM in a Western Hemisphere begomovirus clade.

Molecular characterization and phylogenetic relationships of two new bipartite begomovirus infecting malvaceous plants in Yucatan, Mexico.

Sida acuta and Corchorus siliquosus plants showing yellow mosaic and yellow vein symptoms, respectively, were collected in the Yucatan Peninsula, Mexico. Total DNA was isolated from both plant species and used for the amplification, cloning, and sequencing of the Begomovirus genome. Nucleotide comparison of the complete DNA-A component isolated from S. acuta and C. siliquosus confirmed the presence of two distinct begomoviruses species. Based on phenotypic symptoms observed in infected field plants, the names Sida yellow mosaic Yucatan virus (SiYMYuV) and Corchorus yellow vein Yucatan virus (CoYVYuV) were proposed. The SiYMYuV DNA-A shared the highest nucleotide identity (86%) with the Okra yellow mosaic Mexico virus (OkYMMV). The complete DNA-B component shared the highest nucleotide identity (80%) with CoYVYuV. The CoYVYuV DNA-A shared the highest nucleotide identity (84%) with SiYMYuV. The 166-nt common region (CR) sequence for the DNA-A and DNA-B components of SiYMYuV shared a high nucleotide identity of 99%, and the 151 nt of CoYVYuV CR shared 95% of nucleotide identity. The organization and the iterated sequence of the putative AC1 binding site (located within the common region) of both isolates, were similar to that of the begomoviruses of the Western Hemisphere. Phylogenetic analyses placed the DNA-A and DNA-B of SiYMYuV and CoYVYuV in the clade containing the Abutilon mosaic virus (AbMV).

Molecular phylogenetics of Maxillaria and related genera (Orchidaceae: Cymbidieae) based on combined molecular data sets.

The orchid genus Maxillaria is one of the largest and most common of neotropical orchid genera, but its current generic boundaries and relationships have long been regarded as artificial. Phylogenetic relationships within subtribe Maxillariinae sensu Dressler (1993) with emphasis on Maxillaria s.l. were inferred using parsimony analyses of individual and combined DNA sequence data. We analyzed a combined matrix of nrITS DNA, the plastid matK gene and flanking trnK intron, and the plastid atpB-rbcL intergenic spacer for 619 individuals representing ca. 354 species. The plastid rpoC1 gene (ca. 2600 bp) was sequenced for 84 selected species and combined in a more limited analysis with the other data sets to provide greater resolution. In a well-resolved, supported consensus, most clades were present in more than one individual analysis. All the currently recognized minor genera of "core" Maxillariinae (Anthosiphon, Chrysocycnis, Cryptocentrum, Cyrtidiorchis, Mormolyca, Pityphyllum, and Trigonidium) are embedded within a polyphyletic Maxillaria s.l. Our results support the recognition of a more restricted Maxillaria, of some previously published segregate genera (Brasiliorchis, Camaridium, Christensonella, Heterotaxis, Ornithidium, Sauvetrea), and of several novel clades at the generic level. These revised monophyletic generic concepts should minimize further nomenclatural changes, encourage monographic studies, and facilitate more focused analyses of character evolution within Maxillariinae.