Cytological characterization in Flaveria bidentis and F. haumanii (Asteraceae)

Antecedentes y Objetivos: Flaveria es un género americano integrado por 23 especies y representado en Argentina por dos de ellas, ambas nativas y anuales: F. bidentis (la cual es considerada maleza de agroecosistemas) y F. haumanii. El género tiene un número cromosómico básico de x=18 y los antecedentes citológicos son referidos a F. bidentis, pero no así para F. haumanii. El objetivo de este trabajo fue caracterizar citogenéticamente a F. bidentis y F. haumanii a través del análisis cariotípico, el comportamiento meiótico y la estimación de la viabilidad de los granos de polen.Métodos: El material fue recolectado en la provincia de Santiago del Estero (Argentina). Las raíces fueron pretratadas con 8-hidroxiquinoleina 0.002 M durante ocho horas. Inflorescencias y raíces fueron fijadas en Farmer y conservadas en alcohol etílico al 70% en frío. Para la tinción de los cromosomas se utilizó hematoxilina propiónica al 2%. La viabilidad de los granos de polen se estimó mediante las soluciones colorantes de Mützing y DAF.Resultados clave: Flaveria bidentis y F. haumanii poseen como número cromosómico esporofítico 2n=36, con un cariotipo unimodal simétrico. El comportamiento meiótico es regular y en diacinesis se observó n=18 bivalentes; la viabilidad estimada de los granos de polen fue superior a 90%.Conclusiones: Se mencionan por primera vez los números cromosómicos esporofíticos y gametofíticos de F. haumanii; además, se completa la informacióncitogenética para F. bidentis a través del análisis de la meiosis. Estos son los primeros datos relacionados con la viabilidad de los granos de polen.Background and Aims: Flaveria is an American genus with 23 species; in Argentina it is represented by two of them both native and annual: F. bidentis (which is cited as a weed of agroecosystems) and F. haumanii. The genus is mentioned with a base chromosome number of x=18 and cytogenetic backgrounds for F. bidentis are know, but not so for F. haumanii. The aim of this work was to cytogenetically characterize F. bidentis and F. haumanii through the analysis of mitosis, meiotic behavior and estimation of pollen grain viability. Methods: The material was collected in the province of Santiago del Estero (Argentina). The root tips were pretreated with 8-hydroxyquinoline 0.002 M for eight hours. Inflorescences and root tips were fixed in Farmer and preserved in cold 70% ethyl alcohol. To stain chromosomes 2% propionic hematoxylin was used. The viability of pollen grains was estimated with the Mützing and DAF stain solutions. Key results: Flaveria bidentis and F. haumanii have a sporophytic chromosome number of 2n=36, with a symmetric unimodal karyotype. The meiotic behavior was regular, in diakinesis n=18 bivalent was observed and the estimated viability of the pollen grains was greater than 90%. Conclusions: The sporophytic and gametophytic chromosomal numbers of F. haumanii are mentioned for the first time; in addition, through meiotic analysis the cytogenetic information is completed for F. bidentis. These are the first data related to pollen grain viability

Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae)

Antecedentes y Objetivos: La gran variabilidad de caracteres en Dioscorea dificultan la delimitación de las especies, por lo que estudios complementarios son necesarios para lograr su identificación. Dioscorea ayardei, especie endémica descrita recientemente de las Sierras de Calilegua (Jujuy, Argentina), se diferencia por la particularidad del androceo en sus flores estaminadas, la cual consiste en una estructura navicular con una sola antera en el centro y tres apéndices dendriformes erectos. El objetivo de este trabajo fue realizar un estudio conjunto de sus caracteres cromosómicos y palinológicos, que sumados a los morfológicos aporten información complementaria para su correcta delimitación. Métodos: El material estudiado fue identificado según los métodos clásicos en taxonomía y depositado en el Herbario LIL, de la Fundación Miguel Lillo. Para estudiar la meiosis se seleccionaron al azar botones florales jóvenes, que fueron fijados en Farmer durante 24 horas y conservados en alcohol etílico 70° a -4°C. La tinción de los cromosomas se realizó con hematoxilina propiónica al 2%. La fertilidad de los granos de polen se estimó mediante las técnicas de Mützing y DAPI. Para describir la morfología polínica, el material fue procesado según las técnicas convencionales de acetólisis y polen natural; se tomaron fotos con microscopía óptica (MO) y electrónica de barrido (MEB). Resultados clave: Dioscorea ayardei presentó un número gametofítico n=20II. El comportamiento meiótico fue generalmente regular. Las técnicas para estimar viabilidad y fertilidad del grano de polen revelaron un valor de 90-93% respectivamente. La morfología muestra un grano disulcado de tamaño pequeño (16-24 µm) a mediano (25-30 µm) con tectum microreticulado. Conclusiones: Se reafirma el número cromosómico básico para el género x=10. Dioscorea ayardei es un tetraploide con n=20, de comportamiento meiótico normal que concuerda con la viabilidad potencial del grano de polen. La ornamentación de la exina y el número cromosómico la relaciona con el clado Nuevo Mundo II.Background and Aims: The great variability of characters in Dioscorea makes it difficult to define the species, therefore additional studies are necessary to identify them. Dioscorea ayardei, a recently described endemic species from the Sierras de Calilegua (Jujuy, Argentina), differs by the particularity of the androecium of its staminate flowers which consists of a navicular structure with a single anther in the center and three erect dendriform appendages. The aim of this paper was to carry out an ensemble study of its chromosomal and palynological characters that, added to the morphological ones, provide complementary information for its correct delimitation. Methods: The studied material was identified according to the classic methods in taxonomy and deposited in the LIL Herbarium, of the Fundación Miguel Lillo. For study of meiosis, young flower buds were randomly selected, which were fixed in Farmer for 24 hours and preserved in 70° to -4°C ethyl alcohol. For chromosome staining, 2% propionic hematoxylin was used. Fertility of pollen grains was estimated using the Mützing and DAPI techniques. For the pollen morphology description the material was processed according to the conventional techniques of acetolysis and natural pollen; photographs were taken with light microscope (LM) and scanning electron microscope (SEM). Key results: Dioscorea ayardei presented a gametophytic number n=20II. Meiotic behavior was generally regular. The techniques to estimate viability and fertility of the pollen grain revealed a value of 90-93%, respectively. The morphology showed a small (16-24 µm) to medium (25-30 µm) sized disulcate grain with microreticulate tectum. Conclusions: The basic chromosome number for the genus x=10 is reaffirmed. Dioscorea ayardei is a tetraploid with n=20, with normal meiotic behavior consistent with the potential viability of the pollen grain. The exine ornamentation and chromosome number relates with the New World II clade

Caracterización citológica en Flaveria bidentis y F. haumanii (Asteraceae)

Background and Aims: Flaveria is an American genus with 23 species; in Argentina it is represented by two of them both native and annual: F. bidentis (which is cited as a weed of agroecosystems) and F. haumanii. The genus is mentioned with a base chromosome number of x=18 and cytogenetic backgrounds for F. bidentis are know, but not so for F. haumanii. The aim of this work was to cytogenetically characterize F. bidentis and F. haumanii through the analysis of mitosis, meiotic behavior and estimation of pollen grain viability. Methods: The material was collected in the province of Santiago del Estero (Argentina). The root tips were pretreated with 8-hydroxyquinoline 0.002 M for eight hours. Inflorescences and root tips were fixed in Farmer and preserved in cold 70% ethyl alcohol. To stain chromosomes 2% propionic hematoxylin was used. The viability of pollen grains was estimated with the Mützing and DAF stain solutions. Key results: Flaveria bidentis and F. haumanii have a sporophytic chromosome number of 2n=36, with a symmetric unimodal karyotype. The meiotic behavior was regular, in diakinesis n=18 bivalent was observed and the estimated viability of the pollen grains was greater than 90%. Conclusions: The sporophytic and gametophytic chromosomal numbers of F. haumanii are mentioned for the first time; in addition, through meiotic analysis the cytogenetic information is completed for F. bidentis. These are the first data related to pollen grain viability.Resumen:Antecedentes y Objetivos: Flaveria es un género americano integrado por 23 especies y representado en Argentina por dos de ellas, ambas nativas y anuales: F. bidentis (la cual es considerada maleza de agroecosistemas) y F. haumanii. El género tiene un número cromosómico básico de x=18 y los antecedentes citológicos son referidos a F. bidentis, pero no así para F. haumanii. El objetivo de este trabajo fue caracterizar citogenéticamente a F. bidentis y F. haumanii a través del análisis cariotípico, el comportamiento meiótico y la estimación de la viabilidad de los granos de polen.Métodos: El material fue recolectado en la provincia de Santiago del Estero (Argentina). Las raíces fueron pretratadas con 8-hidroxiquinoleina 0.002 M durante ocho horas. Inflorescencias y raíces fueron fijadas en Farmer y conservadas en alcohol etílico al 70% en frío. Para la tinción de los cromosomas se utilizó hematoxilina propiónica al 2%. La viabilidad de los granos de polen se estimó mediante las soluciones colorantes de Mützing y DAF.Resultados clave: Flaveria bidentis y F. haumanii poseen como número cromosómico esporofítico 2n=36, con un cariotipo unimodal simétrico. El comportamiento meiótico es regular y en diacinesis se observó n=18 bivalentes; la viabilidad estimada de los granos de polen fue superior a 90%.Conclusiones: Se mencionan por primera vez los números cromosómicos esporofíticos y gametofíticos de F. haumanii; además, se completa la informacióncitogenética para F. bidentis a través del análisis de la meiosis. Estos son los primeros datos relacionados con la viabilidad de los granos de polen.Palabras clave: cariotipo, comportamiento meiótico, mitosis, viabilidad del polen

Quaternary and pentanar mesoporous bioactive glass nanoparticles as novel nanocarriers for gallic acid: Characterisation, drug release and antibacterial activity

Mesoporous bioactive glass nanoparticles (MBGNs) have gained considerable attention as multifunctional platforms for simultaneously releasing ions and phytotherapeutic compounds. Thus, in the first part of this study, MBGNs based on the 53SiO₂–4P₂O₅–20CaO–23Na₂O (wt %) (S53P4) composition were synthesized by a microemulsion assisted sol-gel method. More precisely, P₂O₅ was substituted with B₂O₃ and Na₂O with MgO and/or ZnO. For B containing MBGNs all ions were successfully incorporated into the borosilicate structure without inducing crystallisation. In contrast, for S53P4 a poorly crystalline hydroxyapatite phase was identified. All MBGNs had a typical spherical shape with an internal radial network of mesopores. Additionally, for S53P4 a second fraction of particles with a smaller size and compact core was observed. Secondly, the feasibility of MBGNs as nanocarriers for gallic acid (GA) was evaluated. All drug-loaded samples showed a similar in vitro release profile which can be divided into three main phases: burst release, slow release and sustained release. Among the different compositions, S53P4 exhibited the highest cumulative release, whereas B and Mg containing particles exhibited the opposite. The presence of Zn in the MBGN compositions improved their antibacterial effect against both E. coli and S. aureus. Moreover, it was shown that depending on the MBGNs’ composition, the antibacterial activity of GA loaded MBGNs can be enhanced. Thus, the results proved that MBGNs can be used as controlled drug delivery system and, by tailoring the composition, a synergistic antibacterial effect can be achieved, considering that GA and biologically active ions are simultaneously released.Universidad de Sevilla (CITUS

Ploidy level and obligate apogamy in two populations of Argyrochosma nivea var. tenera (Pteridaceae)

ABSTRACT Argyrochosma nivea var. tenera is a cheilanthoid fern from the American continent. We present herewith the study of meiotic behavior and gametic number as well as number of spores and reproduction mode (with observations from cultured gametophytes). The study material is from Northwestern Argentina. For the study of meiosis, sporangia were fixed in ethanol-acetic acid (3:1) and stained with 2% propionic haematoxylin. Micrographs were taken using light and scanning electron microscopes. Meiotic chromosome number is 2n = 3x = 81 and the presence of lagging chromosomes at telophase II is mentioned for the first time; three sets of chromosome occur at diakinesis. Sporangia have 32 trilete spores. Adult gametophytes are laminar, cordiform, asymetrical, glabrous, without glandular trichomes. In our samples, the adult gametophytes were neuter, without antheridia or archegonia, with obligate apogamous reproduction. Both populations studied might be of hybrid origin

Ploidy level and obligate apogamy in two populations of Argyrochosma nivea var. tenera(Pteridaceae)

ABSTRACTArgyrochosma nivea var. tenera is a cheilanthoid fern from the American continent. We present herewith the study of meiotic behavior and gametic number as well as number of spores and reproduction mode (with observations from cultured gametophytes). The study material is from Northwestern Argentina. For the study of meiosis, sporangia were fixed in ethanol-acetic acid (3:1) and stained with 2% propionic haematoxylin. Micrographs were taken using light and scanning electron microscopes. Meiotic chromosome number is 2n = 3x = 81 and the presence of lagging chromosomes at telophase II is mentioned for the first time; three sets of chromosome occur at diakinesis. Sporangia have 32 trilete spores. Adult gametophytes are laminar, cordiform, asymetrical, glabrous, without glandular trichomes. In our samples, the adult gametophytes were neuter, without antheridia or archegonia, with obligate apogamous reproduction. Both populations studied might be of hybrid origin

Chromosome numbers in insects of Argentina I. Cytogenetic characterization of 15 species with economic importance.

In the present study, the somatic and gametic chromosome numbers in fifteen species of insects from Argentina are reported. Said species are characterized for their economic importance as pest of crops or as agricultural pest controllers. The species belonged to the following orders and families: Neuroptera, Chrysopidae: Ceraeochrysa cincta (n = 5 + XY), Ceraeochrysa paraguaria (n = 5 + XY), Chrysoperla argentina (n = 5 + XY), Chrysoperla asoralis (n = 5 + XY), Chrysoperla externa (n = 5 + XY), Leucochrysa cruentata (n = 7 + XY) y Plesiochrysa elongate (n = 5 + XY), Coleoptera, Coccinellidae: Cyclonela sanguinea (n = 9 + XYp), Eriopis connexa (n = 9 + XYp), Harmonia axyridis (n = 7 + XYp), Hippodamia convergens (n = 9 + XYp), y Melyridae: Astylus atromaculatus (n = 8 + XYp), Dermaptera, Forficulidae: Doru lineare (2n = 20) and D. luteipes (2n = 20), Diptera, Ulidiidae: Euxesta eluta (n = 5 + XY). Chromosomal information for six species and additional gametic chromosome number for Euxesta eluta are established for the first time. In addition, a new chromosome number is cited for Astylus atromaculatus that is different to the one previously reported

Números cromosómicos en insectos de Argentina. I. Caracterización citogenética en 15 especies de importancia económica

In the present study, the somatic and gametic chromosome numbers in fifteen species of insects from Argentina are reported. Said species are characterized for their economic importance as pest of crops or as agricultural pest controllers. The species belonged to the following orders and families: Neuroptera, Chrysopidae: Ceraeochrysa cincta (n = 5 + XY), Ceraeochrysa paraguaria (n = 5 + XY), Chrysoperla argentina (n = 5 + XY), Chrysoperla asoralis (n = 5 + XY), Chrysoperla externa (n = 5 + XY), Leucochrysa cruentata (n = 7 + XY) y Plesiochrysa elongate (n = 5 + XY), Coleoptera, Coccinellidae: Cyclonela sanguinea (n = 9 + XYp), Eriopis connexa (n = 9 + XYp), Harmonia axyridis (n = 7 + XYp), Hippodamia convergens (n = 9 + XYp), y Melyridae: Astylus atromaculatus (n = 8 + XYp), Dermaptera, Forficulidae: Doru lineare (2n = 20) and D. luteipes (2n = 20), Diptera, Ulidiidae: Euxesta eluta (n = 5 + XY). Chromosomal information for six species and additional gametic chromosome number for Euxesta eluta are established for the first time. In addition, a new chromosome number is cited for Astylus atromaculatus that is different to the one previously reported.En el presente trabajo se informan los números cromosómicos somáticos y/o gaméticos de 15 especies de insectos presentes en Argentina, que se caracterizan por su importancia económica como plagas de cultivos o controladores de plagas agrícolas, pertenecientes a los siguientes órdenes y familias: Neuroptera, Chrysopidae: Ceraeochrysa cincta (n = 5 + XY), Ceraeochrysa paraguaria (n = 5 + XY), Chrysoperla argentina (n = 5 + XY), Chrysoperla asoralis (n = 5 + XY) , Chrysoperla externa (n = 5 + XY), Leucochrysa cruentata (n = 7 + XY) y Plesiochrysa elongata (n = 5 + XY), Coleoptera, Coccinellidae: Cycloneda sanguinea (n = 9 + XYp), Eriopis connexa (n = 9 + XYp), Harmonia axyridis (n = 7 + XYp), Hippodamia convergens (n = 9 + XYp) y Melyridae: Astylus atromaculatus (n = 8 + XYp), Dermaptera, Forficulidae: Doru lineare (2n = 20), D. luteipes (2n = 20) y Diptera, Ulidiidae: Euxesta eluta (n = 5 + XY). Por primera vez, se cita información cromosómica para seis especies, incluyendo un número cromosómico gamético adicional para Euxesta eluta. Además, se da a conocer en Astylus atromaculatus un número cromosómico diferente a los recuentos previamente reportados

Determinacion de cromosomas holocineticos a través de la secuencia CID (cenp) en Dermaptera y Neuroptera (Insecta)

During cell division, the centromere is an indispensable chromosomal region to ensure the segregation of geneticsinformation. In most eukaryotes, the identity of the centromere is determined by the presence of the CENP protein(CID in Diptera). Some groups of animals have chromosomes that lack localized centromeres (holocentric); a clearexample of this is Dermaptera, although the holocentricity of their chromosomes is questioned since structuressimilar to centromeres were observed in them. It is also believed that neuroptera carries chromosomes with localizedcentromeres (monocentric), but recent studies have questioned this assertion since Chrysoperla presentschromosomes lacking centromeres. The aim of this work was to determine the holocentricity of chromosomes ofDoru linerae, D. luteipes (Dermaptera) and Chrysoperla externa (Neuroptera) by amplifying the CENP gen. Usingthe Quiagen extraction kit, total DNA was obtained fromf Droshophila melanogaster, Zaprionus indianus gupta(Diptera) and Astylus atromaculatus (Coleoptera) species with monocentric chromosomes and the target species. Theprimers used were: Fw-5´GAGAACGGAGCTTGGGTT3´; Rv5´CGTCGGCGAACAACTCAAG3´. PCRamplification was performed with conventional protocols. The final product was identified in 1% agarose gel. ThePCR reaction was positive for Diptera and Coleoptera. The lack of amplicons of CENP gen in Doru and Chrysoperlais another fact that demonstrates the holocentricity of their chromosomes.Fil: Silenzi Usandivaras, Gabriela Maria. Fundación Miguel Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Álvarez, R. E.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Andrada, Aldo Rubén. Fundación Miguel Lillo; ArgentinaFil: Oviedo, Andrea Verónica de Fátima. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Moreno Ruiz Holgado, Maria Macarena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Ruiz de Bigliardo, Graciela. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Fundación Miguel Lillo; ArgentinaFil: Romero Sueldo, Gladys Mabel. Fundación Miguel Lillo; ArgentinaXXXV Annual Scientific Meeting of the Tucuman Biology AssociationSan Miguel de TucumánArgentinaAsociación de Biología de Tucumá