ABSTRACT
Abstract Acrostichum is a pantropical genus and has four species, two of which occur in the Neotropics, A. aureum and A. danaeifolium. In Mexico, A. danaeifolium grows further in land wet soils and is much more common than A. aureum, which is typically found in brackish or saline habitats near the coast, and is restricted to coastal saline mangrove communities. The purpose of this paper was to describe and compare the morphogenesis of the sexual phase of A. aureum and A. danaeifolium for systematic purposes. For this, spores of each species were sown in Petri dishes with agar, previously enriched with sterilized Thompson's medium. To avoid contamination and dehydration, the dishes were kept in transparent plastic bags under laboratory conditions. For the micro-morphological observation with SEM, the gametophyte development phases were fixed in FAA with 0.8 % sucrose for 24 h. Photomicrographs of spores, development stages of gametophytes and young sporophytes were observed with scanning electron microscope. Our results showed that the spores of both species are triletes, globose and positive photoblastic. Germination is Vittaria-type; the germinate filaments are short and uniseriate (5 to 7 cells), and prothallial development is Ceratopteris-type. The adult gametophytes of both species have asymmetrical wings. Adult gametophytes in culture are cordiform-spatulate. Antheridia have a broad basal cell, an annular cell, and an asymmetric opercular cell. Archegonia have short necks and four triangular cells at the mouth of the neck. The first leaf of the sporophyte is lobed, with dichotomous veins and anomocytic stomata. The gemmae are formed in adult gametophytes in both species. The development of the gametophyte of A. aureum, A. danaeifolium and A. speciosum share many similarities such as the development of a lateral meristem, asymmetric nature of the mature prothallus, lack of hairs on the prothallus, and undivided asymmetrical opercular antheridia morphology. The genus Acrostichum is the sister group of Ceratopteris, another genus of aquatic ferns; they differ in the antheridium morphology, Acrostichum has an asymmetric opercular cell and Ceratopteris shows an undivided cap cell, but the notable difference is the sporophyte morphology. Rev. Biol. Trop. 66(1): 178-188. Epub 2018 March 01.
Resumen Acrostichum es pantropical y tiene cuatro especies dos de las cuáles ocurren en el Neotrópico, A. aureum y A. danaeifolium. El género se encuentra típicamente en hábitats salobres o salinos cerca de la costa. También puede crecer más lejos en tierra en suelos húmedos. Acrostichum aureum está restringido a las comunidades de manglares salinos costeros. A. danaeifolium es mucho más común que A. aureum en México. El propósito de este trabajo es describir y comparar la morfogénesis de la fase sexual de A. aureum y A. danaeifolium. Las esporas de cada especie fueron sembradas en cajas de Petri, en agar previamente enriquecido con medio de Thompson esterilizado. Para evitar la contaminación y la deshidratación, las cajas se mantuvieron dentro de bolsas de plástico transparentes en condiciones de laboratorio. Para la observación micro-morfológica con el MEB, las fases de desarrollo del gametofito se fijaron en FAA con sacarosa al 0.8 % durante 24 h. Se observaron las esporas, fases de desarrollo de gametofitos y esporofitos jóvenes con un microscopio electrónico de barrido. Las esporas de ambas especies son triletes, globosas y fotoblásticas positivas. La germinación es tipo-Vittaria, los filamentos germinativos son cortos y uniseriados (5 a 7 células) y el desarrollo protálico es de tipo-Ceratopteris. Los gametofitos de ambas especies tienen alas asimétricas. Los gametofitos adultos en cultivo son cordiforme-espatulados. Los anteridios tienen una célula basal amplia, una célula anular y una célula opercular asimétrica. Los arquegonios tienen cuellos cortos y cuatro células triangulares en la boca del cuello. La primera hoja del esporofito es lobulada, con venación dicotómica y estomas anomocíticos. Las yemas se forman en gametofitos adultos en ambas especies. El desarrollo del gametofito de A. aureum, A. danaeifolium y A. speciosum comparten características tales como el desarrollo de un meristemo lateral, el protalo maduro de naturaleza asimétrica, ausencia de pelos en el protalo y anteridio con célula opercular asimétrica no dividida. Acrostichum es el grupo hermano de Ceratopteris, otro género de helecho acuático, que difieren en la morfología del anteridio, Acrostichum tiene una célula opercular asimétrica y Ceratopteris muestran una célula opercular no dividida.
ABSTRACT
Se evaluó la capacidad antagónica de nueve aislados del hongo Trichoderma sp. proveniente de la colección de cepas del Laboratorio de Fitopatología de la Universidad de Córdoba, Colombia y su producción de esporas en medios de cultivo líquido estático, a través de pruebas in vitro de antagonismo, utilizando dos hongos fitopatógenos: Fusarium sp. y Rhizoctonia sp.; esta prueba permitió seleccionar el aislado con la mayor actividad antagónica, para así ajustar la producción de esporas mediante un proceso de fermentación en estado líquido en condición estática mediante procesos de buferización y sin buferización con fosfato 0,2N, utilizándose como sustrato principal harina de plátano (HP) 5%, además de complementos nutricionales que constituyeron los tratamientos: HPM (solución de melaza 5%), HPL (solución de levadura granulada al 2%), HPU (solución de urea 0,1%), y como testigo PGL (papa glucosa líquida). En los ensayos de antagonismo se seleccionó el aislado C2 de Trichoderma sp. por presentar la mayor capacidad antagónica frente al hongo Fusarium sp., con un porcentaje de inhibición del 78,30% y reportando un índice 4 de antagonismo, en los procesos de producción de esporas el tratamiento HPL (harina de plátano más levadura sin buffer) se destacó por su favorable producción de conidias, con una concentración de 1,1 x 10(9) conidias/mL. Los procesos de buferización se diferenciaron significativamente, demostrando que la variable buffer influyó en la producción de conidias, los medios que se amortiguaron mostraron una producción de 1,01 x 10(9) conidias/mL, con respecto a los que no se amortiguaron 6,3 x 10(8) conidias/mL.
The antagonistisc ability of nine isolated natives fungi Trichoderma sp from the collection of strains at Laboratory of phytopathology at University of Cordoba, Colombia was assessed so as its production of spores in crop liquid static medium, cross the in vitro proof antagonism using two phytopathogenic fungi: Fusarium sp. and Rhizoctonia sp., this proof let select the isolated with the major antagonistic activity and adjust the production of spores through fermentation process in liquid static by means of buffer and without buffer with phosphate 0,2 N, being used as principal substrate plantain flour (HP) 5%, besides of nutritional supplements that formed the trataments: HPM (molasses solution 5%), HPL (granulated yeast solution at 2%), HPU (urea solution 0.1%), and as witness PGL (potato glucose liquid). In the test of antagonism was selected the isolated C2 of Trichoderma sp. by present the major antagonistic ability in front of the fungi Fusarium sp., with a inhibition percentage at 78,30% and reporting a index 4 of antagonism, in the process of spores production, the tratament HPL (plantain flour plus yeast without buffer) stressed for the favorable production of conidias, with a concentration of 1,1 x 10(9) conidias/mL. The buffer process were significant differentiated, showing that the variable buffer influenced in the production of conidias, the mediums that shocked in the production show 1,01 x 10(9) conidias/mL, Ïwith respect at dont shocked 6,3 x 10(8) conidias/mL.
ABSTRACT
The fern Blechnum sprucei grows in Mesoamerica (Costa Rica) and South America, from Colombia to Bolivia, SE and centre of Brazil, Paraguay and Argentina. It is a distinctive, somewhat vulnerable, mostly orophilous species. Fresh and dry herbarium material was used for this study. Herbarium material for anatomical studies comes from CTES, BA, LP, MA, SI and UC (Holmgren et al.1990). Selected representative specimens are additionally cited after taxonomic treatment of the species. Dry material was restored with aqueous 4:1 butil cellosolve. Pinnae were cleared with aqueous 6% NaOH, then coloured with aqueous 1 % TBO (Gurr 1966). Hand made transverse sections of young and adult stipes, and costae were done in fresh and restored herbarium material. Venation and epidermal patterns were analyzed in basal, apical and medium pinnae, but only the latter were illustrated. The size and density of stomata were measured in medium pinnae from all studied samples, values shown are the average of 25 measures per sample; sizes are expressed as minimum, media and maximum length x width, in µm, and density as minimum, media and maximum number of stomata / mm². Spores were studied with SEM, mounted on metal stubs with double sided tape, covered with gold under vacuum and photographed with a Jeol /EO JSM 6360 (15 KV) SEM. Spores were also studied with light microscope, mounted in DePex (DePex mounting medium, Gurr, BDH Laboratory Supplies, Poole BH15 1TD, UK) and measured using an ocular micrometer. Measurements are based on a minimum sample of 100 spores taken from different specimens. Sizes are expressed as the longest equatorial diameter/ polar diameter, in µm. Gametophytes were studied from material collected in the subtropical forest of Tucumán Province, Argentina. Spore samples for cultures were taken from single sporophytes kept dry at room temperature since the date plants were collected. Gametophytes were grown under fluorescent light. Multispore cultures were established on mineral agar. Percentage of germination was recorded for a random sample of 50 spores from each of the two plates, every three days until there was no further increasing. Gametophytes were stained with chloral hydrate acetocarmine. The species has large sporophytes, suberect, scaly rhizomes, and dimorphic fronds with short, scaly stipes and lanceolate to elliptic sterile laminae. The rachises can grow indefinitely as radicant axis that vegetatively multi-plicate the plants. Pinnae are lanceolate, herbaceous, with crenate and papillose margins, superficially scaly and hairy, peciolulate, with free, visible veins regularly once furcated near the costa, ending in large, active hydathodes. The broadly elliptic fertile laminae bear distant pinnae, with vegetative tissue reduced to the portion that supports the indusium and the continuous coenosorus; terminal indefinite rachis, not proliferous, may be present. Rev. Biol. Trop. 56 (4): 2027-2040. Epub 2008 December 12.
El helecho Blechnum sprucei crece en Mesoamérica (Costa Rica) y Sudamérica, desde Colombia a Bolivia, SE y centro de Brasil, Paraguay y Argentina. Es una especie característica, algo vulnerable y orófila. Se estudiaron caracteres exomorfológicos de especimenes provenientes de distintos puntos de su gran área de distribución. Adicionalmente, se llevó a cabo un detallado análisis de los modelos epidérmicos jóvenes y maduros, del indumento de la lámina y los ejes, y de la organización vascular en los estipes y costas. Se han estudiado por primera vez la morfología esporal, el desarrollo de los gametófitos, que resultaron cordados y pelosos, y su expresión sexual. Presenta esporófitos grandes, suberectos, con rizomas escamosos y frondas dimórficas, con estipes cortos y escamosos y láminas estériles de lanceoladas a elípticas. El raquis puede crecer indefinidamente como un eje radicante que multiplica las plantas vegetativamente. Las pinnas son lanceoladas, herbáceas, con márgenes crenados y papilosos, y la superficie escamosa y pelosa. Son pecioluladas, con venas libres y visibles, regularmente furcadas cerca de la costa, terminando en hidatodos grandes y activos. Las láminas fértiles son anchamente elípticas y portan pinnas distales; presentan tejido vegetativo reducido a la porción que soporta el indusio y el cenosoro continuo. Pueden presentar raquis indefinidos, pero no prolíferos.