Kiehr M, R Delhey

Phyton-International Journal of Experimental Botany, Vol.76, pp. 85-94, 2007, DOI:10.32604/phyton.2007.76.085

Abstract Wheat (Triticum aestivum) plants showing leaf spots associated with pycnidia of Stagonospora sp. were collected near the city of Tres Arroyos (Province of Buenos Aires, Argentina). The fungus was isolated in artificial media where it formed asexual and sexual fructifications which permitted its identification as Phaeosphaeria avenaria f. sp. triticea (anamorph S. avenae f. sp. triticea). The fungus was experimentally transmitted to wheat and barley plants and re-isolated, fulfilling Koch´s Postulates. This is the first record of P. avenaria f. sp. triticea in Argentina. More >

Grijalba PE, HE Palmucci

Phyton-International Journal of Experimental Botany, Vol.76, pp. 79-84, 2007, DOI:10.32604/phyton.2007.76.079

Abstract A new disease of Spathiphyllum wallisii plants, characterized by leaf yellowing and wilting due to root and crown rot, was observed in nurseries of the Great Buenos Aires, Argentina. A fungus was consistently isolated from diseased tissue and identified as Cylindrocladium spathiphylli, on the base of its morphological and cultural characteristics. Inoculation tests were carried out which confirmed this fungus as the causal agent of the disease. This is the first report of C. spathiphylli causing root and crown rot of S. wallisii in Buenos Aires. More >

Luján-Rangel¹ R, E Olivares-Sáenz², RE Vázquez-Alvarado², L Garza-Ocañas³, O Torres-Alanís³

Phyton-International Journal of Experimental Botany, Vol.76, pp. 61-77, 2007, DOI:10.32604/phyton.2007.76.061

Abstract Karwinskia parvifolia (Kp) and Karwinskia humboldtiana (Kh) are poisonous plants of the rhamnacea family. Toxicological and clinical studies performed with one of the compounds present in the fruit [peroxisomicine A1 (PA1)] suggest its possible pharmacological usefulness in the treatment of certain types of cancer. This is why these plants are cultivated: to increase their productivity of PA1. We studied the effects of nitrogen and species on seed viability. The germination curve was determined for Kp with (Kp-WN) and without (Kp-NN) nitrogen, and for Kh without nitrogen (Kh-NN) using the probit model. This is characterized by the probability of… More >

Bonvissuto¹ GL, CA Busso²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 47-59, 2007, DOI:10.32604/phyton.2007.76.047

Abstract Seed rain has ecological consequences on plant community structure. This study was conducted in the Monte Austral Neuquino nearby the town of Picún Leufú, Province of Neuquén, Argentina, within an area of 15 km x 15 km (39º 20 32' S; 69º19 30' W). Studies were conducted at two sites, distant 1.5 km from one another. Vegetation is distributed on the soil surface as vegetation patches. Four superficial locations may be found in the soil of these patches: location 1, small dune accumulated under the lee; location 2, found at the edge of the small… More >

Pérez-Amador¹ MC, V Muñoz Ocotero¹, JM García Castañeda¹, AR González Esquinca²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 39-45, 2007, DOI:10.32604/phyton.2007.76.039

Abstract A comparison was made between plants of Solanum torvum Sw that grow in Chiapas, Mexico, and plants of the same species originating from India. This was effected to establish either similarities or differences between these plants in total alkaloid contents and presence of solasodine, an important alkaloid for the partial synthesis of steroids. The total alkaloid content (0.12%) of the plants coming from Chiapas and India was the same. However, solasodine was found only in the plants of Chiapas. In addition, the total amount of glycoalkaloids (0.038%) and two glycosilated compounds derived from solasodine, solasonine (0.0043%) More >

Serrano-Bernardo F¹, JL Rosúa¹, M Díaz-Miguel²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 27-38, 2007, DOI:10.32604/phyton.2007.76.027

Abstract The Mediterranean region is considered one of the most important zones worldwide in terms of plant diversity. Sierra Nevada (S Spain) is a unique mountain massif within the high-mountain systems of the Mediterranean. It is of great floristic importance and very rich in endemic species. However, it requires numerous tasks for restoring plant cover due to the constant anthropic degradation, especially because of the ski station located near the second-highest peak of the mountain. One of the restoration efforts consists of trying to reproduce, in the laboratory, the ideal conditions to pre-germinate seeds of some… More >

García-Suárez¹ F, L Carreto-Montoya², R Cárdenas-Navarro³, JC Díaz-Pérez⁴, R López-Gómez

Phyton-International Journal of Experimental Botany, Vol.76, pp. 19-26, 2007, DOI:10.32604/phyton.2007.76.019

Abstract In this work we contribute to the knowledge of the reproductive phenology of Stenocereus stellatus (Pfeiffer,Riccobono), a columnar cactus that produces fruits of high commercial perspectives known as “pitayas”. This kind of pitayas are produced for local commercialization in back orchards in some regions of the Mexican dry tropics. These fruits are produced only in the apical part of the cactus “arms”. Our results show that fruit development of pitayas is highly associated to the rainy season of the year. This behavior is different from the reproductive strategy of other columnar cactus species that produce other More >

Rodríguez Rivera M F, LR Sosa, EA Fernández, M I Reale, V Villarreal

Phyton-International Journal of Experimental Botany, Vol.76, pp. 5-17, 2007, DOI:10.32604/phyton.2007.76.005

Abstract We studied the germination capacity of Bulnesia retama seeds to conditions of water stress simulated by PEG6000 at different temperatures. We also evaluated their recovery to water stress conditions. Seeds were collected in San Luis city, Argentina. They were placed in polyethylene bags with different concentrations of PEG6000 to simulate water potentials of 0 (control); -0.25; -0.5; -0.75; -1; -1.25 and -1.5 MPa. Seeds were placed in culture oven without light to three temperatures: 18º, 25º and 32 ºC. Non-germinated seeds were washed and placed again to germinate in distilled water to 25 ºC. We registered… More >

B.C. Heng*, K.J. Vinoth*, K. Lu*, X. Deng*, Z. Ge*, B.H. Bay**, T. Cao*

BIOCELL, Vol.31, No.3, pp. 405-410, 2007, DOI:10.32604/biocell.2007.31.405

Abstract We investigated the effects of prolonged heat shock treatment on human embryonic stem cell (hESC) viability. The hESC viability steadily declined with longer exposure to heat shock treatment (43ºC). After 4 h of exposure to heat shock at 43ºC, only 56.2 ± 1.5% of cells were viable. Viability subsequently declined to 37.0 ± 3.3% and 3.5 ± 0.7% after 8 h and 16 h, respectively of heat shock treatment at 43ºC. Transmission electron micrographs showed that the morphology of the dead/dying cells after heat shock treatment was characteristic of cellular necrosis with an uncondensed chromatin… More >

R. Canabarro^1,2, H. Sporleder², T. Gomes^3,4, G. Zanatta^3,5, L. Scribel^3,6, F. Freitas⁷, J. Neumann², P. Pranke^1,3

BIOCELL, Vol.31, No.3, pp. 397-403, 2007, DOI:10.32604/biocell.2007.31.397

Abstract The use of umbilical cord blood stem cells is an efficient alternative for the transplantation of hematopoietic progenitor cells. A number of factors can influence the volume and amount of CD34⁺ cells, which are considered as immature and capable of proliferation. Quantification of CD34⁺ cells, evaluation of CD38 and c-kit molecules on these cells, as well as correlations of such factors as maternal age, gestational age, newborn sex and weight, umbilical cord length, placental weight with increased volume and concentration of immature cells, among others, were performed in 70 blood samples from term newborns. The mean… More >