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American Journal of Plant Sciences 2012年第4期3卷 489-494页

作者： Marisol Jiménez Andrés Gatica Ethel Sánchez marta valdez Centro de Investigación en Estructuras Microscópicas (CIEMic) Universidad de Costa Rica San Pedro de Montes de Oca Costa Rica Laboratorio de Biotecnología y Transformación Genética de Plantas Escuela de Biología Universidad de Costa Rica San Pedro de Montes de Oca Costa Rica

Common bean (Phaseolus vulgaris L.) is an economic important crop and one of the major grain legumes for human consumption in Latin America, Africa and Asia. A morphological study of shoot induced from embryonic axes development in four Costa Rican bean varieties (Brunca, Huetar, Guaymi and Bribri) cultivated on MS media with or without 5 mg·L–1 de N6-benzylaminopurine (BAP) by scanning electron microscopy (SEM) was developed in the present work. Micrographs showed similarities and differences in the ultrastructure of the apical dome, epidermal surface, stomata and different types of trichomes in the varieties cultivated on organogenesis media. Genotypes with advantageous morphological characteristics for genetic transformation, in particular an exposed apical dome, were identified. This work will contribute to the optimization of the in vitro regeneration of four common bean varieties.

关键词： Phaseolus vulgaris L Bean In Vitro Organogenesis Shoot Scanning Electron Microscopy (SEM)

Genetic Diversity Analysis of Jatropha Species from Costa Rica Using AFLP Markers

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American Journal of Plant Sciences 2015年第14期6卷 2426-2438页

作者： Roberto Avendano Elmer García Díaz marta valdez-Melara Nefertiti Chaves Solano Aníbal Mora Villalobos Francisco Aguilar Cascante Bruce Williamson Benavides Laura Y.Solís-Ramos Center for Biotechnological Innovations(CENIBiot) CeNAT-CONARESan JoséCosta Rica School of Biology University of Costa RicaSan JoséCosta Rica

The genetic diversity from species of the genus Jatropha collected from Costa Rica was analyzed by AFLP (amplified fragments length polymorphism). The study consisted of 114 accessions from 15 populations of 4 different species: J. curcas, J. costaricensis, J. gossypifolia and J. stevensii. These were collected from different locations in Costa Rica. Three different primers were used, resulting in 428 loci, and they were classified in three categories: unique and double bands (UBD), rare bands (RB) and shared bands (SB). The UBD were excluded for a total of 339 polymorphic loci used for the UPGMA dendrogram and principal component analysis (PCA). The species that obtained the highest average of polymorphic loci was J. curcas, which obtained the highest percentage of polymorphic loci (80.24%), followed by J. gossypifolia (79.35%), J. costaricensis (78.76%), and finally J. stevensii (40.71%). The average for the polymorphic loci was of 69.76%. Thus, the phylogeny of the Jatropha species in Costa Rica was elucidated, showing J. curcas more related to J. stevensii and this one with J. costaricensis, and J. gossypifolia as the most distant member of the genus. For the best of our knowledge this is the first report of a genetic analysis of J. costaricensis and J. stevensii. The obtained molecular evidence showed high levels of polymorphisms in the present study compared with reports from Africa, India, and China. The molecular diversity estimated in our analysis, together with agronomical or morphological data, can be very useful for plant breeding programs, given the importance of Jatropha species in oil production. Interestingly, Central American Jatropha material can be used to increase the genetic base of J. curcas populations localized in Asia and Africa, where reduced genetic diversity has been reported.

关键词： Jatropha spp. AFLP Molecular Markers Polymorphism Genetic Diversity

Effect of Gamma Irradiation and Selection with Fungus Filtrate(Rhizoctonia solani Kuhn)on the in Vitro Culture of Common Bean(Phaseolus vulgaris)

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American Journal of Plant Sciences 2015年第16期6卷 2672-2685页

作者： Laura Y.Solís-Ramos marta valdez-Melara Ricardo Alvarado-Barrantes Floribeth Mora-Umana Eduardo Hernández-Jiménez Natalia Barboza-Vargas Pilar Ramírez-Fonseca Plant Biotechnology & Genetic Transformation School of Biology University of Costa Rica San Pedro Costa Rica School of Statistic University of Costa Rica San Pedro Costa Rica Interagency Cooperation Agreement between the Research Center for Cellular and Molecular Biology (CIBCM) University of Costa Rica and the Phytosanitary Agency of the Ministry of Agriculture and Livestock (MAG) San José Costa Rica Research Center for Cellular and Molecular Biology (CIBCM) University of Costa Rica San Pedro Costa Rica

The present investigation was undertaken to study the effect of gamma irradiation (dose from 10 to 100 Gy) and in vitro selection with fungus filtrate as selecting agent (concentration from 20% to 100%) on the susceptibility of the common bean to Rhizoctonia solani. The best results were found with a dose of 20 Gy or a concentration of 20% of fungus filtrate applied separately. These conditions were used to evaluate the combined effect of both approaches in a second experiment. The combined effect of irradiation and then selection adversely affected growth (height and roots) and survival of the in vitro plants. It may not be necessary to combine the variation generated by irradiation with the selection technique. For future assays we propose the application of: 1) gamma radiation, thereby inducing not only mutants with pathogen resistance, but also with other agronomic traits of interest. Later in the subculture MV4 potential fungus-resistant mutants will be evaluated in the field;or 2) selection pressure using fungus filtrate during three subcultures, which may be sufficient to induce the variation necessary to obtain in vitro plants resistant to fungus.

关键词： Mutagenesis Radiosensitivity In Vitro Selection Rhizoctonia Common Bean

Therapeutic effect of Streptococcus thermophilus CRL 1190-fermented milk on chronic gastritis

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World Journal of Gastroenterology 2010年第13期16卷 1622-1630页

作者： Cecilia Rodríguez marta Medici Fernanda Mozzi Graciela Font de valdez Centro de Referencia para Lactobacilos (CERELA)-CONICET Cátedra Microbiología Superior Facultad de Bioquímica Química y Farmacia Universidad Nacional de Tucumán

AIM: To investigate the potential therapeutic effect of exopolysaccharide (EPS)-producing Streptococcus thermophilus (S. thermophilus) CRL 1190 fermented milk on chronic gastritis in Balb/c mice. METHODS: Balb/c mice were fed with the fermented milk for 7 d after inducing gastritis with acetyl-salicylic acid (ASA, 400 mg/kg body weight per day for 10 d). Omeprazole was included in this study as a positive therapeutic control. The gastric in? ammatory activity was evaluated from gastric histology and in? ammation score, number of interleukin-10 (IL-10), interferon-γ (INFγ) and tumor necrosis factor-α (TNF-α) cytokine-producing cells in the gastric mucosa, and thickness of the mucus layer. RESULTS: Animals receiving treatment with the EPS-producing S. thermophilus CRL 1190 fermented milk showed a conserved gastric mucosa structure similar to that of healthy animals. In? ammation scores of the fermented milk-treated mice were lower than those of mice in the gastritis group (0.2 ± 0.03 vs 2.0 ± 0.6, P < 0.05). A marked decrease in INFγ+ (15 ± 1.0 vs 28 ± 1.2, P < 0.05) and TNF-α+ (16 ± 3.0 vs 33 ± 3.0, P < 0.05) cells and an increase in IL-10+ (28 ± 1.5 vs 14 ± 1.3, P < 0.05) cells compared to the gastritis group, was observed. Also, an increase in the thickness of the mucus gel layer (2.2 ± 0.6 vs 1.0 ± 0.3; 5.1 ± 0.8 vs 1.5 ± 0.4 in the corpus and antrum mucosa, respectively, P < 0.05) compared with the gastritis group was noted. A milk suspension of the purif ied EPS from S. thermophilus CRL1190 was also effective as therapy for gastritis.

关键词： Lactic acid bacteria Probiotics Gastritis Streptococcus thermophilus Exopolysaccharides

2型糖尿病的预测性遗传学检测可能引起不切实际的期望

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英国医学杂志中文版 2006年第6期9卷 331-332页

作者： A Cecile J W Janssens marta Gwinn Rodoffo valdez K M Venkat Narayan Muin J Khoury 谢超（译） Department of Public Health Erasmus MC University Medical CentreRotterdam 3000 CA Rotterdam Netherlands Centers for Disease Control and Prevention Atlanta GA 30341 USA 不详

今年年初,《纽约时报》头版头条报道了TCF7L2基因变异与2型糖尿病相关。主要研究者KariStefansson告诉《纽约时报》,这一发现可能会导致一种新的诊断性检测法产生,用于识别携带糖尿病变异基因的个体。他说,这将促使那些知道自己有糖尿... 详细信息

今年年初,《纽约时报》头版头条报道了TCF7L2基因变异与2型糖尿病相关。主要研究者KariStefansson告诉《纽约时报》,这一发现可能会导致一种新的诊断性检测法产生,用于识别携带糖尿病变异基因的个体。他说,这将促使那些知道自己有糖尿病高风险的人们避免采取引起糖尿病的生活方式。一位苏格兰科学家领导着该研究小组,《格拉斯哥先驱报》曾率先报道他们的工作,“糖尿病致病基因的发现将有助于科学家治疗糖尿病”。[第一段]

关键词： 2型糖尿病遗传学检测期望预测基因变异变异基因生活方式致病基因