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Here we report, for the first time, the complete mitochondrial genome of Astyanax giton which, together with other species, are popularly known as tetras. The mitogenome’s length is 16,643 bp, containing 13 protein-encoding genes (CDS), two ribosomal RNAs (rRNA), 22 RNA transfer (tRNA) and one control region (D-loop). As for other vertebrates, all genes are encoded on the heavy strand except for ND6 and eight tRNA genes. In the phylogenetic analyses, this species and other Astyanax were paraphyletic.

Accelerated in vitro propagation of elite oil palm genotypes (Elaeis guineensis Jacq.) by substituting cytokinin with putrescine Clonal multiplication of oil palm enables the formation of commercial plantations with higher yield, which is possible through somatic embryogenesis. However, due to different modifications made in the existing protocols to avoid the appearance of the "mantled flower", the success of this technique has been limited. Thus, this study aimed to apply a cloning protocol, using somatic embryogenesis, to 32 elite oil palm genotypes from a commercial plantation on which cytokinin was substituted with putrescine. All tested genotypes responded positively to callus induction. Moreover, the percentages of responses were differentiated: 65.62% of these genotypes produced embryogenic lines, and 40.62% out of that percentage presented lines with moderate or high multiplication capacity, which is the main factor that enabled the obtaining of clones to form a commercial clonal plantation. The somatic embryogenesis was efficient, making this protocol applicable at a commercial scale, since it allows the obtaining of clones up to 360 days. However, future evaluations on these clones are needed to investigate the appearance of the "mantled flower".

RESUMOCinco descritores bioquímicos foram avaliados em algodoeiro infectados com o fungo causador da ramulose visando detectar respostas associadas à infecção. Sementes de quatro cultivares com diferentes níveis de resistência à doença foram semeadas em vasos plásticos, em casa de vegetação. Vinte dias após a emergência, as plântulas foram inoculadas com uma suspensão de 1 x 10 6 conídios/ mL de Colletotrichum gossypii var. cephalosporioides. Folhas foram coletadas aos 3, 15 e 30 dias após a inoculação e utilizadas para determinação de prolina livre, catalase, peroxidase, carboidratos solúveis e proteínas totais. Verificou-se que os teores de prolina livre, peroxidase e catalase foram discriminadores na reação de plantas infectadas. Estes descritores apresentaram rápida resposta nos primeiros dias após a infecção das plantas, sendo mais expressivo na cv. resistente BRS Antares. Os descritores prolina livre e catalase podem ser utilizados como ferramentas auxiliares na identificação de cultivares resistentes à ramulose nos programas de melhoramento da cultura do algodão. Palavras-chave: Gossypium, enzima, metabólitos, ramulose, resistência. ABSTRACT Biochemical descriptors of cotton cultivars in response to Colletotrichum gossypii var. cephalosporioidesFive biochemical descriptors were assessed in cotton plants infected with the ramulosis-causing fungus in order to detect differences associated with the infection. Seeds from four cotton cultivars with different levels of resistance were sown in plastic containers in greenhouse conditions. At 20 days after emergence, plants were inoculated with a suspension at 1 x 10 6 conidia/mL of Colletotrichum gossypii var. cephalosporioides. Leaves were collected at 3, 15 and 30 days after inoculation and free proline, catalase, peroxidase, soluble carbohydrates and total proteins were determined. Proline, peroxidase and catalase levels discriminated the reaction of infected plants. These descriptors changed soon after infection and the change was more evident in the resistant BRS Antares variety. Free proline and catalase descriptors can be used in the identification of ramulosis-resistant cultivars in cotton breeding programs. Keywords: Cotton disease, enzyme, metabolites, ramulosis. Na lavoura algodoeira, o custo com o controle de plantas invasoras, pragas e doenças chega a 30 -40% do custo total de produção (Freire, 2007). As doenças fúngicas estão entre os principais fatores responsáveis pela queda de produção da cultura. A ramulose, causada por Colletotrichum gossypii South var. cephalosporioides A.S. Costa, é uma das mais prejudiciais, podendo levar a perdas de até 60% na produção (Freire, 2007). O patógeno infecta as folhas, pecíolos e colmo provocando nanismo e superbrotamento dos ramos, o que prejudica a formação de maçãs e, conseqüentemente, o rendimento do algodão (Mehta et al., 2005).Muitas plantas desenvolveram mecanismos de defesa contra perturbações a que são submetidas ao longo do seu ciclo de vida. Algumas delas ativam mecanismos oxidativos buscando eliminar...

Salinity is one of the major environmental stress factors that affect crop productivity, as well as interfering with plant growth and development, resulting in reduced production quality. Given this, we highlight the importance of research in response to plants subjected to salt stress in order to assess the physiological and biochemical behavior of genotypes, with the objective of selecting the more tolerant. One way to ensure the uniformity of the response of the plants is through in vitro cultivation, which allows control of the cultivation conditions. Therefore, the objective of this work was to evaluate the response of two commercial varieties of sugar cane exposed to saline stress in different conditions (gradual and abrupt). Two varieties of sugarcane (RB931011 and RB872552) were subjected to in vitro salt stress by NaCl (56 mM and 112 mM), either gradually or suddenly. The responses of the enzymatic antioxidant system (catalase, peroxidases and ascorbate peroxidase) and free proline, as well as the Na + and K + contents, were assessed 30 days after the beginning of the treatments. Differences were observed in the responses of the varieties as a function of the induction mode of salt stress, graded or by shock, rather than as a function of the NaCl concentrations in the culture medium. The stress response is therefore conditioned not only by salt concentration, but also by the form of exposure to salt.Keywords: antioxidant enzymes, in vitro culture, oxidative stress, salinity. RESUMENLa salinidad es uno de los principales factores de estrés ambiental, además de interferir en el crecimiento de las plantas perjudica directamente la producción agrícola. En ese contexto, se destaca la importancia de investigaciones direccionadas a la respuesta de las plantas sometidas al estrés salino, con el fin de evaluar el comportamiento fisiológico y bioquímico con el objetivo de seleccionar genotipos tolerantes a dicha condición. Una de las técnicas más utilizadas para uniformizar la respuesta de las plantas a una condición en particular es el cultivo de tejidos in vitro. Por lo tanto, el objetivo de este estudio fue evaluar la respuesta de dos variedades comerciales de caña de azúcar (RB931011 e RB872552) expuestas a estrés salino con NaCl (56 mM e 112 mM) en diferentes condiciones, gradual y abrupta. Las respuestas del sistema antioxidante enzimático (catalasa, peroxidasa y ascorbato peroxidasa) y prolina libre, asi como las concentraciones de Na + e K + fueron evaluadas 30 días después del inicio de los tratamientos. Fueron observadas diferencias en la respuesta de las variedades en función del modo de inducción del estrés salino, graduado o abrupto, y no solo en función de las concentraciones de NaCl en el medio de cultivo. La respuesta al estrés es condicionada no solo por la concentración de sal sino también por la forma de exposición al medio salino.Palabras clave: cultivo in vitro, enzimas antioxidantes, estrés oxidativo, salinidad.

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