Interspecific hybridization between Tigridia pavonia and T. augusta through ovary slice culture.

Tigridia pavonia is the most popular species in the Tigridia genus, and is currently marketed in Europe, Asia, and Australia as a landscape plant. Although it is native to Mexico, there are no breeding programs for it. In this study, we attempted to increase its flower color spectrum and growth habit by interspecific hybridization with T. augusta. Interspecific hybrids between T. pavonia and T. augusta were successfully obtained for the first time using the cut-style pollination and ovary slice culture techniques. On the contrary, no hybrids were obtained from a reciprocal cross. At three, four, and five days after pollination (DAP) ovaries were sliced and cultured on Murashige and Skoog medium without growth regulators and ammonium nitrate, but were supplemented with 6% sucrose, 50 mg/L yeast extract, and 0.25% Gelrite. After 80 days of culture initiation, the germination of only 10 embryos was observed in ovary slices cultured at three DAP. After transfer to identical fresh medium, six hybrid embryos developed into seedlings. All obtained hybrid seedlings were transplanted successfully to soil, and grew normally. The progenies investigated were identified as true hybrids based on randomly amplified polymorphic DNA analysis.

Genetic diversity of Cosmos species revealed by RAPD and ISSR markers.

The genus Cosmos is native of America and is constituted by 34 species; 28 of them are endemic of Mexico. The cosmos are used as a nematicide, antimalarial, and antioxidative agent. The aim of this study was to estimate the genetic diversity among 7 cosmos species based on random amplified polymorphic DNA (RAPD) and inter-simple sequences repeats (ISSR) markers. With RAPD markers, the obtained polymorphism was 91.7 % and the genetic diversity was 0.33, whereas these values were 65.6%, and 0.22 from ISSR markers, respectively, indicating the presence of high genetic diversity among the Cosmos species that were analyzed. The unweighted pair group method with arithmetic mean dendrograms that were obtained with both markers were notably similar, revealing 2 clusters and indicating a clear genetic differentiation among the Cosmos species that were assessed. The first cluster comprised the species Cosmos sulphureus, Cosmos pacificus, and Cosmos diversifolius, while the second cluster included the species Cosmos purpureus, Cosmos crithmifolius, Cosmos bipinnatus, and Cosmos parviflorus. Besides this, the Cosmos species were clustered according to their collection sites. The Mantel test corroborates the correlation between the genetic distance and the geographic altitude of each Cosmos species. The results suggest that it is necessary to preserve the Cosmos species in their natural habitat in addition to the germoplasm collection for ex situ conservation.

Spatial behavior comparison of Bactericera Cockerelli Sulc. (hemiptera: triozidae) in Mexico.

During the last five years, Bactericera cockerelli Sulc. has caused significant economic losses in potato production in Mexico, due to the purple top and zebra chip diseases, since it acts as the vector of Candidatus Liberibacter psyllaurous. Despite its importance as a vector of serious potato diseases, the knowledge of its spatial distribution behavior, which could improve the efficiency of control measures, is entirely lacking. The main objective of this work was to compare the spatial distribution of the immature and adult stages of B. cockerelli obtained in a potato field by means of transect and quadrant sampling techniques and of geostatistics tools that allow the visualization of its spatial distribution in the field. Transect and quadrant samplings showed that the immature stages (eggs and nymphs) of B. cockerelli present a clustered distribution. The validation of the achieved semivariograms in the three dates of sampling corroborated the aggregated distribution of immatures and adults of the insect. The maps obtained in the sampling by using the quadrant or the transect approaches reflect the aggregated structure of the insect populations which did not infest 100% of the plot area. This allowed us to identify infested and free areas, what will aid in decisions for selecting alternatives of control.

Cierre percutáneo de una malformación arteriovenosa pulmonar / Percutaneous treatment of pulmonary arteriovenous malformation

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¿Mejora el aporte proteico precoz el crecimiento extrauterino en recién nacidos pretérmino de bajo peso? / Does early parenteral protein intake improve extrauterine growth in low birth weight preterms?

Introducción: El retraso de crecimiento postnatal es frecuente en los recién nacidos pretérmino (RNPT) de bajo peso. La administración precoz de proteínas en su nutrición parece mejorar el crecimiento extrauterino y las comorbilidades asociadas. Evaluamos el impacto sobre el crecimiento posnatal de un nuevo protocolo de nutrición parenteral con aporte precoz de aminoácidos en recién nacidos < 1.500g. Material y métodos: Estudio observacional de casos-controles sobre una muestra de 58 RNPT < 1.500g. El grupo de casos lo formaron 29 RNPT que recibieron al menos 1,5g/kg/día de aminoácidos vía parenteral en las primeras 24h de vida, con aumentos diarios hasta alcanzar al menos 3,5g/kg/día al 3.°-4.° día, comparándose con un grupo control de 29 RNPT en los que el aporte de aminoácidos se inició el 2.°-3.° día de vida a 1g/kg/día, con incrementos menores diariamente. Valoramos la evolución somatométrica de ambos en el primer mes de vida. Resultados: No había diferencias en las características basales (sexo, edad gestacional, parámetros somatométricos) entre ambos grupos. Los RNPT que recibieron proteínas a dosis mayores y más precozmente tuvieron una ganancia de peso significativamente mayor que el grupo control (423±138g vs. 315±142g; p=0,005), presentando también una mayor velocidad de ganancia ponderal diaria (19,4±3,3 vs. 16,5±4,8; p=0,010) y una recuperación más precoz del peso al nacimiento (11,5±3,3 días vs. 14,5±4,5 días; p=0,045). No se observó mayor incidencia de complicaciones. Conclusiones: El aporte precoz de aminoácidos a dosis más altas mejora la ganancia ponderal en RNPT sin observarse un riesgo añadido para el paciente(AU)

Introduction: Extrauterine growth restriction affects most premature newborns. Early and higher parenteral protein intake seems to improve postnatal growth and associated comorbidities. We evaluate the impact of a new parenteral nutrition protocol based on early amino acid administration on postnatal growth in premature infants with a birth weight < 1,500 grams. Material and methods: A case-control study in 58 premature newborns with a birth weight < 1,500 grams. In the case group we included 29 preterm neonates who received at least 1.5g/kg/day parenteral amino acid during the first 24hours after birth, reaching a maximum dose of 3.5g/kg/day on the 3rd-4th day after birth. The control group was formed by 29 preterm neonates for whom protein support began on the 2nd-3rd day after birth with a dose of 1g/kg/day with lower daily increases than the case group. Growth rates and complications were followed until 28 days of life or discharge from NICU. Results: There were no differences between groups in baseline characteristics. Premature newborns who received higher and earlier doses of proteins had a greater weight gain than the control group, and this difference was statistically significant (423±138g vs. 315±142g; P=.005). In addition, they had a higher daily weight gain rate (19.4±3.3 vs. 16.5±4.8; P=.010) and they regained birth weight earlier (11.5±3.3 days vs. 14.5±4.5 days; P=.045). A higher incidence of complications was not observed. Conclusions: Early and higher amino acid administration improves growth rate in premature neonates with no apparent increase in risks for the patient(AU)