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This paper describes the effect of the various plant growth regulators of the culture medium on morphogenic processes in vitro in Cinchona officinalis L, a highly vulnerable species from southern Ecuador. To do this, different concentrations of NaOCl were used in combination with different immersion times for seed disinfection; for seed germination in vitro GA3 was added to the MS basal culture medium in different concentrations, and for morphogenic processes in vitro, different concentrations of auxins and cytokinins were combined. The decrease in the contamination rate was with high concentrations of NaOCl and an increase in the germination rate in 45 days with the addition of 1.0 mg L-1 GA3 to the culture medium the hormonal combination of 0.5 mg L-1 NAA + 2.5 mg L-1 BAP showed a high rate of shoot proliferation and with 1.0 mg L-1 NAA a high number of roots was obtained. In the callogenesis phase, the best results were obtained with 1.0 mg L-1 2,4-D + 0.5 mg L-1 BAP for callus proliferation. In vitro propagation protocols were generated in Cinchona officinalis L, for the preservation and conservation of the species. [ABSTRACT FROM AUTHOR]

The objective of this work was to determine a glyphosate formulation effects on the root length reduction (average effective concentration: EC50) using germination bioassays with lettuce and wheat seeds. For lettuce nine decreasing doses/treatments between 1,215 and 0.01215 g a.i.ha-1 (formulated as: N phosphonometyl glycine ammonium salt 40.5 [g e.a. glyphosate 36.9% p/v]) and for wheat five decreasing doses (12.15 and 1.215 g a.i.ha‑1) and their respective negative controls (distilled water) were tested. Bioassays were carried out in Petri boxes with wet filter paper with 3 ml of corresponding solution. Twenty seeds were sowed per box, treatments being distributed in blocks at random with 4 repetitions in germination chamber under alternating light and dark condition at 20°C. All seed average root length and repetition were estimated with a digital caliper. The average germination percentage of treatments and the germination index was also determined. EC50 or doses reducing 50% their radical growth for lettuce and wheat were 6.682 and 9.416 g a.i.ha-1. Plant materials tested resulted sensitive to the different glyphosate doses and they can be used as biological indicators of the specific toxicity. [ABSTRACT FROM AUTHOR]

In the North of the Entre Ríos province, a model for rice production has been developed, based in the use of superficial water from more than 60 land dams with variable surfaces. The usage of agrochemicals in the area might bring a contamination factor to the soil and dam water. The objective of this work was to determine water quality from 19 irrigation dams situated in the Central North of the Entre Ríos province through germination bioassays of Lactuca sativa, butterhead variety. Bioassays were carried out in Petri boxes with filter paper at the bottom, wet with 3 ml of corresponding sample water. Twenty seeds were sowed per box, treatments being distributed in blocks at random with 4 repetitions in germination chamber under alternating light and dark condition. Germination percentage was recorded and the average root length; a germination index was estimated. The average germination percentage of treatments was 96.07% and 97.9% in the control treatment. The germination index in all cases was higher than 60% and toxicity was not detected in the water from different dams. [ABSTRACT FROM AUTHOR]