Effect of storage of achenes of Bidens gardneri Baker on light sensitivity during germination

Bidens gardneri is a very common herbaceous species in the cerrados of the state of São Paulo, whose seeds become light sensitive at 25°C only. Achenes of this species were stored in refrigerator at 4°C and in cerrado soil and in forest soil. The field experiments were carried out in the cerrado at the Reserva Biológica e Estação Experimental de Moji Guaçu, in Moji Guaçu and in the forest of the Instituto de Botânica, in São Paulo, Brazil. Achenes of B. gardneri vary in size and achenes from 7 to 12 mm long were used. Achenes stored for up to 6 months at 4°C showed light sensitivity; after 9 months storage, the difference in germination between light and darkness had disappeared for the smallest and the largest achenes used. Seeds of B. gardneri germinated during the period of storage in soil; the number of germinated seeds increased over the storage time, while the number of intact achenes decreased for the same period, no matter if the experiment was being carried out in the cerrado or in the forest. Therefore, the achenes germinated in soil in darkness. Light sensitivity was lost in intact achenes that had been stored in soil for three months.

Incidence of heart failure in infarcted rats that die spontaneously

The present study reports for the first time the incidence of congestive heart failure (CHF) in previously infarcted rats that died spontaneously. Previously, pulmonary (PWC) and hepatic (HWC) water contents were determined in normal rats: 14 control animals were evaluated immediately after sacrifice, 8 placed in a refrigerator for 24 h, and 10 left at room temperature for 24 h. In the infarcted group, 9 rats died before (acute) and 28 died 48 h after (chronic) myocardial infarction. Thirteen chronic animals were submitted only to autopsy (N = 13), whereas PWC and HWC were also determined in the others (N = 15). Seven rats survived 48 h and died during anesthesia. Notably, PWC differed in normal rats: ambient (75.7 ± 1.3%) < control (77.5 ± 0.7%) < refrigerator (79.1 ± 1.4%) and there were no differences with respect to HWC. No clinical signs of CHF (dyspnea, lethargy or foot edema) were observed in infarcted rats before death. PWC was elevated in all chronic and anesthetized rats. HWC was increased in 48% of chronic and in all anesthetized rats. Our data showed that PWC needs to be evaluated before 24 h post mortem and that CHF is the rule in chronic infarcted rats suffering natural death. The congestive syndrome cannot be diagnosed correctly in rats by clinical signs alone, as previously proposed.

Storage of Tabebuia caraiba (Mart.) Bureau seeds in different packaging and temperatures

Tabebuia caraiba (Mart.) Bureau, commonly known as Silver Trumpet Tree is a forestal species, belonging to Bignoniaceae family, which can be utilized as medicinal plant or in landscaping of urban and rural areas; besides producing large mechanical resistance wood. Despite its wide use and ecological importance, basic studies on storages of their seeds are scarce. This way, the objective of this study was to determine the most adequate packaging and the best temperatures, for storing seeds of T. caraiba. For this, seeds were stored in two types of packaging: Kraft paper bags and transparent polyethylene bags; which were then stored during 150 days under three different environments: laboratory normal environment (25±2 °C); cold chamber (8±2 °C); and refrigerator (6±2 °C). After periods of 0, 30, 60, 90, 120, and 150 days, seed moisture content, percentage of emergence, emergence speed index, and seedling length were evaluated. Seeds of T. caraiba kept in packaging of paper and polyethylene bags and stored at laboratory environmental condition, have lost more quickly their vigor along the storage period. For storage, it is recommended the maintenance of T. caraiba seeds in polyethylene bags into cold chamber; and/or polyethylene bags or Kraft paper bags into refrigerator.