RAPD-PCR molecular markers were used to identify common bean and soybean hybrid plants derived from crosses between closely related progenitors, with no apparent phenotypic differences. Primers OP-F12 and OP-0O3 were used to identify true hybrids derived from crosses between common bean cultivars Rudá (A 285) and AN 910408, and soybean cultivars Cristalina and Bossier, respectively. Each primer generated one polymorphic DNA band which was present in the male progenitor and absent in the female progenitor. As RAPD bands are normally inherited as dominant characters, the presence of these bands in the F1 plants confirmed their status

O pinhão-manso (Jatropha curcas L.) é uma planta oleaginosa que têm se destacado por apresentar as qualidades necessárias à produção de biodiesel. O objetivo deste trabalho foi adequar a metodologia do teste de envelhecimento acelerado, para a avaliação do potencial fisiológico de sementes de pinhão-manso. Para isto, quatro lotes de sementes foram, inicialmente, caracterizados, por meio do teor de água, percentagem e primeira contagem de germinação, percentagem e índice de velocidade de emergência de plântulas, germinação a baixa temperatura e altura da parte aérea. Os tratamentos utilizados foram três temperaturas (41ºC, 42ºC e 45ºC) e quatro tempos de exposição das sementes (24, 48, 72 e 96 horas), em cerca de 100% de umidade relativa do ar. O teste de envelhecimento acelerado conduzido por 24 horas, a 41ºC, foi eficiente para avaliar o vigor de sementes de pinhão-manso, permitindo a classificação dos lotes em níveis de vigor, à semelhança dos testes de primeira contagem de germinação, emergência de plântulas, germinação a baixa temperatura, índice de velocidade de emergência e altura da parte aérea de plântulas.

Common salt (99.3% of sodium chloride) is used as a water additive to reduce management stress in ornamental fish. Therefore, specific information on fish tolerance to water salinity is needed for establishing safe limits for salt use. In this study, we aimed to evaluate juvenile platy, Xiphophorus maculatus, for stress response and tolerance to acute salinity exposure. The fish were exposed to 0, 5, 10, 15, 20 and 25 g common salt/L water, for 96 h. Each aquarium containing 15 fish was considered an experimental unit. Mortality was quantified throughout the all‐experimental period, and blood glucose was measured at 24 and 96 h. Survival probability was high (>90%) in platy exposed to 0, 5 and 10 g common salt/L water. The median lethal concentration (LC50) was estimated at 16.54 g common salt/L water, by logistic regression analysis. Platy showed an increase in blood glucose at 24 h with increased salinity, but glucose levels decreased at 96 h of in fish exposed to 10 and 15 g/L. These findings suggest that short periods of exposure to common salt in water trigger stress responses in juvenile platy. Therefore, common salt should not be used in the handling and transport of platy, at the exposure times evaluated.

In statistical analyses of seed germination experiments, it is essential to ensure that the assumptions of the chosen methods are not violated to obtain valid and reliable results. When these assumptions are violated, alternative methods should be considered, one of which is survival analysis. This study aimed to evaluate the application of this methodology, using a nonparametric approach, to assess the germination of Cecropia pachystachya and Jacaranda caroba. In the first experiment, alternating temperatures of 30/20 °C and 25/15 °C were applied under two light conditions (light and darkness). In the second, germination was assessed at constant temperatures ranging from 15 to 35 °C. Germination reached or exceeded 50% in both species under alternating temperatures and light conditions. In continuous darkness, J. caroba exhibited a higher germination speed and percentages, whereas C. pachystachya was unaffected by light conditions. The recommended alternating temperature for both species was 30/20 °C. The optimal constant temperatures were 25 °C for J. caroba and 30 °C for C. pachystachya. It is concluded that the nonparametric survival analysis technique effectively discriminates seed germination of the studied species.

The use of silicates in plant tissue culture has resulted in positive effects regarding the morphological, anatomical and physiological characteristics of in vitro plants. However, biological responses to this mineral are dose and genotype dependent. The objective of the present study was to evaluate the influence of silicon supplementation on the somatic embryogenesis of oil palm (Elaeis guineensis Jacq.). The study was carried out in three stages of the cloning process, namely: Regeneration (i) and germination (ii) of somatic embryos and during ex vitro acclimatization (iii) of regenerated plantlets. The culture media were supplemented with four doses (0.0, 0.5, 1.0 and 1.5 g L^-1) of calcium silicate (CaSiO₃). The resulting plantlets were transplanted and acclimatized in a greenhouse. The regression analysis showed that the dose of 0.63g L^-1 of CaSiO₃ induced a higher rate of regeneration, which would allow a 58% increase in the number of somatic embryos formed. However, the germination of the plantlets, as well as their morphometric characters, were not affected by the different doses of CaSiO₃, although the presence of this compound promoted an increase in the thickness of the epidermis and a reduction in the amount of epicuticular wax. Overall, silicon does contribute to the cloning of E. guineensis.