Poejo (Cunila galioides Benth. ) Production in Five Agroecological Regions of Rio Grande do Sul

Abstract The objective of this study was to evaluate the biomass and essential oil production of nine populations of poejo (Cunila galioides) cultivated in five agroecological regions of the state of Rio Grande do Sul, under different edaphoclimatic conditions. The experiments were performed in field conditions in Erechim, Caxias do Sul, Pelotas, São Francisco de Paula, and Santa Vitoria do Palmar. The experimental design was completely randomized, with nine populations, eight plants per plot and four repetitions. The following were evaluated: biomass production and essential oil chemical composition and yield. The data underwent ANOVA, followed by Tukey's multiple range test. The adaptability and stability of the populations in the different environments were also evaluated by regression analysis. The results showed great differences between the populations and cultivation sites, with genotype vs. environment interaction. Most populations presented the best biomass production results at Erechim. Pelotas and Santa Vitória do Palmar were the worst locations for poejo production, mainly due to a water deficit occurred during the experiment. The Santa Lucia population presented broad stability and the greatest adaptability to the environments for biomass and essential oil production, but its average production was not satisfactory. The André da Rocha population presented the highest average production of essential oil, and was favored in favorable environments. Regarding essential oil chemical composition, the populations kept stable contents of the major compounds at all locations, with a few variations. In some populations, a higher concentration of sesquiterpenes was observed, which can be attributed to environmental stress.

Influence of abiotic environmental factors on the main constituents of the volatile oils of Tithonia diversifolia

ABSTRACT Tithonia diversifolia (Hemsl.) A. Gray, Asteraceae, commonly known as Mexican sunflower, is a wide distributed invasive species encountered around the world. We proposed herein to establish the relationship between different abiotic environmental factors and the variation in the production of volatile compounds in T. diversifolia, during a period of one year. Samples of leaf and inflorescence volatile oils obtained from individuals located at two different regions of Brazil were analyzed by GC-MS and the data were submitted to chemometric analysis. Based on the main constituents, the analysis allowed us to classify the volatile oils into two chemotypes, according to their geographical origin. The influence of soil nutrients, mainly Ca and P, was also observed in the composition of the volatile oils. Climate also seems to affect the constituents of the volatile oils, mainly the contents of leaf sesquiterpenes of individuals growing in areas with higher average temperatures and solar radiation levels. We can therefore highlight that the appropriate multivariate statistical analysis allowed us to propose for the first time the existence of chemotypes for the volatile oils of T. diversifolia, as well as reporting the main abiotic environmental factors related to the accumulation of the discriminant compounds in these oils.

Influence of environmental factors on the composition of essential oils from leaves of Myrcia tomentosa (Aubl) DC / Influencia de los factores ambientales sobre la composición de los aceites esenciales de hojas de Myrcia tomentosa (Aubl) DC

The leaves of Myrcia tomentosa were collected from five sites and four different months in the Brazilian Cerrado and their essential oils were obtained by hidrodistillation and analyzed by GC/MS. The aim of this work was to evaluate the influence of environmental factors on essential oils composition in the leaves of M. tomentosa. The results were submitted to stepwise Multiple Regression and Canonical Correlation Analysis that indicated a relationship between compounds in essential oils and some environmental factors (foliar nutrients, soil nutrients and climatic data). Cluster Analysis indicated a high chemovariability in the essential oils from different sites, also showed that the collection time had a minor effect on oil composition.

Las hojas de Myrcia tomentosa se obtuvieron de cinco sitios diferentes y cuatro meses en el Cerrado brasileño y sus aceites esenciales fueron obtenidos por hidrodistillation y analizados por GC/MS. El objetivo de este trabajo fue evaluar la influencia de los factores ambientales sobre la composición de los aceites esenciales en las hojas de M. tomentosa. Los resultados fueron sometidos a múltiples etapas de regresión y análisis de correlación canónica indicó que la relación entre los compuestos en los aceites esenciales y algunos factores ambientales (nutrientes foliares, fertilizantes y datos climáticos). El análisis de agrupamiento indicó chemovariability un alto en los aceites esenciales de diferentes sitios, también mostró que el equipo de recolección tuvo un efecto menor sobre la composición del aceite.

Genetic and environmental influences on blood pressure and physical activity: a study of nuclear families from Muzambinho, Brazil

Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers and 122 mothers (24 to 65 years) were evaluated. BP was measured, and total PA (TPA) was assessed by an interview (commuting, occupational, leisure time, and school time PA). Quantitative genetic modeling was used to estimate maximal heritability (h²), and genetic and environmental correlations. Heritability was significant for all phenotypes (systolic BP: h² = 0.37 ± 0.10, P < 0.05; diastolic BP: h² = 0.39 ± 0.09, P < 0.05; TPA: h² = 0.24 ± 0.09, P < 0.05). Significant genetic (r g) and environmental (r e) correlations were detected between systolic and diastolic BP (r g = 0.67 ± 0.12 and r e = 0.48 ± 0.08, P < 0.05). Genetic correlations between BP and TPA were not significant, while a tendency to an environmental cross-trait correlation was found between diastolic BP and TPA (r e = -0.18 ± 0.09, P = 0.057). In conclusion, BP and PA are under genetic influences. Systolic and diastolic BP share common genes and environmental influences. Diastolic BP and TPA are probably under similar environmental influences.

Alterations in ambient salinity and pH lead to modulation of developmental gene expression in Microhyla ornata (Duméril and Bibron) and Xenopus laevis (Daudin).

Naturally fertilized Microhyla ornata and Xenopus laevis embryos at dorsal lip of blastopore stage were exposed to 0.3, and 0.6% sodium chloride for high salinity treatment and dilute hydrochloric acid and sodium hydroxide for treatment with low and high pH, respectively. After treatment for different durations, embryos were studied morphologically and using in situ hybridization with selected genes important for normal development and for coping with environmental stress. Altered salinity and pH caused defects in axis formation and neural tube closure, delay in hatching, abnormal swimming of tadpoles and even developmental arrest. This was accompanied by significant decrease in the expression of selected development-regulating genes like goosecoid (required for gastrulation movements), brachyury (mesodermal marker gene), noggin (involved in neural induction), NCAM (required for neural cell adhesion) and MyoD (essential for muscle development), and considerable increase in the transcription of stress response genes hsp30 and hsp70. Altering the expression of embryonic genes could be one of the mechanisms through which environmental factors influence development of amphibian embryos.