Densidad seca al aire y características cuantitativas de elementos xilemáticos de conducción en 10 especies de Malvaceae en Venezuela

Se presenta el estudio de la relación entre la densidad seca al aire y características cuantitativas de los vasos (frecuencia y diámetro de vasos, área de lumen) para diez especies de Malvaceae que crecen en Venezuela: Catostemma commune, Eryotheca globosa, Ochroma pyramidale, Pachira quinata, Guazuma ulmifolia, Apeiba tibourbou, Heliocarpus americanus, Uladendron codesurii, Sterculia apetala y Sterculia pruriens. La densidad se determinó en muestras acondicionadas al 12 % de humedad y para la medición de las características de los vasos se prepararon láminas de secciones transversales utilizando los procedimientos convencionales de microtecnia xilemática. Las mayores frecuencias y menores diámetros de vasos se presentaron en Guazuma ulmifolia y Uladendron codesurii; mientras que las menores frecuencias y mayores diámetros de vasos los presentaron especies de las subfamilias Bombacoideae y Sterculioideae. La densidad seca al aire mostró un alto grado de variación, encontrándose especies que van desde la categoría de muy baja densidad (Ochroma pyramidale, Pachira quinata, Apeiba tibourbou, Heliocarpus americanus, Sterculia apetala) hasta muy alta densidad (Uladendron codesurii). La relación entre la densidad y las características de los vasos presentó una baja correlación lo que indica la posible existencia de otras características anatómicas que ejercen mayor influencia sobre esta propiedad física.

Efecto de la nutrición focalizada ultra corta con vainas de leguminosas tropicales en la respuesta reproductiva de ovejas de pelo o lana / Effect of ultra-short focused nutrition with tropical legume pods on the reproductive response of sheep with hair or wool

El uso de biotecnologías reproductivas, permiten mejorar la productividad de los ovinos, esto combinado con nutrición focalizada de corta duración con fuentes energéticas o proteicas pueden generar sinergia en los resultados. En las regiones tropicales, el uso de vaina de leguminosas representa una alternativa nutricional en rumiantes. Por lo que, el objetivo de esta investigación fue conocer el efecto de las vainas de dos leguminosas tropicales; Leucaena leucocephala y Guazuma ulmifolia, bajo la hipótesis de que su uso mejora la repuesta reproductiva en ovejas de pelo o lana. El experimento se realizó en el Colegio de Posgraduados, Montecillo, Texcoco, México. Se utilizaron 48 ovejas de pelo y 27 de lana, en libre pastoreo, distribuidas en 4 tratamientos, el T1 y T3 se les ofreció 350 gr de vainas de leguminosas por seis días antes del servicio, todas las ovejas se sincronizaron con progestágeno y prostaglandinas, Las variables no paramétricas se analizaron con el método de curvas de sobrevivencia Log-Rank, utilizando el procedimiento Life Test (SAS, 2011); y la comparación de medias se realizó por el método de Bonferroni (SAS, 2011). El porcentaje de celos no mostro diferencia (P0.05), mientras que horas al celo, porcentaje de gestación y prolificidad mostró diferencia (P0.05) entre tratamientos, en favor de T1 y T3. Se concluye que el uso de vainas de leguminosas en nutrición focalizada ultracorta mejora la respuesta reproductiva de ovejas.

Criterios de uso y conservación de árboles en potreros basados en el conocimiento local de los ganaderos en una zona de bosque seco tropical en Colombia

Trees are attributed an important role in livestock farms, fulfilling various functions. The study documents the retention of woody species in cattle farms from local and technical knowledge in the upper part of the Magdalena river basin, Colombia. 195 semi-structured questionnaires were applied to identify the perception of producers about the classification and uses of tree forage species, based on physical, nutritional, phenological and environmental criteria, as indicators of conservation and use of species in pastures. With these indicators, indices were constructed that identified important characteristics of the species mentioned by the ranchers. Data were analyzed with descriptive statistics, mean comparisons, and multivariate analysis techniques. It is recognized that producers appreciate species based on criteria of use and functions related to their productive activity. Six highly valued species Gliricidia sepium, Guazuma ulmifolia, Pithecellobium dulce, Albizia guachapele, Acacia farnesiana and Albizia saman coincide with other studies of local knowledge. The study provides relevant information on twelve species associated with livestock, which have not been reported in previous studies, so it suggests deepening and complementing with scientific knowledge to recognize and assess the use of these potential species for livestock production, allowing interaction between knowledge in a concerted technological system.

PENGARUH PEMBERIAN TEH KOMBUCHA DAUN JATI BELANDA (Guazuma ulmifolia Lamk ) TERHADAP PENURUNANAN KADAR TRIGLISERIDA DARAH TIKUS PUTIH JANTAN (Rattus norvegicus)

Teh kombucha merupakan tinggi antioksidan dan mampu membantu menurunkan kadar trigliserida dengan cara meningkatkan aktivitas enzim lipoprotein lipase yang dapat bekerja memecah trigliserida. Studi sebelumnya mengatakan bahwa daun jati belanda (Guazuma ukmifolia, Lamrk) mampu menurunkan kadar lipid darah karena kandungan tanin dan mucilago yang mampu mengurangi absorpsi lemak. Tujuan Penelitian ini untuk mengetahui efek pemberian teh kombucha daun jati belanda mampu menurunkan angka trigliserida (TGD) darah tikus putih jantan. Metode penelitian ini berupa eksperimental meliputi pengumpulan bahan, pembuatan simplisia, skrining fitokimia, fermentasi kombucha daun jati belanda, evaluasi mutu sediaan, pengujian kadar trigliserida pada tikus dengan teknik Elektrode-Based Biosensor. Penelitian ini dibagi menjadi 5 (lima) kelompok yaitu: P1; P2; P3, P4 dan P5, pemberian obat dan dilakukan secara oral kepada 25 ekor tikus yang telah diinduksi menggunakan kuning telur 80% dan propiniltiourasil (PTU 0,2%). Penelitian ini dibagi menjadi 5 kelompok yaitu kontrol positif simvastatin 0,025% diberikan sebanyak 1,44 ml (P1); kontrol negatif kombucha tanpa sampel (blanko) diberikan sebanyak 3,6 ml (P2); kelompok perlakuan teh kombucha daun jati belanda berturut-turut 100 ml/gBB diberikan sebanyak 1,8 ml (P3); 150 ml/gBB diberikan sebanyak 2,7 ml (P4); 200 ml/gBB diberikan sebanyak 3,6 ml (P5). Hasil penelitian menunjukkan pada kelompok perlakuan 200 ml (P5) pada hari ke-7 sampai hari ke-15 terjadi penurunan angka TGD dari 246,8 mg/dL menjadi 93 ml/dL dengan persentase penurunan trigliserida diperoleh 37,68%, dimana hasil ini mendekati angka kontrol positif (P1) dari 238,6 mg/dL menjadi 84 mg/dL dengan persentase penurunan trigliserida diperoleh 35,20%. Pada pengujian kadar trigliserida pada kelompok percobaan, didapatkan hasil yang berbeda pada tiap kelompok percobaan. Hasil pengujian kadar trigliserida yang di dapatkan, selanjutnya dilakukan uji statistika berupa non parametrik dengan menggunakan metode khurskal wallis, dari hasil pengujian didapatkan hasil p=0.098 (p=0,05) yang menunjukan bahwa data terdistribusi secara normal

Basic density and CO2 sequestration in seven species from the Commemorative Arboretum of 500 Years of Brazil in Alberto Löfgren State Park, São Paulo

Carbon sequestration involves the removal of CO2 from the atmosphere, aiming to reduce the greenhouse effect. Wood basic density is a direct part of this process. We selected five trees in each of the following species to determine wood basic density and quantify carbon, both sequestered and fixed, for 10 years: Alchornea sidifolia, Ceiba speciosa, Gallesia integrifolia, Guazuma ulmifolia, Inga marginata, Maclura tinctoria, and Prunus cerasoides. The study was conducted in the Commemorative Arboretum of 500 Years of Brazil in Alberto Löfgren State Park, São Paulo. Using maximum moisture content capture of CO, we studied variations of wood density and CO2, both fixed and sequestered, by an individual tree in the same species and between species. Values of fixed and sequestered CO2 showed variations among species with a high dependence on wood density such that trees with higher amounts of CO2, both fixed and abducted, were also trees that showed the highest increment both in height and diameter (DBH). Based on these metrics, G. ulmifolia, I. marginata, M. tinctoria, and P. cerasoides showed the most potential to sequester carbon. Our calculations showed that planting these four species would result in the sequestration of around 30 tons of carbon per hectare.

Características higroscópicas de ocho maderas mexicanas

El objetivo de la investigación fue determinar la densidad básica, el contenido de humedad inicial, el máximo contenido de humedad, el punto de saturación de la fibra, el porciento de pared celular y el porciento de espacios vacíos de ocho maderas mexicanas: Cupressus lindleyi, Cedrela odorata, Swietenia macrophylla, Tabebuia donnell-smithii, Fraxinus uhdei, Fagus mexicana, Dalbergia palo-escrito y Guazuma ulmifolia. La variabilidad de las características higroscópicas de las maderas estudiadas puede explicarse por las diferencias en las particularidades anatómicas propias de cada especie. Sin embargo, sus correlaciones estadísticas, así como sus magnitudes se sitúan en los rangos reportados en la bibliografía.

Organization of leaf vascular system and gas exchange in seedlings of Guazuma ulmifolia Lam. in different light conditions

In tropical forests, different physiological characteristics of leaves in tree species are evidenced by variations in different incident light conditions. We aim to evaluate gas exchange and organization of leaf vascular system in Guazuma ulmifolia Lam. seedlings under different light conditions. Seedlings were obtained from seeds germinated under greenhouse conditions with controlled environment. Ninety days after germination, seedlings in 8kg pots were transferred to the experimental site to allow acclimatization under sun and shade conditions. The experimental design was completely randomized, with two treatments: full sunlight and artificial shading, limiting the luminosity to about 5% of irradiance. Seedlings were maintained under these conditions for 120 days before measuring gas exchange parameters. We measured photosynthetic rate, stomatal conductance, sub-stomatic CO2 concentration, transpiration, and chlorophyll content. Anatomical analysis measured distance between veins, distance from veins to abaxial epidermis, distance from veins to adaxial epidermis, distance from veins to stomata, total leaf thickness, abaxial epidermis thickness, adaxial epidermis thickness, palisade parenchyma thickness, and spongy parenchyma thickness of foliar gas exchange of G. ulmifolia which presented significant differences between light environments. Photosynthetic rate and stomatal conductance were reduced by 78% and 39%, respectively, in shade, while stomatal conductance increased by 31% in full sunlight. Transpiration showed no significant difference between the two treatments, but chlorophyll content was 30% lower in full sunlight. Distance between veins and distance from veins to stomata showed no difference between treatments, but the other parameters increased in full sunlight. Thus, the results showed that the pioneer species G. ulmifolia presented leaf gas exchange acclimated to environments with high luminosity.

Wood hydraulic characteristics of pioneers/early secondary and non-pioneer species

We aimed to determine any differences in hydraulic conductivity between pioneer species/early secondary and non-pioneers. To make this determination, we measured maximum vessel length (Mvl), specific hydraulic conductivity (Ks), percentage of embolized vessels (Pev), leaf hydraulic conductivity (Kl) and wood density at equilibrium moisture content-12% (Wd12). The pioneer/early secondary species we examined were Guazuma ulmifolia, Inga marginata and Maclura tinctoria. The non-pioneers we examined were Paubrasilia echinata, Cariniana legalis and Myroxylon peruiferum. The results were submitted to statistical analyses, including multiple comparison tests and t test, to verify differences between successional groups and regression analysis to verify the relationship between Ks and the other variables. Pioneer species had higher Ks than non-pioneers. Non-pioneers had a higher percentage of embolized vessels and wood density. Successional groups did not differ in Mvl, which is positively related to hydraulic conductivity in both successional groups since the percentage of embolized vessels was related negatively. Wood density is positively related to Ks in non-pioneer species, while a negative correlation was observed between Ks and Kl in the pioneer species.

Etnobotânica sobre plantas medicinais na localidade do Jombe I - Conda, Cuanza Sul - Angola

Angola é um estado rico em diversidade cultural e em recursos florísticos. Todavia, o conhecimento autóctone e a conservação destes recursos carecem de estudos profundos, por esta razão tem sido preocupação da comunidade científica tornar este conhecimento empírico em científico. Assim, partindo dos aspectos botânicos, ecológicos e culturais, desenvolveu-se de setembro de 2019 à março de 2020, um estudo etnobotânico no Jombe I, Conda, Cuanza-Sul, Angola - cujo objetivo foi recolher informação etnobotânica, das plantas medicinais utilizadas nesta localidade. Baseou-se na Etnografia, Antropologia e Botânica, combinando as técnicas de entrevista, observação participativa e herborização. Realizou-se 17 entrevistas que resultaram a percepção de 94 etnoespécies. Os informantes foram as autoridades tradicionais, Ervanários aposentados, parteiras tradicionais e as entidades eclesiásticas. Este trabalho resultou na coleta de 76 espécies de plantas, para identificação científica e herborização no ISPCS. Destas, 69 foram identificadas. Estas pertencem a 33 famílias e 29 taxas. A Fabaceae (42%), Asteraceae e Malvaceae (12,12%) foram as famílias representativas. A Steganotaenia araliacea (92,31%), Chenopodium ambrosioides (84,62%) e Guazuma ulmifolia (61,54%) foram as espécies mais citadas. Quanto ao uso medicinal a Cochlospermum angolense, Chenopodium ambrosioides e a Steganotaenia araliácea são as mais utilizadas.