Prediction of soil seed bank of piedmont and alluvial environments of Dera Ghazi Khan, Punjab, Pakistan / Predição do banco de sementes do solo do piemonte e ambientes aluviais de Dera Ghazi Khan, Punjab, Paquistão

Abstract The current focus is on the overall pattern of seed storage present in the fragments of the soil of piedmont and alluvial landscapes of the environment. The present study predicted the seed banks of both soils of alluvial and piedmont zones in different ecological conditions and evaluate the potential of seeds in the restoration of both environments. The composition of the seed bank of soil is mainly affected by the alluvial environment and the structure of cleared area shows that more species of germinating annual grasses and growable seeds with the higher total number. Extant vegetation structures have an important role in the diversity of soil seed reservoirs, whose composition corresponded with the openness of the site. When in situ soil seed bank is recruited, it helps to restore only some components of the plant community in an alluvial environment. In our current research, it was confirmed that seed richness was higher in number at lower elevation (alluvial) than that at high elevation (piedmont). Seed richness showed a significant negative correlation with anions, cations, while significantly positive with altitude that suggests the richness pattern of the overall seed bank of the area is influenced by various environmental factors.

Resumo O foco atual está no padrão geral de armazenamento de sementes presente nos fragmentos de solo do Piemonte e nas paisagens aluviais do meio ambiente. O presente estudo previu os bancos de sementes de ambos os solos das zonas aluvial e piemontesa em diferentes condições ecológicas e avaliou o potencial das sementes na restauração de ambos os ambientes. A composição do banco de sementes do solo é afetada principalmente pelo ambiente aluvial e a estrutura da área desmatada mostra que mais espécies de gramíneas anuais em germinação e sementes cultiváveis ​​apresentam o maior número total. As estruturas da vegetação existente têm um papel importante na diversidade dos reservatórios de sementes do solo, cuja composição correspondeu à abertura do local. Quando o banco de sementes do solo in situ é recrutado, o mesmo ajuda a restaurar apenas alguns componentes da comunidade de plantas em um ambiente aluvial. Em nossa pesquisa atual, foi confirmado que a riqueza de sementes era maior em número em altitudes mais baixas (aluviais) do que em altitudes elevadas (Piemonte). A riqueza de sementes mostrou uma correlação negativa significativa com ânions, cátions, enquanto significativamente positiva com a altitude, o que sugere que o padrão de riqueza do banco geral de sementes da área é influenciado por vários fatores ambientais.

Genetic variability of cocoa from the amazon basin: implications for genetic conservation

The cocoa and chocolate production chain involves US$60 billion annually and three million farmers around the world, in an area exceeding nine million hectares. The use of wild germplasm will enable to generate new disease- and pest-resistant cultivars and ability to adapt to changing environments. Here we evaluated 145 cocoa accessions, originated from nine Amazonian basins, based on eight fruit traits. Univariate anova showed significant differences (p<0.05) for all traits. For seven traits, the variance component within basins was higher (81.5%, on average). Therefore, it is recommended that the collection of wild accessions prioritize a larger number of plants from a few populations of the most divergent basins. The multivariate analyses revealed a greater divergence between the Ji-Paraná-RO and Solimões/Amazonas-PA basins (27.69) and a greater similarity between Alien clones-PER and Solimões/Amazonas-AM (0.66) in relation to their populations. They also revealed that the accessions differentiation occurred according to the river basin system. These results allowed elucidate the genetic structure and distribution of cacao populations. In addition, strengthen the importance of collecting and conserving germplasm to preserve genetic resources.

Seasonal variation of essential oil of germplasm of Lippia origanoidesKunth. (Verbenaceae) / Variación estacional de aceite esencial de germoplasma de Lippia origanoidesKunth. (Verbenaceae)

The biological activities attributed to Lippia origanoides Kunth. vary according to the chemical composition of its essential oil, which can be related to weather factors. The aim of this research was the seasonal study of the essential oil chemical composition taken from L. origanoides accessions maintained in germplasm bank in vivo. The essential oil was extracted by hydrodistillation in Clevenger apparatus and identification of the components was done by GC-MS. We have identified 15 compounds of which carvacrol, p-cymene, thymol and methyl-ether-thymol were majority throughout the year for most accessions. In three accessions showed fluctuations in the production of the major compound during the year like the α-pinene, limonene and borneol. The essential oil showed variation in chemical composition throughout the year, the major compound in most of the accessions during the year is carvacrol. In some accessions, there are alterations of the majority component.

Las actividades biológicas atribuidas a Lippia origanoides Kunth. varían según la composición química de su aceite esencial, lo que puede estar relacionado con factores climáticos. El objetivo de esta investigación fue el estudio estacional de la composición química del aceite esencial extraído de accesiones de L. origanoides mantenidas en banco de germoplasma in vivo. El aceite esencial se extrajo mediante hidrodestilación en un aparato Clevenger y la identificación de los componentes se realizó mediante GC-MS. Hemos identificado 15 compuestos de los cuales carvacrol, p-cimeno, timol y metil-éter-timol fueron mayoritarios durante todo el año para la mayoría de las accesiones. En tres accesiones se observaron fluctuaciones en la producción del compuesto principal durante el año como el α-pineno, limoneno y borneol. El aceite esencial mostró variación en la composición química a lo largo del año, el compuesto principal en la mayoría de las accesiones durante el año es el carvacrol. En algunas accesiones, hay alteraciones del componente mayoritario.

Germplasm screening of Myrtus communius Var. Italica l. for cultivar development from dir lower (Malakand Division), Pakistan

Habb-ul-Aas is a commercial drug obtained from Myrtus communis L and widely used for abdominal disorders in Pakistan. This sclerophyllous shrub is commonly found in the Lower Dir, Malakand Division, Pakistan. This plant is used as crude drug in herbal as well as pharmaceutical industry due to presence of aromatic oil obtained from various parts of the plant. Two varieties viz., italic and baetica of the plant exist in the world; however, no study reported before about the existence of this species up to the varietal level from Pakistan. The current study was undertaken to characterize the existing germplasm by using certain morphometric parameters in relation to physiognomic features. They exhibit high variability among characters, especially for characteristics useful in selecting cultivars for commercial production. Among the various ecotypes, MBT3 possessed high shoot length (29.96cm), leaf area (2.3cm), fruit volume (0.97ml) & fruit weight (0.88g) and pulp (0.87g) and therefore recommended for the cultivar development.

Seasonal variation in the essential oil from Varronia curassavica jacq. accessions / Variación estacional en el aceite esencial de accesiones de Varronia curassavica Jacq

Varronia curassavica has anti-inflammatory properties because of the terpenes, α-humulene and ß-caryophyllene, present in the essential oil. The objective of this study was to evaluate the influence of seasonality on the essential oil of V. curassavica accessions. Leaves from six accessions were collected from the Germplasm Bank of the Federal University of Minas Gerais over 12 months. Correlations between the essential oil content and meteorological factors were determined. Gas chromatography analysis coupled with mass spectrometry was conducted to determine the chemical composition of the essential oil. The content and chemical composition of the oil varied throughout the year. Relative humidity was correlated with accessions ICA-VC2 (-0.64) and ICA-VC4 (0.68). ß-bourbonene, ß-elemene, spathulenol, germacrene, caryophyllene oxide, α-humulene, and ß-caryophyllene occurred in all accessions. Accession ICA-VC3 exhibited lower variation (22.17%), higher average (0.97%) essential oil, and maintained an average abundance of α-humulene greater than 2.6%, which is the amount necessary for phytotherapeutics.

Varronia curassavica tiene propiedades antiinflamatorias debido a los terpenos, α-humuleno y ß-cariofileno, presentes en el aceite esencial. El objetivo de este estudio fue evaluar la influencia de la estacionalidad en el aceite esencial de las accesiones de V. curassavica. Se recolectaron hojas de seis accesiones del Banco de Germoplasma de la Universidad Federal de Minas Gerais durante 12 meses. Se determinaron las correlaciones entre el contenido de aceite esencial y los factores meteorológicos. Se realizó un análisis de cromatografía de gases junto con espectrometría de masas para determinar la composición química del aceite esencial. El contenido y la composición química del aceite varió a lo largo del año. La humedad relativa se correlacionó con las accesiones ICA-VC2 (-0,64) e ICA-VC4 (0,68). En todas las accesiones aparecieron ß-bourboneno, ß-elemeno, espatulenol, germacreno, óxido de cariofileno, α-humuleno y ß-cariofileno. La accesión ICA-VC3 mostró una menor variación (22,17%), un promedio más alto (0,97%) de aceite esencial y mantuvo una abundancia media de α-humuleno superior al 2,6%, que es la cantidad necesaria para los fitoterápicos.

Banco de semillas de relaves mineros como indicador de recuperación de vegetación en Mariana, Brasil / Seed bank of mining tailings as indicator of vegetation regeneration in Mariana, Brazil

Resumen Introducción: El banco de semillas en el suelo es uno de los indicadores ecológicos más importantes para la evaluación y monitoreo de recuperación de ecosistemas degradados. Así mismo, actualmente indicadores ecológicos de restauración son usados en áreas afectadas por la ruptura de la represa de relaves de Fundão en Mariana, Minas Gerais, Brasil. Objetivo: En este estudio se evaluó la variación de la riqueza, composición de especies, densidad y parámetros fitosociológicos del banco de semillas en dos profundidades de relaves mineros en Mariana, municipio de Mariana, Minas Gerais, Brasil. Métodos: Se recolectaron 15 muestras por nivel de profundidad, en la capa superior (Profundidad1, P1 = 0-2.5 cm) y capa inferior (Profundidad2, P2 = 2.5-5.0 cm) del relave de minería para examinar el banco de semillas viable, que luego se colocó en un invernadero para la germinación. Posteriormente se contaron e identificaron semanalmente todos los individuos de cada especie durante un período de seis meses. Resultados: Se demostró que existe un banco de semillas en las capas superficiales de relaves mineros acumulados en las áreas afectadas de Mariana, con una marcada diferencia entre profundidades en términos de riqueza de especies y densidad de individuos. Se observó una mayor riqueza y número de individuos en P1, (1 165 semillas germinadas), pertenecientes a 18 familias y 47 especies, en comparación a P2 (197 individuos), pertenecientes a 12 familias y 23 especies. El banco de semillas de la capa P1 está influenciado por la lluvia de semillas del bosque cercano. Por otro lado, el banco de semillas de P2, puede ser característico de los relaves mineros. Conclusiones: El banco de semillas estudiado puede tener efectos positivos sobre la recuperación en el área de estudio, debido a la alta proporción de especies nativas, pioneras y anemocóricas típicas de etapas iniciales de sucesión secundaria.

Abstract Introduction: The soil seed bank is one of the most important ecological indicators for evaluating and monitoring the resilience of degraded ecosystems. Likewise, ecological restoration indicators are currently used in areas affected by the rupture of the Fundão tailings dam in Mariana, Minas Gerais, Brazil. Objective: To evaluate the seed bank at two depths of areas affected by mining tailings, Mariana municipality, Minas Gerais, Brazil. Methods: 15 samples (40 × 40 cm) were collected per level of depth, in the upper layer (Depth1, P1 = 0-2.5 cm), and lower layer (Depth2, P2 = 2.5-5.0 cm) of the mining tailings to survey the viable seed bank, which was later placed in a greenhouse for germination and seedling identification. The samples were placed in plastic trays to germinate in the nursery, then counted and identified weekly for six months. Results: The results showed that there is a seed bank in the surface layers of accumulated mining tailings in the affected areas of Mariana, with a marked difference between depths in terms of species richness and density of individuals. Higher species richness and number of individuals were observed in P1, (1 165 germinated seeds), belonging to 18 families and 47 species, in comparison to P2 (197 individuals), belonging to 12 families and 23 species. Probably the seed bank of layer P1 is influenced by the rain of seeds from the nearby forest. On the other hand, the P2 seed bank can be characteristic of mining tailings. Conclusions: Seed bank patterns can have positive effects on forest resilience at the local-scale, due to the high proportion of native, pioneer and anemochorical species of early successional stages.

Testing accession genetic composition of a germ-plasm bank for mangabeira (Hancornia speciosa) / Validação da amostragem para composição de um banco de germoplasma de mangabeira (Hancornia speciosa)

The objective of the current study was to measure the genetic variability of natural populations of Hancornia speciosa using RAPD type molecular markers to assay variation in existing sampled genotypes, using morphological variables, and so assess germplasm bank composition. Morphological and chemical characteristics H. speciosa fruits and seeds were evaluated using descriptive statistics and principal components analysis. Cluster analyzes was conducted using Jaccard's similarity index, via the UPGMA hierarchical agglomerative method. Phenotypic variability was found in the two studied populations. However, variability was higher in the São Judas population, where the variables: pulp yield and soluble solids content were higher than those in the Canaã population. High genetic variability was found in both study populations, and between- and within-population morphological and genetic variation was present in the studied populations. The nine primers generated 70 bands, of which 68 were polymorphic, with the primers A-08 and C-04 generating the highest number of polymorphic bands. The two populations differ principally in the pulp ratio and the proportion of total solids in the pulp (°Brix). RAPD markers used gave acceptable results and, to initiate the Federal University of Tocantins Active Mangaba Germplasm Bank, seven genotypes were sampled from the Canaã population and five from the São Judas Tadeu population.

O presente trabalho teve como objetivo mensurar a variabilidade genética de populações naturais de Hancornia speciosa utilizando marcadores moleculares do tipo RAPD para validar a amostragem de genótipos, realizada por meio de variáveis morfológicas, para a composição de um banco de germoplasma. Foram avaliadas características morfológicas e químicas de frutos e sementes de mangaba, utilizando-se estatística descritiva e análise de componentes principais. As análises de agrupamento foram feitas utilizando índice de similaridade de Jaccard, através do método hierárquico aglomerativo UPGMA. Foi observada grande variabilidade fenotípica nas duas populações estudas, porém, essa variabilidade foi maior na população São Judas, onde as variáveis: rendimento de polpa e teor de sólidos solúveis foram maiores que os encontrados na população Canaã. Observou-se uma elevada variabilidade genética nas duas populações estudadas e que existe variabilidade morfológica e genética entre e dentro das populações. As duas populações diferem principalmente em relação ao rendimento de polpa e teor de sólidos solúveis totais (°Brix). Os nove iniciadores que amplificaram geraram 70 bandas, destas, 68 foram polimórficas, onde os primers A-08 e C-04 foram os que geraram maior número de bandas polimórficas. Portanto, os marcadores RAPD utilizados foram eficientes no presente estudo e para comporem o Banco Ativo de Germoplasma de Mangaba da Universidade Federal do Tocantins foram amostrados sete genótipos da população Canaã e cinco da população São Judas Tadeu.

Evaluation of drought tolerance indices for barley landraces under irrigated and dry conditions / Avaliação de índices de tolerância seca para terraços de cevada em condições irrigadas e secas

Barley cultivation for drought areas requires a reliable assessment of drought tolerance variability among the breeding germplasms. Hence, 121 barley landraces, advanced breeding lines, and varieties were evaluated under both moisture non-stress and stress field conditions using a lattice square (11×11) design with two replications for each set of the trials. Twelve drought tolerance indices (SSI, TOL, MP, GMP, STI, YI, YSI, HM, SDI, DI, RDI, and SSPI) were used based on grain yield under normal (Yp) and drought (Ys) conditions. Analysis of variance showed a significant genetic variation among genotypes for all indices except for TOL and SSPI indices. Yp had a very strong association with Ys (r = 0.92**) that indicates high yield potential under non-stress can predict better yield under stress conditions. Yp and Ys were positively and significantly correlated with MP, GMP, STI, YI, HM, and DI indices, whereas they were negatively correlated with SSI and SDI. In principal component analysis (PCA), the first PC explained 64% of total variation with Yp, Ys, MP, GMP, STI, YI, HM, and DI. The second PC explained 35.6% of the total variation and had a positive correlation with SSI, TOL, SDI, and SSPI. It can be concluded that MP, GMP, STI, YI, HM and DI indices with the most positive and significant correlation with the yield at both non-stress and stress environments would be better indices to screen barley genotypes, although none of the indices could undoubtedly identify high yield genotypes under both conditions.

O cultivo de cevada para áreas secas exige uma avaliação confiável da variabilidade da tolerância à seca entre os germoplasmas reprodutores. Assim, 121 linhagens crioulas de cevada (linhas de reprodução avançada e variedades) foram avaliadas em campo sob condições sem estresse e com estresse de umidade do solo, utilizando-se para isso um arranjo experimental de malha quadrada (11×11), com duas repetições para cada conjunto de ensaios. Foram utilizados 12 índices de tolerância à seca (SSI, TOL, MP, GMP, STI, YI, YSI, HM, SDI, DI, RDI e SSPI), com base no rendimento de grãos sob condições normais sem estresse (Yp) e com estresse de seca (Ys). A análise de variância mostrou uma variação genética significativa entre os genótipos para todos os índices, com exceção dos índices TOL e SSPI. Yp teve uma associação muito forte com Ys (r = 0,92**), o que indica que o potencial de alto rendimento sob condições sem estresse pode prever melhor rendimento sob condições de estresse. Yp e Ys foram positivamente e significativamente correlacionados com os índices MP, GMP, STI, YI, HM e DI, enquanto, foram correlacionados negativamente com os índices SSI e SDI. Na análise de componentes principais (PCA), o primeiro PC explicou 64% da variação total com Yp, Ys, MP, GMP, STI, YI, HM e DI. O segundo PC explicou 35,6% da variação total e apresentou correlação positiva com SSI, TOL, SDI e SSPI. Pode-se concluir que, os índices MP, GMP, STI, YI, HM e DI com a correlação mais positiva e significativa com a produção nos ambientes sem estresse e com estresse seriam melhores índices para a seleção de genótipos de cevada, embora nenhum dos índices pudesse concretamente identificar genótipos de alto rendimento sob ambas as condições.

Morphoagronomic characterization of Lantana camara L. germplasm / Caracterização morfoagronômica de germoplasma de Lantana camara L

The medicinal and aromatic species Lantana camara is a bush that receives a lot of interest regarding ornamental use. However, due to its condition of invasive plant in natural environments, it suffers constant eradication attempts, which causes genetic erosion of the species. To work around this problem, a sample of the genetic variability of L. camara was saved in the Active Germplasm Bank of medicinal and aromatic plants of the Federal University of Sergipe (UFS). This study aimed to evaluate morphoagronomically 22 accessions of L. camara, collected in 15 municipalities in the state of Sergipe. To carry out morphoagronomic characterization, morphological and agronomic traits were analyzed. Phenotypic variability among the accessions of the L. camara collection for all the analyzed morphological quantitative and agronomic characteristics was observed. The means ranged from 4.91 to 6.90 cm for leaf length; from 2.81 to 5.03 cm for leaf width; from 1.32 to 1.87 for the leaf length/width ratio; from 9.59 to 22.98 mm2 for leaf area; from 99.00 to 215.00 cm for crown diameter; from 85.67 to 214.33 for plant height; and from 1.08 to 2.43 cm for stem diameter. Most accessions presented erect form. The mean number of flowers per inflorescence varied from 12 to 38 flowers. For the agronomic traits, we observed that the dry mass ranged from 49.86 to 649.04 g.plant-1. The mean content of essential oil ranged from 0.13 to 0.26% and yield between 0.10 and 1.55 mL.plant-1. The most divergent phenotypic accessions were LAC-001 (São Cristóvão) and LAC-038 (Moita Bonita) and the ones with the lowest divergence were LAC-004 (Itaporanga D'ajuda) and LAC-019 (Siriri). Thus, it was observed that the variables were efficient to differentiate the accessions and suggest the existence of genetic variability among them.

A espécie aromática e medicinal Lantana camara, é um arbusto muito usado para ornamentação. Devido à sua condição de planta invasora em ambientes naturais, sofre com tentativas de erradicação constantes, o que ocasiona erosão genética da espécie. Para contornar essa problemática, uma amostra da variabilidade genética da L. camara está sendo conservada no Banco Ativo de Germoplasma (BAG) de Plantas Medicinais e Aromáticas da Universidade Federal de Sergipe (UFS). Assim, objetivou-se com o presente trabalho avaliar morfoagronomicamente 22 acessos de L. camara, coletados em 15 municípios do estado de Sergipe. Para caracterização morfoagronômica, variáveis morfológicas e agronômicas foram analisadas. Observou-se variabilidade fenotípica entre os acessos da coleção de L. camara para a maioria das características morfológicas quantitivas e agronômicas. A média para comprimento de folha variou de 4,91 e 6,90 cm; largura de folha de 2,81 a 5,03 cm; relação comprimento/largura de 1,32 a 1,87; área folia de 9,59 a 22,98 mm²; diâmetro da copa de 99, 00 a 215,00 cm; altura de planta de 85,67 a 214,33 cm; diâmetro do caule de 1,08 a 2,43 cm; A maioria dos acessos apresentou porte ereto. O número médio de flores por inflorescências variou de 12 a 38. Para as características agronômicas observou-se que a massa seca variou de 49,86 a 649,04 g.planta-¹. A média para teor de óleo essencial variou de 0,13 a 0,26% e o rendimento entre 0,10 a 1,55 mL.planta-¹. Os acessos mais divergentes fenotipicamente foram LAC-001 (São Cristóvão) e LAC-038 (Moita Bonita) e os que apresentaram a menor divergência foram LAC-004 (Itaporanga D'ajuda) e LAC-019 (Siriri). Dessa forma, nota-se que as variáveis foram eficientes para diferenciar os acessos e sugerem a existência de variabilidade genética entre eles.

Vegetation and seed bank of an open-scrub bush restinga formation in the Southeastern coast of Brazil / Vegetación y banco de semillas en una formación de matorral abierto de restinga en el sureste de Brasil

Introduction: Restingas are coastal plain ecosystems located along Eastern Brazil, corresponding to about 5 000 km.The restinga vegetation is associated with the Atlantic rainforest biome and comprises four distinct main formation zones: coastal grasslands, shrublands, open-forests and marsh zones. Especially due to coastal urbanization, this is a threatened ecosystem that, through its different shrub formations, exhibits a unique mosaic as a result of the vegetation distribution in nuclei of different covering, physiognomy and floristic composition. Objective: We aimed to characterize the above and belowground composition of a conserved, non-flooded, open-scrub, nuclei (patches of bushes) formation of restinga in Linhares, ES, southeastern Brazil. Methods: The vegetation survey was conducted using the line intercept method. Diameter and height of the first six nuclei were measured in five transects separated by 50 m, totaling 30 nuclei up to 350 m away from the shore line. The phytosociology and Shannon Index of the aboveground vegetation community were calculated. In the same 30 nuclei, leaf litter and topsoil layer (15 x 15 x 10 cm) samples were collected to survey the viable seed bank, which was later placed in a greenhouse for germination and seedling identification. The Sørensen Similarity index (SSi) was used to compare the floristic composition between the leaf litter and topsoil layer seed banks. Nuclei volume and number of species were calculated as well. Results: In the aboveground vegetation, 54 plant species belonging to 32 families were identified, totaling 1 098 individuals. The nuclei showed a diversity (H') of 3.08 nats, and an average diameter of 11.5 m (s = 9.1), area of 526.4 m2 (s = 1 081.7), and height of 2.9 m (s = 1.1). Davilla flexuosa, followed by Smilax rufescens, presented the highest IVI (Importance Value Index). A total of 1 839 seedlings from 32 species and 19 families were identified in the seed bank. Enydra sessilis (Asteraceae) had the highest seed density (544), while the family with highest species richness was Cyperaceae. A low similarity between the vegetation surveyed and the seed bank composition was found (only 5 species in common, SSi = 0.10). Conclusions: The results indicate that a post-disturbance early community, established from the seed bank, would have a substantially different species composition, but with other potential species to restore vegetation over the long-term succession.

Introducción: Las restingas son ecosistemas llanos costeros ubicados a lo largo del este de Brasil, que corresponden a unos 5 000 km de la costa atlántica brasileña. La vegetación de restinga está asociada con el bioma de la selva tropical atlántica y comprende cuatro zonas de formación principales: praderas costeras, matorrales, bosques abiertos y zonas pantanosas. Especialmente debido a la urbanización costera, este es un ecosistema amenazado, que, a través de sus formaciones arbustivas, exhibe un mosaico único, como resultado de la distribución de la vegetación en núcleos de diferentes coberturas, fisonomía y composición florística. Objetivo: Caracterizar la composición florística superficial y subterránea de una formación conservada, no inundada, de núcleos de matorral abierto de restinga en Linhares, ES, costa del sureste de Brasil. Métodos: La vegetación se muestreó utilizando el método de la línea de intercepción. El diámetro y la altura de los primeros seis núcleos se midieron en cinco transectos instalados cada 50 m, con un total de 30 núcleos distantes hasta 350 m de la línea de costa. Se muestreó la comunidad de vegetación y se calculó su fitosociología e índice de Shannon. En los mismos 30 núcleos, se recogió la hojarasca más la capa superior del suelo (15 x 15 x 10 cm) para examinar el banco de semillas viable, que luego se colocó en un invernadero para germinar e identificar las plántulas. El índice de similitud de Sørensen se usó para comparar la composición florística entre la hojarasca y el banco de semillas de la capa superficial del suelo y también se calculó la regresión entre el volumen del núcleo y el número de especies. Resultados: En la vegetación superficial se identificaron 54 especies de plantas pertenecientes a 32 familias, con un total de 1 098 plantas. Los núcleos registraron una diversidad (H') de 3.08 nats, y un diámetro promedio de 11.5 m (s = 9.1), área de 526.4 m² (s = 1 081.7) y altura de 2.9 m (s = 1.1). Davilla flexuosa, seguida de Smilax rufescens, presentó el VI (Valor de Importancia) más alto. Se identificaron un total de 1 839 plántulas de 32 especies y 19 familias en el banco de semillas. Enydra sessilis (Asteraceae) tuvo la mayor densidad de semillas viables (544), pero la familia con mayor riqueza de especies fue Cyperaceae. Se encontró una baja similitud entre la vegetación y la composición del banco de semillas (solo 5 especies en común, índice de Sørensen = 0.10). Conclusiones: Los resultados indican que una comunidad recién establecida después de una alteración podría tener una composición de especies sustancialmente diferente, pero con otras especies potenciales para restaurar la vegetación a largo plazo.

Serological and Molecular Detection of Latent Viruses in the Apple Germplasm Bank of Santa Catarina

Abstract The Apple Germplasm Bank (AGB) of Santa Catarina Agricultural Research and Rural Extension Company - Epagri, AGB-Epagri, is the largest of the genus Malus in Brazil. Twenty-eight main accessions of this bank were virus screened through DAS-ELISA, RT-PCR and IC-RT-PCR during two consecutive reproductive cycles, and each accession showed latent mixed infection by at least two species, among ASGV, ASPV and ACLSV. The combined use of diagnostic methods helped overcome inconsistencies commonly found in apple virus detection and was shown essential for the AGB-Epagri can be safely used as a source of genetic variability and for the exchange of virus-free propagative material.

Genetic characterization of silkworm (Bombyx mori L. ) strains (Lepidoptera: Bombicidae) with different geographical originon the basis of isozyme markers

The aim of the present study was to assess genetics variations within and among strains with different geographical origin, belonging to Bulgarian germplasm bank of mulberry silkworm (Bombyx moriL.)and to establish their relationships using isoenzyme markers. Polyacrilamide gel electrophoresis (PAGE) was used to study the isoenzymes of nonspecific esterases (EST), malate dehydrogenase (MDH) and acid phosphatase (ACP) from haemolymph, phosphoglucomutase (PGM) and hexokinase (HK) from silk glands and alkaline phosphatase (ALP) from midgut of mulberry silkworm (Bombyx moriL.). Variability was evident in all of these enzyme systems among twelve strains from Bulgarian germplasm resources of B. mori.Total of nine lociwere detected. All of them (100%) were polymorphic. “Null” alleles in four lociwere determined. Intra-and inter-strain polymorphism was obtained. The degree of polymorphism ranged from 0% to 77.80%. Low levels of observed heterozygosity in comparison with the expected one have been calculated in almost all of strainsas well as deviations from Hardy-Weinberg equilibrium in almost all analyzed loci, resultingof excess of homozygotes. The value of FSTwas 0.4903. The dendrogram constructed with the values of genetic distance manifests that Romanian strain Cislau Tokay is formed one main clade while the rest strains studied (from Bulgaria, Japan, China, Vietnam, Spain, Syria and Egypt) are formed the other clade withsubclades. The genetic data of the tested strains from different geographical regions, would be used for identifying suitable parents for breeding programs with a view to yield improvement in this species with economic significance.

Morphoagronomic characterization of sweet potato accessions from the germplasm bank of Embrapa hortaliças / Caracterização morfológica de acessos de batata-doce mantidos no banco de germoplasma da Embrapa Hortaliças

Studies on the determination of genetic divergence among genotypes are important tools in breeding programs, contributing to the identification of parents with considerable productive potential. However, little is known about the combinatorial capacity of sweet potato (Ipomoea batatas) accessions and its adaptation to the different regions of Brazil. The objective of this study was to evaluate the morpho-agronomic traits from 102 sweet potato accessions from the Germplasm Bank of Embrapa Hortaliças. The experiment was laid out as an augmented block design comprised of 102 treatments. Nineteen above ground traits were measured using descriptors for the respective parts. Estimated values of broad sense heritability were high for the traits mean branch length (95.75%), immature leaf color (85.06%), and predominant branch color (90.57%). Coefficients of environmental variation were below 30.00% for all variables, except for branch weight (51.62%). The 102 clones analyzed presented broad genetic variability for the different traits evaluated, especially for branch weight, and branch length, and mature leaf color.

Estudos de determinação de divergência genética entre genótipos são ferramentas de grande importância em programas de melhoramento, auxiliando na identificação de genitores com considerável potencial produtivo. No entanto, pouco ainda se sabe sobre a capacidade combinatória de acessos de batata-doce (Ipomoea batatas) e sobre a adaptação a diferentes regiões do Brasil. O objetivo deste trabalho foi avaliar características agronômicas de 102 acessos de batata-doce mantidos no Banco de Germoplasma da Embrapa Hortaliças. O experimento foi instalado utilizando o delineamento em blocos aumentados, com 102 tratamentos. Foram mensuradas 19 características da parte aérea utilizando-se descritores das respectivas partes. Os valores das estimativas de herdabilidade no sentido amplo foram altos para as características comprimento médio das ramas (95,75%), cor da folha imatura (85,06%) e cor predominante da rama (90,57%). Os coeficientes de variação foram inferiores a 30 % para todas as variáveis, exceto para peso das ramas (51.62%). Os 102 clones analisados apresentaram ampla variabilidade genética para as diferentes características avaliadas, principalmente para peso das ramas, comprimento das ramas e cor da folha madura

Soil attributes and weed seedbank spatial correlation / Correlação espacial entre atributos físicos e químicos do solo e o banco de sementes de plantas infestantes

The crop yield potential is affected by the crop-weed competition and their control create a dependence on herbicide use who brings, as consequence, soil impacts. Knowing the weed's spatial distribution on the field is a feasible alternative for improving the crop yield. The goal of this paper is the identification of the spatial variability on physical and chemical attributes of soil as well as the weed's seedbank so that, when correlated, may find standards to help on field management. The experiment was conducted on Uberlandia Federal University premises at soybean no-till area. Using georeferenced soil samples, were analyzed the physical and chemical attributes as well as the weed's seedbank. The weed population on controlled environment was quantify, sorting out broadleaf and grassy weeds species. The obtained data were analyzed by descriptive statistic and geostatistics for a semivariogram modeling, interpolation by the kriging methodology and the spatial variability maps achievement. The average value, coefficient of variation (CV%), asymmetry, kurtosis coefficient and the significant linear correlations interfered on data spatial variability which we concluded by the spatial dependences on the attributes that had a linear correlation between them. The semivariograms presented varied range between 202 to 752 meters. Using the maps, verified two different regions for the broadleaf and grassy weeds seedbank. For both situations there was influence by the soil attributes on infestation level, which makes it possible to target the herbicide management reducing costs and the environmental impact. From the analyzed data we conclude that there is a spatial dependence for the physical and chemical soil attributes and their spatial distribution explains the weed seedbank spatial variability.

O potencial produtivo das culturas é afetado pela competição por plantas infestantes e o seu controle cria dependência no uso de herbicidas, com consequente impacto ao solo. Conhecer o comportamento espacial das espécies infestantes é alternativa viável no aumento do lucro das lavouras. O presente trabalho teve por objetivo identificar o comportamento espacial nos atributos físicos e químicos do solo e no banco de sementes de plantas infestantes, de maneira que, ao correlacioná-los possa-se encontrar padrões que auxiliem no manejo das áreas agrícolas. O estudo foi realizado em área pertencente à Universidade Federal de Uberlândia-MG em área cultivada com soja em plantio direto. A partir de amostragens georreferenciadas foi realizada avaliação química e física do solo e determinação do banco de sementes de plantas infestantes. Foi mensurado o número de plantas infestantes em ambiente controlado, separando as espécies germinadas em Folha Estreita e Folha Larga. Os dados foram avaliados pela estatística descritiva e geoestatística, para ajuste de semivariogramas, interpolação por krigagem e obtenção de mapas de distribuição espacial. Os valores de média, CV%, assimetria, curtose, e as correlações lineares significativas inferiram no comportamento espacial dos dados, comportamento verificado pela dependência espacial observada para os atributos com correlação linear significativa entre eles. Os semivariogramas apresentaram alcance variando entre 202 m e 752 m. A partir dos mapas verifica-se duas regiões distintas para o banco de plantas infestantes de folha estreita e larga. Para ambas situações houve contribuição dos atributos do solo nos níveis de infestação, o que possibilita o direcionamento no ajuste de doses herbicidas para redução de custos e impacto ambiental. A partir dos dados conclui-se que há comportamento espacial para atributos químicos e físicos de solo, e a sua distribuição espacial explica o comportamento espacial do banco de sementes de plantas infestantes.

Population Structure and Genetic Diversity of Sweet Cassava Accessions from the Midwestern, Southeastern and Southern Regions of Brazil

Abstract The objective of this work was to screen sweet cassava accessions collected in smallholding areas in the Midwestern, Southeastern and Southern regions of Brazil, using 15 SSR molecular markers, to determine population structure and genetic diversity. Polymorphism was detected in every loci analyzed, with mean of 6.33 alleles per locus, and mean polymorphism information content (PIC) of 0.6057, pointing out that the primers were highly informative. The observed heterozygosity ranged from 0.0709 (SSRY 101) to 0.9398 (GA 12), with a mean of 0.6511, and mean genetic diversity of 0.6578, ranging from 0.3592 (GA 136) to 0.8116 (SSRY 21). The most dissimilar combinations observed were BGM526PR-BGM596MS, BGM526PR-BGM622MS and BGM526PR-BGM629MS. The traditional cassava cultivars assessed were divided into four distinct groups: two with cultivars from the South, one from the Southeast and one from the Midwestern region of Brazil. The variances among and within groups determined by the analysis of molecular variance were 44 and 56%, respectively. The PhiPT parameter (analogue to Fst) of 0.44 indicates high differentiation among groups. Broad genetic diversity was found among the traditional sweet cassava cultivars assessed, and the most divergent groups were formed by cultivars from the South and the Midwestern regions of Brazil.

Ornamental potential of sweet potato accessions / Potencial ornamental de acessos de batata-doce

Sweet potato [Ipomoea batatas (L.) Lam.] is a multipurpose plant due to the different uses for its roots, leaves, and branches. The objective of this study was to evaluate the ornamental potential of sweet potato accessions from the Germplasm Bank of Embrapa Hortaliças, Brasilia, DF, Brazil. The morphological characterization and evaluation of the ornamental potential used five accessions with distinct leaf shape (CNPH 980, CNPH 1205, CNPH 895, CNPH 796, CNPH 1284) and 12 qualitative and quantitative descriptors [plant type (PT), leaf lobe type (LLT), immature leaf color (ILC), leaf lobe number (LLN), branch color (BC), shape of central leaf lobe (SCLL), petiole pigmentation (PP), mature leaf size (MLS), mature leaf color (MLC), leaf shape (LS), branch yield (BY), and root yield (RY)]. In the evaluation of the ornamental potential, each criterion was scored from 10 (minimum) to 100 (maximum). Leaf lobe number was the trait that pleased the evaluators the most, and the greater the number of lobes, the greater was the ornamental potential. CNPH 980, CNPH 1205, and CNPH 1284 stood out for this trait. CNPH 1284 (almost divided leaf type) had the greatest score and was considered, by the evaluators, as the accession with the most harmonious aesthetics, indicating a great ornamental potential for the consumer market. All accessions studied presented considerable ornamental potential and could be used in floral arrangements or garden beds.

A batata-doce [Ipomoea batatas (L.) Lam.] é uma planta com diferentes aptidões de uso das suas raízes, folhas e hastes. O objetivo deste trabalho foi avaliar o potencial ornamental de acessos de batata-doce oriundas do banco de germoplasma mantidos na Embrapa Hortaliças, Brasília, DF, Brasil. Para a caracterização morfológica e avaliação do potencial ornamental, foram escolhidos cinco acessos com formatos de folhas diferentes (CNPH 980, CNPH 1205, CNPH 895, CNPH 796, CNPH 1284) e utilizados doze descritores qualitativos e quantitativos [tipo de planta (TP), tipo de lóbulo da folha (TLF), cor da folha imatura (CFI), número de lóbulos por folha (NLF), cor das ramas (CR), formato do lóbulo central (FLC), pigmento no pecíolo (PP), tamanho da folha madura (TFM), cor da folha madura (CFM), formato da folha (FF), produção de ramas (BY) e produção de raízes (RY)]. Na avaliação do potencial ornamental, cada critério foi pontuado por meio de notas variando de 10 (mínimo) a 100 (máximo). A característica número de lóbulos da folha foi a que mais agradou os avaliadores. Observou-se que quanto mais lóbulos, maior o potencial ornamental, sendo que os acessos CNPH 980, CNPH 1205 e CNPH 1284 se destacaram para essa característica. CNPH 1284, com folhas no formato quase dividido, obteve a maior nota e foi considerado como o acesso com a estética mais harmoniosa, indicando grande potencial ornamental para o mercado consumidor, na opinião dos avaliadores. Os cinco acessos estudados apresentaram considerável potencial ornamental, podendo ser usados como forragem, complementos para arranjos florais ou como jardineiras.

Germination and seed conservation of a pioneer species, Tecoma stans (Bignoniaceae), from tropical dry forest of Colombia / Germinación y conservación de semillas de la especie pionera, Tecoma stans (Bignoniaceae), del bosque seco tropical de Colombia

Abstract Seed germination and seed longevity under different environmental conditions are fundamental to understand the ecological dynamics of a species, since they are decisive for its success within the ecosystem. Taking this into account, seed germination and seed storage behavior of a pioneer species of tropical dry forest (Tecoma stans) were studied in the laboratory, to establish the effect of different environmental conditions on a local tree population. Two seed lots collected in July 2011, from Cali (Colombia), were evaluated under three alternating temperatures (20/30, 20/25, 25/30 ºC; 16/8 h) and four light qualities (12-hour white light photoperiod, darkness, and 15 minutes of red light -R and far red light -FR). Final germination was recorded for all treatments; for white light treatment the daily germination was recorded to calculate mean germination rate, mean germination time, and two synchronization indices. To assess the effect of light quality on physiological variables, a destructive germination test was carried out. For this test, another seed lot was evaluated under the same light conditions using an alternating temperature of 20/30 °C - 16/8 h, recording germination during six days for every treatment. In addition, seeds were stored at two different moisture contents (7.7, 4.1 %) and three storage temperatures (20, 5, -20 ºC), during two time periods (one and three months); a seed germination test was conducted for each treatment. Four replicates of 35 seeds per treatment were used for all experiments. Germination was high (GP > 90 %) with all alternating temperatures under white light, whereas under R, FR, and darkness germination was evenly successful at low temperatures, but at higher temperature, half of the seeds entered into secondary dormancy (GP= 45-65 %). However, mean germination rate and synchronization under R and FR decreased significantly in comparison to white light treatment and, consequently, mean germination time increased. Seed storage behavior of this species is orthodox due to the high germination (GP > 90 %) obtained under all treatments. In conclusion, T. stans seeds have a negative germination response at high incubation temperatures in the absence of white light, entering into a secondary dormancy. In contrast, an environment with a lower temperature and without white light delays the germination, but at the end seeds are able to reach the same germination values. This seed dependence on incident light in limiting conditions suggests a physiological mechanism on the seed tissues of this species, probably mediated by phytochromes. Finally, the orthodox seed storage behavior of T. stans is a reason to include this species in ex situ seed conservation programs for restoration and recovery of the tropical dry forest; however, long-term studies should be conducted in order to evaluate the maintenance of this characteristic throughout longer periods of time. Rev. Biol. Trop. 66(2): 918936. Epub 2018 June 01.

Resumen La germinación y la longevidad de las semillas de una especie bajo diferentes condiciones ambientales son fundamentales para las dinámicas ecológicas de una especie, debido a que son decisivas en el éxito de la misma en un ecosistema. Teniendo en cuenta esto, se estudió la germinación y el comportamiento en el almacenamiento de las semillas de una especie pionera de bosque seco tropical (Tecoma stans) a nivel de laboratorio, para establecer el efecto de diferentes condiciones ambientales en una población local de árboles. Dos lotes de semillas recolectados en julio 2011, de Cali (Colombia), se evaluaron a tres temperaturas alternadas (20 / 30, 20 / 25, 25 / 30 °C; 16 / 8 h) y cuatro calidades de luz (fotoperiodo de 12 horas de luz blanca, oscuridad, y 15 minutos de luz roja -R y roja lejana -RL). Se registró la germinación final para todos los tratamientos; para el tratamiento de luz blanca se registró la germinación diaria para calcular la tasa media de germinación, el tiempo medio de germinación y dos índices de sincronización. Para evaluar el efecto de la calidad de luz sobre las variables fisiológicas, se realizó una prueba de germinación destructiva. Para esta prueba, otro lote de semillas fue puesto a las mismas condiciones de luz usando una temperatura alternada de 20 / 30 °C - 16 / 8 h, registrando la germinación durante seis días para cada tratamiento. Además, se almacenaron semillas a dos contenidos de humedad (7.7, 4.1 %) y a tres temperaturas de almacenamiento (20, 5, -20 °C), durante dos periodos de tiempo (uno y tres meses); se realizó una prueba de germinación a cada tratamiento. Cuatro repeticiones de 35 semillas por cada tratamiento se usaron en cada experimento. La germinación fue alta (PG > 90 %) en todas las temperaturas alternadas con luz blanca, mientras que en los tratamientos de luz R, RL y en oscuridad, la germinación fue igualmente exitosa a bajas temperaturas, pero a temperaturas más altas la mitad de las semillas entraron en latencia secundaria (PG= 45-65 %). Sin embargo, la tasa media de germinación y la sincronización en R y RL disminuyeron significativamente en comparación con el tratamiento de luz blanca y consecuentemente el tiempo medio de germinación aumentó. El comportamiento de las semillas de T. stans en el almacenamiento es ortodoxo debido a la alta germinación obtenida (PG > 90 %) en todos los tratamientos. En conclusión, las semillas de T. stans tienen una respuesta germinativa negativa a temperaturas de incubación alta en ausencia de luz blanca, donde entran a latencia secundaria. En contraste, un ambiente con baja temperatura y sin luz blanca retrasa la germinación, pero al final las semillas son capaces de alcanzar los mismos valores de germinación. Esta dependencia de las semillas a la luz incidente en condiciones limitantes sugiere la presencia de un mecanismo fisiológico en los tejidos de esta especie, probablemente mediado por fitocromos. Finalmente, el comportamiento ortodoxo de las semillas de T. stans en el almacenamiento abre la posibilidad de incluirla en programas de conservación ex situ para la restauración y recuperación del bosque seco tropical; no obstante, se deben llevarse a cabo pruebas más largas para evaluar el mantenimiento de esta característica por periodos de tiempo más largos.

Methodological approaches to assess passion fruit resistance (Passiflora spp. ) to passionfruit woodiness disease / Aspectos metodológicos para avaliação da resistência do maracujazeiro (Passiflora spp. ) à virose do endurecimento dos frutos

The passion fruit woodiness disease, induced by Cowpea aphid borne mosaic virus (CABMV), is considered the most economically important factor limiting passion fruit production in many countries. This study aimed to assess the progression of symptoms caused by CABMV in different Passiflora species. Eighty genotypes belonging 12 species were evaluated in experiments carried out in a completely randomized block design with treatments arranged in a factorial scheme (80 genotypes x 7 evaluation intervals) considering each inoculated plant as a repetition. The disease severity was estimated by the disease index (DI). The evaluations were performed at 20, 27, 34, 41, 48, 55 and 62 days after inoculation (DAI). The average DI values were used to describe the disease progress at each evaluation interval. The shortest time from evaluation to stabilization of CABMV progress was considered to cluster the genotypes by the Scott- Knott test (p0.05) and to classify the genotypes as resistant (R), moderately resistant (MR), moderately susceptible (MS), susceptible (S) or highly susceptible (HS). The mean severity gradually increased in the intervals from 20 to 55 DAI and reached a maximum at 62 DAI. The five classes (R, MR, MS, S and HS) contained about 19, 24, 36, 10 and 11% of the germplasm accessions, respectively. The disease temporal progress was quite variable within and among groups, although no difference in DI was observed in the genotypes after 55 DAI, indicating genotype symptom stabilization at this time, regardless of the genotype resistance level.

O endurecimento dos frutos causada pelo Cowpea aphid borne mosaic virus (CABMV) é considerada a doença mais importante economicamente limitando a produção de maracujazeiro em vários países. O objetivo deste trabalho foi avaliar o progresso dos sintomas causados pelo CABMV em espécies de Passiflora. O estudo foi realizado em delineamento em blocos casualizados, em esquema fatorial (80 genótipos x 7 períodos de avaliação) considerando cada planta como uma repetição, utilizando 80 genótipos pertencente a 12 espécies de maracujazeiro. A severidade foi estimada por meio do índice de doença (ID). As avaliações foram realizadas 20, 27, 34, 41, 48, 55 e 62 dias após a inoculação (DAI). As médias do ID foram utilizadas para verificar a evolução da doença em cada período de avaliação. O período mínimo para estabilização do progresso do CABMV foi utilizado para agrupar os genótipos pelo teste Scott-Knott (p0,05), bem como para classificar os genótipos em resistente (R), moderadamente resistente (MR), moderadamente suscetível (MS), suscetível (S), e altamente suscetível (AS). A severidade média da doença aumentou gradativamente nos intervalos de 20 a 55 DAI e atingiu seu máximo aos 62 DAI. Cerca de 19, 24, 36, 10 e 11% do germoplasma avaliado foi classificado como R, MR, MS, S e AS, respectivamente. O progresso temporal da doença foi bastante variável dentro e entre os grupos, embora não tenha sido observada diferença no ID dos genótipos a partir de 55 DAI, indicando a estabilização dos sintomas a partir deste período, independentemente do nível de resistência do genótipo.

Formación del banco de semillas durante la revegetación temprana de áreas afectadas por la minería en un bosque pluvial tropical del Chocó, Colombia / Soil seed bank formation during early revegetation of areas affected by mining in a tropical rain forest of Chocó, Colombia

ResumenLa minería es una de las principales actividades económicas en muchas regiones tropicales y también es la causa de la devastación de amplias superficies de bosques tropicales naturales. El conocimiento del potencial regenerativo de las áreas alteradas por minería es vital para la restauración ecológica de estas áreas críticas. El objetivo del presente trabajo fue evaluar el efecto de la edad de abandono de las minas y su distancia al bosque adyacente sobre la formación del banco de semillas del suelo en minas abandonadas en el San Juan, Chocó, Colombia. Para ello, se determinó la abundancia y composición de especies del banco de semillas, así como la dinámica de la lluvia de semillas, en minas de distinta edad (6 y 15 años), tras el cese de la actividad minera, y distancia a la matriz del bosque adyacente (50 y 100 m). La lluvia de semillas estuvo compuesta por cinco especies de plantas, todas de dispersión anemócora, y fue mayor en la mina de 6 años que en la de 15. No hubo diferencias significativas en la cantidad de semillas recolectadas a 50 m y 100 m de distancia del bosque adyacente. El banco de semillas estuvo representado por ocho especies: dos de dispersión anemócora (comunes a la lluvia de semillas) y el resto de dispersión zoócora. La abundancia de semillas en el suelo no varió con la edad de la mina, pero fue mayor a distancias próximas al bosque que alejadas de este. Durante la regeneración temprana, la formación del banco de semillas en el seno de las minas parece estar relacionada con la cercanía a otras áreas alteradas más que con su proximidad al bosque adyacente o la edad de las minas. Al respecto, el establecimiento de perchas artificiales o conservación de árboles remanentes en el seno de las minas podrían promover la entrada de semillas dispersadas por aves. No obstante, dado que el banco de semillas del suelo puede verse afectado por la alta precipitación de la zona, se recomienda promover estudios que valoren medidas encaminadas a favorecer la formación del banco de semillas del suelo de las minas en ambientes de alta pluviosidad como en la región del Chocó.

Abstract:Mining is one of the main economic activities in many tropical regions and is the cause of devastation of large areas of natural tropical forests. The knowledge of the regenerative potential of mining disturbed areas provides valuable information for their ecological restoration. The aim of this study was to evaluate the effect of age of abandonment of mines and their distance from the adjacent forest, on the formation of soil seed bank in abandoned mines in the San Juan, Chocó, Colombia. To do this, we determined the abundance and species composition of the soil seed bank, and the dynamics of seed rain in mines of different cessation period of mining activity (6 and 15 years), and at different distances from the adjacent forest matrix (50 and 100 m). Seed rain was composed by five species of plants with anemocorous dispersion, and was more abundant in the mine of 6 years than in the mine of 15 years. There were no significant differences in the number of seeds collected at 50 m and 100 m from the adjacent forest. The soil seed bank was represented by eight species: two with anemocorous dispersion (common among the seed rain species) and the rest with zoochorous dispersion. The abundance of seeds in the soil did not vary with the age of the mine, but was higher at close distances to the forest edge than far away. During the early revegetation, the formation of the soil seed bank in the mines seems to be related to their proximity to other disturbed areas, rather than their proximity to the adjacent forest or the cessation activity period of mines. Therefore, the establishment of artificial perches or the maintenance of isolated trees in the abandoned mines could favour the arrival of bird-dispersed seeds at mines. However, since the soil seed bank can be significantly affected by the high rainfall in the study area, more studies are needed to evaluate management actions to encourage soil seed bank formation in mines of high-rainfall environments in the Chocó region. Rev. Biol. Trop. 65 (1): 393-404. Epub 2017 March 01.

Diaspore bank of aquatic macrophytes maintaining species diversity in a Neotropical pond / Banco de diásporos de macrófitas aquáticas para a manutenção da diversidade das espécies em uma lagoa Neotropical

The diaspore bank is an important component of biological diversity acting mainly as storage and source of diaspores, which also indicate dynamics and patterns of maintenance of plant diversity. We tested the hypothesis that the diaspore bank would be the responsible factor for the maintenance of the aquatic plant species, used two techniques to evaluate the diaspore bank: seedling emergence and direct counting of field samples. Density and richness of the diaspore bank were correlated with plant cover of the aquatic macrophyte communities and also with the euphotic zone radiation in different phases of the hydrological cycle. The diaspore bank is a key factor in maintenance of aquatic macrophyte assemblages in this pond. Nymphaea amazonum was one of the dominant species in the pond and presented temporally peaks of plant cover. Furthermore, depth allowed induction of germination of stored diaspores. Therefore, the diaspore bank may predict which species colonizes a site when environmental characteristics are favorable and allows inferring which processes are linked to changes in structure of aquatic macrophyte assemblages. These mechanisms are the means for recovery of macrophyte species under natural disturbances, represented by water level oscillations in floodplains.

O banco de diásporos é um componente importante da diversidade biológica atuando principalmente como armazenamento e fonte de diásporos, que também indicam a dinâmica e os padrões de manutenção da diversidade vegetal. Testamos a hipótese de que o banco de diásporos seria o fator responsável pela manutenção das espécies de plantas aquáticas, utilizando duas técnicas para avaliar o banco diásporo: emergência das plântulas e contagem direta de amostras de campo. Densidade e riqueza do banco de diásporos foram correlacionadas com cobertura vegetal das comunidades de macrófitas aquáticas e também com a radiação da zona eufótica em diferentes fases do ciclo hidrológico. O banco de diásporos é um fator chave na manutenção das assembleias de macrófitas aquáticas nesta lagoa. Nymphaea amazonum foi uma das espécies dominantes na lagoa temporalmente, apresentou picos de cobertura vegetal. Além disso, a profundidade permitiu a indução da germinação de diásporos armazenados. Portanto, o banco de diásporo é um preditor de quais espécies colonizarão um local quando as características ambientais são favoráveis e permite inferir que os processos estão ligados a mudanças na estrutura das assembleias de macrófitas aquáticas. Estes mecanismos são os meios para a recuperação de espécies de macrófitas sob as perturbações naturais, representados por oscilações do nível de água nas planícies aluviais.