RESUMO Hymenaea courbaril L. é uma importante espécie Neotropical, que aparece com baixa densidade populacional, restrita a fragmentos de florestas semidecíduas, com baixa mortalidade e baixo recrutamento. Assim, algumas questões orientaram os objetivos deste trabalho, incluindo a capacidade de sementes armazenadas para formar mudas normais. Sementes coletadas de dez plantas-mãe na região do cerrado brasileiro e armazenadas durante três anos foram mecanicamente escarificadas, semeadas e analisadas durante 43 dias. Foi observada variabilidade intraespecífica para teor de água, biometria das sementes e para o processo de emergência. A emergência das plântulas variou de 19 a 92%. Nove fases de desenvolvimento foram observadas. Cerca de 91% das mudas alcançou sua autotrofia e isso representa o sucesso da amostra. O restante das plântulas apresentou morfologia atípica. Isto significa que é possível armazenar as sementes com o propósito de obter plântulas para cultivo ex situ. O grande consumo das reservas cotiledonares ocorreu no período que marca o alinhamento de cotilédones com o hipocótilo, durante as fases 1 a 4. Para esta espécie, se as sementes forem escarificadas, os primeiros 40 dias após a semeadura são essenciais para o estabelecimento das plântulas. Após esse tempo, os cotilédones caem e esse sinal é um bom ponto de referência para projetos de restauração, pois ele indica que a planta jovem está autônoma.

ABSTRACT Hymenaea courbaril L. is an important Neotropical species, with low population density, restricted to fragments of semideciduous forests, with low mortality and low recruitment. Thus, some questions guided the goals of this paper including the capacity of stored seeds to form normal seedlings. Seeds collected from ten mother plants in the Brazilian Cerrado region and stored during three years were mechanically scarified, sown and analyzed during 43 days. Intraspecific variability was observed for water content, seed biometry, and emergence process. The seedling emergence varied from 19 to 92%. Nine phases of development were observed. About 91% of the seedlings reached their complete autotrophy and this represents the success of the sample; the rest of the seedlings presented atypical morphology. This means that it is possible to store the seeds with the purpose of obtaining seedlings for ex situ cultivation. The great consumption of the cotyledon reserves occurred in the period that marks the alignment of cotyledons with hypocotyls (phases 1 to 4). For this species, if the seeds are scarified, the first 40 days after sowing are essential for the seedling establishment. After this time, the cotyledons fall signing a good point of reference for restoration projects because it indicates that the young plant is autonomous.

Ao se analisar a trajetória do setor de sementes florestais, é notória a relação do fortalecimento dos estudos sobre espécies nativas e o crescente cunho ambiental da Legislação Florestal brasileira. Apesar de incentivado pela Legislação, o mercado de sementes nativas é muito informal e poucas são as espécies com testes laboratoriais protocolados nas Regras para Análise de Sementes (RAS). Entretanto, a Lei nº 10.711, ao regularizar a comercialização de sementes e mudas, concedeu subsídios legais para promover a formalização do setor de sementes florestais nativas. O cumprimento desta Lei está condicionado à padronização de metodologias laboratoriais para análise da qualidade dessas sementes. Por isto, a formulação de um anexo ou de uma RAS específica para sementes florestais nativas parece estar próximo. Este fato certamente consolidará esta fatia do setor sementeiro nacional. Mas quais foram os percursos que a ciência em sementes florestais nativas teve que transpor até esta padronização? Quais são as perspectivas de futuro para o setor de sementes florestais nativas? Estas são apenas algumas das perguntas que este trabalho pretende responder, embasado em perspectivas de organizações ambientais e silviculturais, como as Redes de Sementes.

By analyzing the trajectory of forest seed sector, it is widely known the relationship between the studies on native species and the Brazilian Forest Legislation. The Brazilian market for forest seed species is mostly informal and there are only a few species with laboratory tests registered in the Rules for Seed Testing (RAS). However, Law number 10,711, when ruling as to the marketing of seeds and seedlings, granted legal subsidies to promote the formalization of the forest seeds industry. Compliance with this law is conditioned to standardized laboratory methodologies for evaluating seed quality. For this reason, the formulation of a supplement or specific RAS for native forest seeds seems to be near. This fact will certainly consolidate the national seed industry sector. However, what were the paths that native forest seed science had to walk down to reach this standardization? What are the prospects for the future relating to the native forest seed sector? These are just some of the questions this work intends to answer, based on the perspectives of forestry and environmental organizations, such as the Seeds Networks.

The aim of this study was to evaluate the phytotoxic potential of aqueous extract of young leaves of Sapindus saponaria L. (soapberry) on the diaspore germination and seedling growth Lactuca sativa L. (lettuce) and Allium cepa L. (onion), as well as to determine, by bioassay-guided fractioning, whether the fractionated extracts of those leaves are phytotoxic to Triticum aestivum L. (wheat) coleoptiles. The aqueous extract was prepared using 100 g of dried plant material dissolved in 1000 ml of distilled water, resulting in a concentration of 10.0%. Distilled water was added in order to obtain dilutions of 7.5%, 5.0%, and 2.5%. The extraction was carried out with young leaves (in powder form) and organic solvents of various polarities. We fractioned the ethyl acetate extract using column chromatography. The phytotoxic potential of the aqueous extract of young leaves S. saponaria varied according to the receiving species and the concentration-dependent inhibitory effect. The ethyl acetate extract, specifically fraction 6 (57-70), had the greatest inhibitory effect on the elongation of wheat coleoptiles, indicating that the compounds responsible for the phytotoxic effect reside within this fraction.

O objetivo deste trabalho foi avaliar o potencial alelopático do extrato aquoso de folhas jovens e maduras de Sapindus saponaria (sabão-de-soldado) na germinação de diásporos e no crescimento de plântulas de capim-arroz (Echinochloa crus-galli) e corda-de-viola (Ipomoea grandifolia). O extrato aquoso foi preparado na proporção de 100 g de folhas secas e trituradas dissolvidas em 1000 mL de água destilada, produzindo-se o extrato considerado concentrado (10%). A partir deste, foram feitas diluições em água destilada para 7,5; 5,0 e 2,5%. No teste de crescimento de plântulas comparou-se o efeito desses extratos com o herbicida nicosulfuron. Os extratos de folhas maduras e jovens causaram atraso e redução na germinação dos diásporos e no comprimento das plântulas de capim-arroz e corda-de-viola, com efeitos mais intensos na concentração de 10%. No entanto, os resultados obtidos pelo extrato de folhas jovens foram mais similares ao efeito do herbicida, mostrando que o estágio de maturação da folha de S. saponaria interfere nos seus efeitos inibitórios e que esta espécie é eficiente no controle das plantas daninhas.

The objective of this work was to evaluate the allelopathic potential of aqueous extracts of young and mature leaves from Sapindus saponaria on diaspore germination and seedling growth of barnyardgrass (Echinochloa crus-galli) and morningglory (Ipomoea grandifolia). The aqueous extract was prepared in a proportion of 100 g of dried, ground leaves dissolved in 1000 mL of distilled water, resulting in a 10% extract concentrate. Dilutions of this concentrate were made with distilled water to 7.5, 5.0 and 2.5%. In seedling growth tests, we compared the effect of these extracts with the herbicide nicosulfuron. Both extracts of mature and young leaves caused delays and reductions in diaspore germination and seedling length of barnyardgrass and morningglory, with the most intense effects observed at a concentration of 10%. The effects of the young leaf extract were more similar to those observed with the herbicide, demonstrating that leaf maturation stage of S. saponaria affects its inhibitory effects on the growth of other plants and that this species is effective in controlling weeds.

Sapindus saponaria (soapberry) is a species that presents a great diversity of chemical compounds, such as saponins; however, few studies have examined the allelopathic effect of this species. Therefore, this study provides an evaluation of the allelopathic potential of aqueous extracts of the roots and mature leaves of S. saponaria on the germination of diaspores and seedlings growth of lettuce (Lactuca sativa) and onion (Allium cepa). The aqueous extract was prepared in the proportion of 100 g of dry plant material in 1,000 mL of distilled water (a concentration of 10% w v-1), and diluted with distilled water to 7.5, 5.0 and 2.5% concentrations. The mature leaf extracts caused delay and decrease in the germination process of the lettuce and onion diaspores, with inhibitory effect concentration-dependent, while the root extracts showed no allelopathic effects on the germination process. Both extracts caused abnormalities and inhibited the growth of shoot and root seedlings.

Pseudobombax tomentosum y P. longiflorum son árboles comunes en la región del Cerrado, pero la primera especie es más común en los bordes del bosque mientras que el segundo está presente en áreas abiertas del cerrado. Este trabajo tuvo como objetivo investigar las diferencias en la germinación de las semillas y el crecimiento de ambas especies. Los individuos fueron recolectados en áreas del Cerrado, la región de savanas neotropicales en el centro de Brasil. Fueron utilizados para cada especie cuatro repeticiones con 25 semillas cada una para el experimento de germinación, distribuidas al azar en la cámara de germinación a 25ºC. Las plántulas fueron evaluadas en cuanto al crecimiento inicial hasta 67 días después de la emergencia de la plántula. Algunas plantas se mantuvieron para la evaluación de la biomasa durante nueve meses, y luego se mideron para evaluar diferencias en el crecimiento y distribución de masas entre especies. Ambas presentaron la misma capacidad germinativa (cerca de 100%) y tiempo medio de germinación (alrededor de 12 días). Sin embargo, P. longiflorum presentó una germinación más dispersa en el tiempo, con valores más altos de coeficiente de variación de tiempo de germinación y el índice de incertidumbre, y valores más bajos de la sincronización que P. tomentosum. Las dos especies demostraron básicamente el mismo patrón de crecimiento, pero P. tomentosum presentó valores más pequeños en la altura del meristemo apical, diámetro de las estructuras subterráneas (sobre todo las raíces), masa seca de la estructura aérea, estructura subterránea y plántulas en comparación con P. longiflorum. Ambas especies asimilaron más masa seca en las estructuras subterráneas en detrimento de las aéreas. Esto probablemente permite una conducta de rebrote que evita el estrés hídrico y la acción perjudicial de incendios típicos de las zonas del cerrado abierto.

Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100%) and mean germination time (ca. 12 days). However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots), dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas. Rev. Biol. Trop. 59 (4): 1915-1925. Epub 2011 December 01.

Copaifera langsdorffii é uma espécie em perigo de extinção, com dormência múltipla em suas sementes e baixa resistência ao armazenamento. Nesse sentido, é importante saber se as sementes perdem viabilidade a partir do ponto de maturidade fisiológica e se resistem à perda de água durante o armazenamento. Quatro experimentos foram instalados com sementes coletadas em julho (matriz 1) e agosto de 2005 (matriz 2), no Vale do Rio Araguari, MG, dois com sementes recém-colhidas e dois com sementes armazenadas em câmara fria. A perda de 31% de água das sementes coletadas no solo, em relação às colhidas de frutos aderidos à árvore, reduziu em aproximadamente 10% o porcentual de emergência. A presença do arilo nas sementes recém-colhidas causou aumento do coeficiente de variação de emergência, indicando que essa estrutura possui substâncias inibidoras de germinação. Com o armazenamento, as sementes perderam viabilidade, diminuindo significativamente os porcentuais de emergência, o que indica que as sementes dessa espécie possuem certo grau de recalcitrância, com baixa resistência à perda de água após a maturidade fisiológica. Para a obtenção de maior número de mudas, em menor tempo e com maior sincronia, recomenda-se a utilização de sementes oriundas de frutos recém-abertos, ainda aderidos à árvore, com semeadura sem arilo e com escarificação.

Copaifera langsdorffii is a threatened species that presents seeds with multiple dormancy and low resistance to storage. Thus, it is interesting to know if the seeds lose viability from the physiological maturity point and if they resist to desiccation during the storage period. Four experiments were conducted using seeds from the Araguari River Valley, MG (matrix 1, July and matrix 2, August 2005). Two of them had newly-collected seeds and the other two used seeds stored in cold chamber. The loss of 31% of water from the seeds collected from the soil in relation to the seeds collected from the tree reduced the percentage of emergence in about 10%. The presence of aril increased the value of the coefficient of variation of the emergence, indicating the presence of germination inhibitors in this part of the seeds. The seeds had lost viability after storage, reducing significantly the percentages of emergence. This characteristic indicates that seeds of this species have some degree of recalcitrance. To obtain a high number of seedlings in short time, with high synchrony, seeds collected from newly-opened fruits, directly of the tree, without aril, and scarified are recommended.

Brassica chinensis var. parachinensis é uma hortaliça folhosa, de ciclo curto, introduzida no Brasil em 1992, em função de sua excelente qualidade nutricional. Apresenta elevado teor de β-caroteno, vitamina C, Ca e Fe, o que a torna importante alimento, especialmente no combate à anemia. Este trabalho teve como objetivo avaliar a produtividade biológica e agronômica da couve-da-Malásia, cultivada sob deficiência de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo e Zn e comparada com o tratamento-testemunha que incluiu todos os macro e micronutrientes. As plantas cultivadas na ausência de N e P conseguiram completar o ciclo, mas foram significativamente menos produtivas e pouco desenvolvidas em relação às que receberam nutrição completa. Além disso, apresentaram coloração das folhas verde-acinzentada e arroxeamento do pecíolo e nervuras. Na ausência de B, todas as plantas morreram entre 30 e 37 dias após a semeadura e, na ausência de S, elas não produziram frutos, o que mostra a importância destes dois nutrientes para essa Brassicaceae.

Brassica chinensis var. parachinensis is a vegetable with short cycle, which was introduced in Brazil in 1992 due to its high nutritional qualities. It presents high concentration of β-carotene, vitamin C, Ca, and Fe, becoming an important food for the prevention of anemia. The aim of this paper was to evaluate the biological and agronomic productivity of plants grown under N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo, and Zn deficiency. The results were compared with plants grown with all macro and micronutrients. Plants cultured without N and P completed their cycle, but had lower yield than those cultured with complete nutrition. Additionally, they had green-grayish leaves, and purple petiole and veins. Plants cultured without B died between 30 and 37 days after sowing, and without S they did not produce fruits. These results show the importance of S and B to this Brassicaceae.

O presente trabalho apresenta o tratamento taxonômico para as espécies de Thelypteris pertencentes aos subgêneros Goniopteris e Meniscium que ocorrem na Estação Ecológica do Panga. A família mostrou-se uma das mais representativas da pteridoflora local, com 14 espécies de Thelypteris segregadas em quatro subgêneros (Amauropelta, Cyclosorus, Goniopteris e Meniscium). Na área de estudo, o subgênero Goniopteris está representado por duas espécies, Thelypteris biformata (Rosenst.) R.M. Tryon e T. jamesonii (Hook.) R.M. Tryon, e Meniscium por três espécies, T. chrysodioides (Fée) C.V. Morton var. goyazensis (Maxon & C.V. Morton) C.V. Morton, T. salzmannii (Fée) C.V. Morton e T. serrata (Cav.) Alston. São apresentadas descrições e chaves para identificação das espécies, bem como suas distribuições geográficas e ilustrações.

This paper presents the taxonomic treatment for the species of Thelypteris, subgenera Goniopteris and Meniscium, collected in the Ecological Station of Panga. Thelypteridaceae is one of the richest families in the area, with 14 species of Thelypteris segregated in four subgenera (Amauropelta, Cyclosorus, Goniopteris, and Meniscium). Two species of subgenus Goniopteris, Thelypteris biformata (Rosenst.) R.M. Tryon and T. jamesonii (Hook.) R.M. Tryon, and three species of subgenus Meniscium, T. chrysodioides (Fée) C.V. Morton var. goyazensis (Maxon & C.V. Morton) C.V. Morton, T. salzmannii (Fée) C.V. Morton, and T. serrata (Cav.) Alston were recorded. Descriptions and identifications keys, as well as geographical distribution and illustrations are included.