ABSTRACT Drimys brasiliensis Miers, popularly known as cataia, is a tree species native to the Atlantic Forest that has phytochemical, phytotherapeutic, aromatic and economic importance, with wide use in folk medicine. It is considered a species of difficult multiplication via seeds, presenting dormancy due to embryonic immaturity. Thus, the objective of this study was to analyze the vegetative rescue, in vitro establishment and propagation by way of cuttings of Drimys brasiliensis. For the rescue, the girdling techniques were applied at 30 and 90 cm from the ground, semi-girdling at 30 cm from the ground and pruned branches conditioned vertically and horizontally, being evaluated the shoot emission capacity. With the shoots obtained by vegetative rescue, the explants used for in vitro establishment were made, evaluating different immersion times in sodium hypochlorite 1.0 % (v/v) (0, 10, 15 and 20 minutes). The percentages of total, bacterial, fungal contamination and phenolic oxidation were evaluated. On the cuttings, shoots from vegetative rescue, from the aerial part of an adult individual and from detached branches were tested and placed in a mini-tunnel. The percentage of cuttings survival, percentage of cuttings with callus and percentage of rooting were evaluated. Regarding the vegetative rescue, the technique of pruned branches resulted in the induction of shoots, highlighting the branches conditioned vertically (100%). In the in vitro establishment, the immersion in sodium hypochlorite (1%) for 20 minutes proved to be efficient in the control of fungal contamination, however, no significant differences were observed in relation to the control of bacterial contamination. In cuttings, the use of cuttings from pruned branches or girdling/semi-girdling showed potential for these techniques in the cloning of the species, obtaining results close to 10% rooting. In general, the species has the potential for vegetative propagation, however, adjustments are necessary in the in vitro establishment and cutting protocols.

RESUMO Drimys brasiliensis Miers, conhecida popularmente por cataia, é uma espécie arbórea nativa da Mata Atlântica que apresenta importância fitoquímica, fitoterapêutica, aromática e econômica, com amplo uso na medicina popular. É considerada uma espécie de difícil multiplicação via sementes, apresentando dormência por imaturidade embrionária. Assim, objetivou-se com este estudo analisar o resgate vegetativo, estabelecimento in vitro e a propagação via estaquia de Drimys brasiliensis. Para o resgate, realizou-se a aplicação das técnicas de anelamento a 30 e 90 cm do solo, semianelamento a 30 cm do solo e galhos podados acondicionados vertical e horizontalmente, sendo avaliada a capacidade de emissão de brotações. Com as brotações obtidas pelo resgate vegetativo, foram confeccionados os explantes utilizados para o estabelecimento in vitro, avaliando diferentes tempos de imersão em hipoclorito de sódio 1,0 % (v/v) (0, 10, 15 e 20 minutos). Foram avaliadas as percentagens de contaminação total, bacteriana, fúngica e oxidação fenólica. Na estaquia foram testadas brotações oriundas do resgate vegetativo, da parte aérea de indivíduo adulto e de galhos destacados e acondicionados em mini-túnel. Avaliaram-se a porcentagem de sobrevivência das estacas, porcentagem de estacas com calos e porcentagem de enraizamento. Em relação ao resgate vegetativo, a técnica de galhos podados resultou na indução de brotações, destacando os galhos acondicionados verticalmente (100%). No estabelecimento in vitro, a imersão em hipoclorito de sódio (1%) por 20 minutos se mostrou eficiente no controle da contaminação por fungos, entretanto, não foram observadas diferenças significativas em relação ao controle de contaminação bacteriana. Na estaquia, o uso de estacas provenientes de galhos podados ou anelamento/semianelamento mostrou potencial para estas técnicas na clonagem da espécie, obtendo resultados próximos a 10% de enraizamento. No geral, a espécie apresenta potencial de propagação vegetativa, contudo, são necessários ajustes nos protocolos de estabelecimento in vitro e estaquia.

Abstract The objective of this research was to evaluate the presence of physical dormancy in seeds of Psidium cattleianum (araçá), obtained from fruits of different stages of maturation. The fruits were collected from 15 parent plants in the municipality of Lages-SC and classified, according to the Munsell color chart, in yellowish red (5YR5 / 7), red (10R5 / 6) and dark red (10R3 / 6). After beneficiation, with the aid of a sieve and running water, the seeds of the fruits of the three colors were evaluated for: water content, dry mass, first germination count, germination, abnormal seedlings, dead seeds, first emergency count, emergency, days to start the emergency, emergency speed index, water soak curve and methylene blue soak. The water contents were 22.02, 23.53 e 23.08%, for seeds of colors 1, 2 and 3, respectively. There was no significant difference between the seeds of the fruits of the three colors for all variables analyzed, except for the emergence speed index, where seeds of colors 2 fruits were more vigorous in relation to the seeds of the other colors. The soaking process was characterized by a three-phase curve, with root protrusion starting at 275, 323, 323 hours, for fruit seeds of colors 1, 2 and 3, respectively. Methylene blue entered the seeds on the first day, with complete absorption in 371 h (16 days). The results showed that the seeds of the three colors of the fruit were already at physiological maturity, with similar results in relation to the dry mass. It is concluded that mature seeds of Psidium cattleianum Sabine do not have physical dormancy, regardless of the colors of the fruits studied.

Resumo Objetivou-se com o trabalho avaliar a presença de dormência física em sementes de Psidium cattleianum (araçá), obtidas de frutos de diferentes estádios de maturação. Os frutos foram coletados em 15 plantas matrizes no município de Lages-SC e classificados, de acordo com a tabela de cores de Munsell, em vermelho amarelado (5YR5/7), vermelho (10R5/6) e vermelho escuro (10R3/6). Após o beneficiamento, com auxílio de peneira e água corrente, as sementes dos frutos das três colorações foram avaliadas quanto: teor de água, massa seca, primeira contagem de germinação, germinação, plântulas anormais, sementes mortas, primeira contagem de emergência, emergência, dias para iniciar a emergência, índice de velocidade de emergência, curva de embebição em água e embebição em azul de metileno. Os teores de água estavam em 22,02; 23,53 e 23,08% para as sementes das colorações 1, 2 e 3, respectivamente. Não houve diferença significativa entre as sementes dos frutos das três colorações para todas as variáveis analisadas, exceto para o índice de velocidade de emergência, em que sementes de frutos da coloração 2 demonstraram-se mais vigorosas em relação às sementes das demais colorações. O processo de embebição em água foi caracterizado por uma curva trifásica, com início da protrusão radicular em 275, 323, 323 horas, para sementes de frutos de colorações 1, 2 e 3, respectivamente. Observou-se entrada do azul de metileno nas sementes já no primeiro dia, com absorção completa em 371 h (16 dias). Com base nos resultados obtidos, verifica-se que as sementes das três colorações do fruto já estavam na maturidade fisiológica, com resultados semelhantes em relação à massa seca. Conclui-se que sementes maduras de Psidium cattleianum Sabine não possuem dormência física, independente da coloração dos frutos estudados.

ABSTRACT The objective of this work was to identify and describe the morphological aspects of the pyrene and the different stages of developing embryos of Ilex paraguariensis. The pyrenes were collected in the year 2016 and 2017, of ripe fruits. The pyrenes, a total of 400 per site and year of collection, remained for 24 h immersed in water for the section and internal observation. The pyrenes, with the visualized embryo, were used for the anatomical description and fixed for the histological evaluation. They were fixed in paraformaldehyde solution and included in Leica™ historesin. The samples were sectioned in Leica microtome with a thickness of 7 μm, and the sections were stained with Toluidine Blue. The pyrenes are formed by endocarp, integument, endosperm, and embryo. The embryos were classified in the globular, heart (occupying approximately 10% of the length of the seed), post heart (15% of length), torpedo (20% of length), and mature (40% of length) stages; and were located below the micropyle, aligned to the external point. The region surrounding the embryo, called the cavity, consists of a lignified layer.

ABSTRACT This study aimed to determine the main causes of low germination of Zanthoxylum rhoifolium Lam. (Rutaceae) seeds. Initially, the physical and physiological qualities were evaluated in seeds from four areas (lots) (Step I). Then, tests were performed (Step II) to determine physical dormancy (imbibition in water and methylene blue), physiological (germination test with scarification) and morphological (analysis of the embryo), in addition to histochemical analysis and (Step III) bioassay in aqueous and hydroalcoholic extracts. In Step I, a low germination was observed in all evaluated lots (≤ 1.0%); however, in the tetrazolium test, a high viability was verified for the Dois Vizinhos lot (88%). The lots showed differences in their physical aspects, with the predominance of seeds with damage. In Stage II, developed embryos were verified and there has no germination without the tegument. The methylene blue and histochemical test indicated the presence of an impermeable and thick tegmen. The bioessays with hydroalcoholic extracts indicated the presence of germination inhibitor(s). The main causes associated with low germination of Z. rhoifolium seeds are attributed to the combined dormancy due to an impermeable tegmen and some non-specific physiological dormancy, as well as the presence of damaged seeds. The seeds also contain germination inhibitors.

Resumo Pirênios de Ilex parguariensis, popularmente conhecida como erva-mate, foram classificados como dormentes. O objetivo deste estudo foi investigar as causas da dormência dos pirênios de Ilex paraguariensis. Para isso, foram realizados os seguintes testes: a) Dormência física: taxa de absorção em água e em azul de metileno; detecção de lignina e compostos lipofílicos no endocarpo e tegumento; b) Dormência fisiológica: bioensaios em sementes de alface, detecção e quantificação de compostos fenólicos; c) Dormência morfológica: análise embrionária. Para a taxa de absorção, observou-se um aumento na massa dos pirênios, porém, quando a embebição foi realizada em azul de metileno, a absorção ocorreu apenas no endocarpo. A lignina também foi observada na forma de uma camada de esclerênquima próxima ao tegumento da semente. Semelhantemente compostos lipofílicos foram observados em uma camada externa ao endosperma. Os bioensaios com sementes de alface indicaram a presença de inibidores químicos. Na avaliação morfológica dos pirênios, apenas 55,5% dos embriões foram visualizados e estavam nos estágios globular ou coração. Pirênios de Ilex paraguariensis possuem dormência combinada: física (não há absorção de água), morfológica (devido ao subdesenvolvimento do embrião) e há evidências de dormência fisiológica (presença de inibidores); Contudo, recomenda-se investigar os agentes inibidores.

Abstract Ilex parguariensis pyrenes, popularly known as “yerba mate”, were classified as dormant. This study aim to investigated the causes of dormancy in Ilex paraguariensis’ pyrenes. Hence, the following tests were performed: a) Physical dormancy: rate of absorption in water and methylene blue; detection of lignin and lipophilic compounds in the endocarp and integument; b) Physiological dormancy: bioassays in lettuce seeds, detection, and quantification of phenolic compounds; c) Morphological dormancy: embryo analysis. For the absorption rate, an increase was observed in the mass of the pyrenes, however, when imbibition was performed in methylene blue, absorption only occurred in the endocarp. Lignin was also observed in the form of a sclerenchyma layer next to the seed coat. Similarly, lipophilic compounds were observed in a layer, external to the endosperm. The bioassays with lettuce seeds indicated the presence of chemical inhibitors. In the morphological evaluation of the pyrenes, only 55.5% of the embryos were visualized and they were in the globular or heart stages. Ilex paraguariensis pyrenes have combined dormancy: physical (not water absorption), morphological (due to the underdeveloped embryo), and there are shreds of evidence about physiological dormancy (presence of inhibitors); however, it is recommended to investigate the inhibitory agent.

Abstract There has been an increase in the occurrence of fungal diseases in Ilex paraguariensis A. St.-Hill. (yerba mate) resulting from their domestication. Seed health tests may indicate pathogens prior to sowing, enabling their control. Our study sought to compare the efficacy of fungi detection methods on yerba mate seeds. Seeds from four lots were subjected to the following detection methods: BDA, V8 and filter paper; as well as the performance of asepsis with 1% sodium hypochlorite and 70% alcohol. The fungi found in the lots were: Penicillium spp., Cladosporium spp., Aureobasidium melanogenum, Aspergillus spp., Pestalotia spp., Nigrospora spp., Trichoderma spp., Fusarium graminearum, F. oxysporum and F. guttiforme. The asepsis in the seeds reduced the occurrence of contaminating organisms. There were differences between the evaluated lots regarding fungal incidence. In general, the BDA and V8 culture media showed better results in fungal detection.

Abstract This study sought to determine the possible causes of the low seed quality of I. paraguariensis A. St. Hil. Seeds from six samples collected at different sites were classified as empty, decayed, herbivorous and full. Viability was assessed by tetrazolium test in seeds filled with a visualized embryo. High amounts of empty and deteriorated seeds (54% to 93%) were verified in four of the evaluated samples, and insect attack was observed in two samples. The viability of visualized embryo-filled seeds was 83% to 100%. Low quality generally results from the presence of empty and deteriorated seeds, as well as dormancy.

Abstract Gymnanthes klotzschiana is a tree native to the Atlantic Forest Biome. The objective of this study was to analyze the synchronization of five phenophases and their correlation with environmental factors during two years of survey in two distinct areas (Area 1: Mixed Alluvial Ombrophilous Forest; Area 2: Montane Semi-deciduous Seasonal Forest). Ten individuals were randomly selected in each area, with the following variables being studied: leaf fall and budding, flowering, and immature and ripe fruit production. The activity index and the intensity index were determined for each phenological event. Timing and interactions with environmental factors were tested using Spearman’s correlation. The photoperiod correlated with all phenophases and precipitation did not correlate with any. There was synchronization in the foliar fall and foliage in the two areas. The species can be characterized as semi-deciduous. Flowering and fruiting were annual, with the highest intensity of fruit production occurring in Area 1.

Abstract The objective of this study was to assess hypoxia tolerance in Gymnanthes klotzschiana seeds harvested in two areas (Area 1 - subject to flooding; and Area 2 - not subject to flooding) by the imbibition curve, vigor and germination. Seeds of the two areas were submitted to: one (T-1d), three (T-3d), five (T-5d), ten (T-10d) and twenty days under hypoxia (T-20d); in addition to the control (T-0d). All treatments presented three germination stages. The highest germination was achieved in Area 1 T-1d (90%) and the lowest in Area 2 T-20d (31%). The Area 1 seeds required less time and water content to finish their germination, and they presented greater tolerance to hypoxia; a fact proven by the germination and vigor results. G. klotzschiana seeds harvested in an area subject to flooding are more tolerant to hypoxia and are recommended for restoration projects in this type of area.

Resumo A estratificação das sementes de Ilex paraguariensis A. St.-Hill. (erva-mate) em areia úmida por períodos de quatro a seis meses é uma prática comum em viveiros, utilizada para a superação de dormência das mesmas. Entretanto, este processo pode apresentar difícil controle fitossanitário, devido ao elevado grau de umidade e a grande concentração de sementes no mesmo local. Assim, objetivou-se verificar a influência da estratificação em areia autoclavada na qualidade sanitária de sementes de erva-mate. Sementes de quatro lotes foram submetidas à estratificação em areia úmida autoclavada, durante três e seis meses, tendo sua sanidade avaliada em meio BDA ao final destes períodos, assim como em sementes que não passaram por estratificação. Ao final do período de estratificação, as sementes apresentaram aspecto superficial escurecido, o que pode estar ligado à ação dos fungos na degradação do endocarpo. Foram identificados: Fusarium graminearum, Fusarium oxysporum, Fusarium guttiforme, Paecilomyces sp., Aspergillus sp., Penicillium sp. Já Aureobasidium melanogenum, Trichoderma sp., Curvularia sp., Rhizopus sp., Alternaria sp., Cladosporium sp. e Bipolaris sp. tiveram menores ocorrências. Observou-se a redução de Fusarium graminearum, Fusarium oxysporum, Fusarium guttiforme, Aspergillus sp. e Penicillium sp. após a estratificação em areia autoclavada e o gênero Paecilomyces somente foi observado aos 180 dias de estratificação, podendo estar relacionado com a degradação do endocarpo de sementes de Ilex paraguariensis.

Abstract The stratification of Ilex paraguariensis seeds (yerba mate) in wet sand for periods of four to six months is a common practice in nurseries, used to overcome their dormancy. However, this process may present difficult phytosanitary control due to the high moisture content and the high concentration of seeds in the same place. Thus, the present work had the objective of verifying the influence of the stratification in autoclaved sand on the sanitary quality of yerba mate seeds from different lots. Seeds of four lots were submitted to wet stratification for three and six months, and their sanity was evaluated at the end of these periods, as well as seeds that did not undergo stratification. At the end of the stratification period, the seeds had a darkened surface appearance, which may be related to the action of the fungi in the degradation of the endocarp. These ones were identified: Fusarium graminearum, Fusarium oxysporum, Fusarium guttiforme, Paecilomyces sp., Aspergillus sp., Penicillium sp. Already Aureobasidium melanogenum, Trichoderma sp., Curvularia sp., Rhizopus sp., Alternaria sp., Cladosporium sp. and Bipolaris sp. had fewer occurrences. Observed reduction of Fusarium graminearum, Fusarium oxysporum, Fusarium guttiforme, Aspergillus sp. and Penicillium sp. after stratification and the genera Paecilomyces was only observed at 180 days of stratification, and may be related to the degradation of the endocarp of Ilex paraguariensis seeds.

SUMMARY: Sequoia sempervirens is a fast-growing, long-lived tree with pest-resistant wood. The objective of this study was to quantify the adventitious rooting ability of sequoia clones in two environments as well as determining rooting behavior during the evaluation period. Mini-cuttings of five clones grown in a clonal mini-garden were planted for rooting in two different environments: a mini-tunnel and an intermittently fogging greenhouse. Weekly assessments (from 30 to 93 days) of the variables were performed: survival, rooted mini-cuttings and number of roots emitted. Rooting speed varied in relation to the clones, occurring mainly between 50 and 60 days after planting, with the appearance of new roots between 70 and 80 days. The cultivation environment promoted distinct responses in the rooting process, being earlier in the greenhouse environment, although with a higher index in the mini-tunnel at the end of the evaluation. The process of differentiation of mini-cuttings occurs initially with the formation of calluses, around 15 days, followed by rooting (between 30 and 60 days) and the subsequent appearance of new roots. The rooting of sequoia mini-cuttings can be done in a mini-tunnel, with good indexes for all clones. It is recommended to keep mini-cuttings in this environment for 90 days for good root formation.

RESUMEN: Sequoia sempervirens es un árbol longevo de rápido crecimiento con madera resistente a plagas. El objetivo de este estudio fue cuantificar la capacidad de enraizamiento adventicio de clones de S. sempervirens en dos ambientes, así como determinar el comportamiento de enraizamiento durante el período de evaluación. Se plantaron miniestaquillas de cinco clones cultivados en minihuertos clonales para enraizar en dos ambientes diferentes: mini túnel e invernadero de nebulización intermitente. Se realizaron evaluaciones semanales (de 30 a 93 días) de las variables: supervivencia (%), mini estaquillas enraizadas (%) y raíces emitidas. La velocidad de enraizamiento varió en relación con los clones, ocurriendo principalmente entre 50 y 60 días después de plantados, con la aparición de nuevas raíces entre 70 y 80 días. El ambiente de cultivo promovió respuestas distintas en el proceso de enraizamiento, siendo más temprano en el invernadero de nebulización intermitente, pero con un índice más alto en el mini túnel al final de la evaluación. El proceso de diferenciación de mini estaquillas ocurrió inicialmente con la formación de callos, alrededor de 15 días, seguido de enraizamiento (entre 30 y 60 días) y la posterior aparición de nuevas raíces. El enraizamiento de las mini estaquillas se puede hacer en un mini túnel, con buenos índices para todos los clones, y se recomienda mantener las mini estaquillas en este ambiente durante 90 días para una buena formación de raíces.

RESUMO Sequoia é uma espécie de rápido crescimento, longeva e de madeira durável. O objetivo do estudo foi testar diferentes métodos de resgate vegetativo em árvores adultas de Sequoia sempervirens, realizados em distintas épocas do ano e posterior enraizamento de estacas individualizadas por planta matriz. Resgataram-se 24 indivíduos de sequoia, aplicando-se anelamento e semianelamento em três diferentes alturas (-10, 0 e 30 cm). A primeira coleta foi efetuada 90 dias após aplicação dos tratamentos, sendo repetida aos 150, 240 e 360 dias. Contabilizou-se a porcentagem de árvores com brotações e o número de brotações por matriz. Em todas as coletas as brotações originaram estacas que foram colocadas para enraizar em estufim. No enraizamento das estacas analisou-se a sobrevivência (%), enraizamento (%) e número de raízes por matriz por coleta. O resgate vegetativo da espécie mostrou-se eficiente na produção de brotações para a estaquia, destacando-se o anelamento a 30 cm e o semianelamento a -10 cm. Entretanto, há dificuldade em definir qual o melhor método, principalmente em função do efeito genético entre matrizes. O enraizamento de estacas do material resgatado apresentou bons resultados (média >65%), também com grande diferença entre as matrizes. Diferentes épocas de estaquia alteraram o potencial de enraizamento, contudo, com altos índices de enraizamento em todas as estações do ano, principalmente no verão. Sequoia sempervirens apresenta potencial de resgate vegetativo e clonagem por estaquia, sendo possível conduzir novos trabalhos com vistas a fixação de clones.

ABSTRACT Sequoia is a fast-growing, long-living species, producing durable timber. The aim of this study was to test different methods for the vegetative rescue of Sequoia sempervirens trees over 40 years old, made at different periods of the year, and, later, testing the rooting of individualized cuttings in planned arrays. Twenty-four individual sequoias were rescued, applying girdling and semi-girdling at three different heights (-10, 0, and 30 cm). The first collection was made 90 days after application of the treatments, being repeated at 150, 240, and 360 days. The percentage of budding trees and the number of shoots per array were registered. In all collections, shoots produced cuttings, which were placed for rooting in mini-tunnels. Cutting survival (%), rooting (%), and number of roots were registered, per array, and per collection. The species vegetative rescue proved to be efficient for the production of shoots for stem cuttings, especially with girdling at 30 cm and semi-girdling at -10 cm. However, it is difficult to define the best method, mainly because of the genetic effect among stock plants. The rooting of cuttings, of recovered material, presented good results (average >65%), also with great differences among stock plants. The potential for rooting of cuttings varied according to different planting periods, with high rooting rates in all seasons, especially in summer. Sequoia sempervirens shows the potential for vegetative rescue and cloning by rooting of cuttings, and this may lead to new studies, with a view towards fixing clones.

RESUMO Acca sellowiana é uma espécie frutífera nativa da Região Sul do Brasil que está despertando grande interesse econômico devido ao alto potencial organoléptico de seus frutos. A principal forma de propagação da espécie é via sexuada. Objetivando determinar a qualidade sanitária das sementes, foram comparadas três formas de detecção de fungos, com ou sem a assepsia superficial, em sementes oriundas de quatro municípios do Estado do Rio Grande do Sul e de três municípios do Estado de Santa Catarina. Foram testados os meios de cultura Batata-Dextrose-Ágar (BDA), V8 (suco de tomate) e o método Blotter Test. Foram identificados os seguintes fungos: Aspergillus niger, Aspergillus flavus, Penicillium sp., Colletotrichum gloeosporioides, Fusarium sp., Curvularia sp., Alternaria sp., Trichoderma sp., Epicoccum sp. e Phomopsis sp. Os meios agarizados são mais sensíveis na detecção de fungos em sementes de goiaba serrana. A assepsia das sementes reduz a incidência de fungos infestantes.

ABSTRACT Acca sllowiana (Berg) Burret is a native fruit species in southern Brazil, which is attracting great interest due to the high economic potential of its fruit organoleptic potential; the main form of propagation of the species is sexual way. Aiming to determine the sanitary quality of seeds, three forms of detection of fungi were compared with and without surface sterilization. The seeds were derived from four counties in the state of Rio Grande do Sul and three counties in the state of Santa Catarina. The culture media of Potato Dextrose Agar (PDA), V8 (tomato juice) and the method of “Blotter Test” were tested. The following fungi were identified: Aspergillus niger, Aspergillus flavus, Penicillium sp., Colletotrichum gloeosporioides, Fusarium sp., Curvularia sp., Alternaria sp. Trichoderma sp. Epicoccum spp. and Phomopsis sp. The agarized media are more sensitive in the detection of fungi in Acca sellowiana seeds. The sterilization of seeds reduces the incidence of weed fungi.

RESUMO Objetivou-se avaliar a influência de tipos de secagem na qualidade de sementes, consideradas recalcitrantes, de Ocotea puberula e determinar o seu grau de umidade crítico e grau letal. Sementes colhidas em Brunópolis, SC, com teor de água inicial de 38%, foram secas até 18%, com gradientes de 2%; utilizando a equação de peso alvo para garantir este gradiente, em estufa (35 oC) e em dessecador com sílica-gel (25 oC). Após cada secagem, as sementes foram avaliadas quanto ao teor de água, porcentagem e velocidade (IVG) de germinação, T50 e tetrazólio. Foi observado que até 32% de teor de água não houve alteração na qualidade das sementes, independente do tipo de secagem, sendo verificada significativa perda de germinação após esse valor. Conclui-se que o tipo de secagem não influencia na qualidade dessas sementes; porém, por tratar-se de uma semente recalcitrante, a redução do teor de água abaixo de 32% prejudica a germinação, sendo seu grau de umidade crítico e sementes com 22% de teor de água não tiveram germinação, sendo neste estudo o grau de umidade letal desta espécie.

ABSTRACT The objective of this work was to evaluate the influence of types of drying on seeds' quality, as recalcitrant, Ocotea puberula and determine their degree of critical humidity and lethal degree. Seeds harvested in Brunópolis, SC, with an initial moisture content of 38%, were dried to 18%, with gradients of 2%; using the equation of target weight to ensure that gradient in the stove (35 oC) and in a desiccator with silica gel (25 oC). After drying, the seeds were evaluated for water content, percentage and germination speed index (GSI), tetrazolium and T50. It was observed that up to 32% water content did not change in seed quality, regardless of the type of drying and verified significant loss of germination after this value. We conclude that the type of drying does not affect the quality of the seed; however, because it is a recalcitrant seed, reducing the water content below 32% decreased germination, and its degree of critical humidity and seeds with 22% moisture content had no germination in this study is the degree of lethal humidity of this species.

RESUMO Objetivou-se verificar a viabilidade de sementes e a integridade do DNA de Ocotea puberula durante armazenamento, com e sem o fruto. Sementes de cinco lotes foram armazenadas com e sem fruto, em câmara fria e seca (UR 40% ± 3% e temp. 10 °C ± 2 °C), pelos períodos de 0, 3, 6 e 9 meses. A cada período foram determinados o teor de água, germinação (%), tetrazólio (%) e integridade do DNA. O teste de germinação foi realizado em papel germitest, em germinador a 30 °C, sob luz constante. O teste de tetrazólio foi realizado com solução na concentração de 0,5%, pelo período de 1 hora. A integridade do DNA das sementes foi analisada em gel de agarose e a concentração de DNA mensurada com espectrômetro NanoDrop®. Foi verificado que somente sementes armazenadas sem o fruto mantiveram sua germinação por até três meses. Após esse período, a germinação das sementes foi reduzindo-se gradativamente, sendo nula aos 9 meses. Na análise da integridade do DNA de sementes foi possível visualizar sua degradação ao longo do armazenamento. Sementes de O. puberula, com ou sem fruto, armazenadas em sacos de papel kraft reduzem sua viabilidade e integridade de DNA após 3 meses de armazenamento em câmara fria e seca.

ABSTRACT This study aimed to verify the DNA integrity and viability of Ocotea puberula seeds, with and without fruit, during storage. Seeds of five lots were stored, with and without fruit, in cold and dry chamber (40% ± 3% RH; 10 °C ± 2 °C) for 0, 3, 6, and 9 months. The following attributes were determined at each period: water content, germination potential (%), tetrazolium (%), and DNA integrity. Seed germination was conducted in germitest paper, in germinator at 30 °C under constant light. The tetrazolium test was performed in 0.5% solution for 1 hour. The DNA integrity of seeds was analyzed in agarose gel and DNA concentration was measured using a NanoDrop® spectrometer. The results showed that only seeds without fruit maintained germination for three months; after this period, the germination of seeds reduced gradually, becoming null after nine months. Seed degradation during storage was observed in the DNA integrity analysis. Ocotea puberula seeds, with or without fruit, stored in Kraft paper bags in cold and dry chamber had their viability and DNA integrity reduced after three months.