Luciana Magda de Oliveira

Trithrinax acanthocoma Drude é uma palmeira rara, especificamente encontrada em Floresta Ombrófila Mista no sul do Brasil, desempenha um papel significativo nos ecossistemas florestais, fornecendo habitat e alimento para a fauna local. Porém, são escassas as informações a respeito da presença de dormência em pirênios da espécie, dificultando a produção de suas mudas. Objetivou-se investigar a(s) causa(s) da dormência em pirênios de T. acanthocoma. Para isso, foram realizados os seguintes testes: absorção em azul de metileno com pirênios íntegros e escarificados; quantificação de compostos fenólicos totais; bioensaio em sementes de alface; análise morfologia dos pirênios e embriões, também foram realizados testes histoquímicos para avaliar a presença de lipídios, proteínas, lignina e compostos fenólicos. Na embebição em azul de metileno, ocorreu a absorção apenas nos pirênios escarificados. Na avalição morfológica, o embrião, apesar de apresentar algumas estruturas, é muito pequeno em relação ao endosperma, o que sugere que seja subdesenvolvido. Na avaliação histoquímica, foram observados lignina, lipídios e fenóis; Na quantificação de fenóis apresentou níveis consideráveis nos pirênios e no bioensaio com sementes de alface não detectaram a presença de inibidores solúveis em água. Conclui-se que as prováveis causas de dormência de pirênios de T. acanthocoma são físicas e morfológicas.

O objetivo deste trabalho foi descrever os métodos de germinação, as características da viabilidade e a classificação fisiológica em armazenamento de sementes de Siphoneugena reitzii D. Legrand, Myrtaceae ocorre em locais de alta altitude da floresta ombrófila mista. As sementes foram coletadas em cinco matrizes localizadas na “Fazenda das Nascentes" – RPPN Serra da Farofa no município de Urupema, Santa Catarina. Os frutos foram beneficiados e as sementes expostas a caracterização inicial dos lotes, com determinação de teor de água, germinação e vigor e contagem e observação de sementes vazias ou predadas. As sementes de S. reitzii foram testadas quanto à melhor condição para germinação em três substratos (areia, mata-borrão e rolo de papel) e em duas temperaturas (20 e 25ºC). Diante da melhor condição de germinação, as sementes foram então submetidas a classificação fisiológica em armazenamento, realizada com secagem rápida em sílica gel até atingir aproximadamente 10% de umidade e posterior teste de germinação após a secagem. Os resultados indicaram que as sementes de S. reitzii germinam em até 11 dias, com boa germinação utilizando papel mata-borrão a 20ºC (69%) e uma taxa moderada com areia a 20 e 25ºC (55 e 57%). Não foram visualizados problemas evidentes com sementes predadas ou vazias, no entanto, as sementes foram classificadas como recalcitrantes e sensíveis à dessecação, pois perderam totalmente a viabilidade após secagem até próximo a 11% de teor de água. Essas informações permitem a melhor seleção de métodos de armazenamento e produção de mudas de S. reitzii.

Given the ecological significance and potential for afforestation and carbon sequestration of these species, this study contributes to optimizing nursery practices for successful regeneration and conservation efforts. Thus, this research assessed the physical and physiological seed quality and seedling production of Sequoia sempervirens, Sequoiadendron giganteum, and Pseudotsuga menziesii. For seed characteristics the following were tested: (I) Tetrazolium at concentrations: 0.0%, 0.1%, 0.5%, 1.0%; (II) moisture content and thousand-seed weight; (III) in-lab germination; and (IV) the classification of seeds’ viability through the use of a seed blower. Meanwhile, seedling production was tested: (I) five compositions of substrates and (II) doses of a controlled-release fertilizer (14-14-14): 0.0, 2.0, 4.0, 6.0, 8.0 g L⁻¹, for S. giganteum. The seed evaluations revealed no significant effect of tetrazolium concentrations on determining their viability. The water content results classify all species as orthodox. All species’ seeds were classified as small according to the weight of a thousand seeds. A maximum of 41% germination was observed for both S. sempervirens and S. giganteum, this value was 56% for P. menziesii, attributed to non-viability and emptiness. The seed blower increased germination by more than 20% for S. giganteum and almost 40% for P. menziesii. Seedling production was affected by the substrates, and a dosage of 4.0 g L⁻¹ of the controlled-release fertilizer is recommended for S. giganteum.

This study proposed a tetrazolium (TZ) test methodology for cataia (Drimys brasiliensis Miers) seeds and assess the efficiency of stratification in promoting development in dormant embryos. Fruits were collected in three municipalities in Santa Catarina State (SC), Brazil, the seeds extracted, and their moisture content determined. Different soaking times in the tetrazolium solution were tested and the seeds submitted to treatment with and without stratification, followed by germination testing. The TZ was performed on ungerminated seeds and the embryos were classified according to development stages. Seed moisture content ranged from 10.6 to 11.9%. The results indicated that soaking in 0.7% tetrazolium for 48 and 72 h was sufficient to assess seed viability, with the latter time facilitating assessment. Seed germination was 0 and 6% without and with stratification, respectively. Although, 94% of the unstratified seeds were viable, most of the embryos were immature; whereas, 89% of the stratified seeds were viable but only 3% mature. It was concluded that longitudinal sectioning and soaking in a 0.7% tetrazolium solution, at 25 °C in the dark for 72 h is an appropriate method for assessing the viability of cataia seeds. Stratification for 60 days did not overcome morphological dormancy.

Este trabalho teve como objetivo avaliar métodos de beneficiamento e de conservação da qualidade de sementes de Clethra scabra Pers. expostas a diferentes períodos e condições de armazenamento. Os tratamentos de beneficiamentos foram: soprador, flutuação em água e controle. As sementes foram armazenadas em geladeira e em ambiente natural de laboratório (≈ 17,4 °C; UR ≈ 83%) por 0, 90 e 150 dias, sendo posteriormente submetidas ao teste de germinação. O melhor método para beneficiar as sementes de C. scabra é pela flutuação em água, e podem ser armazenadas tanto em geladeira quanto em ambiente natural de laboratório.

Butia eriospatha (Martius ex Drude) Beccari é uma palmeira endêmica da região sul do Brasil, de valor econômico e cultural. Atualmente, a espécie está classificada como ameaçada de extinção, devido à expansão agrícola, urbanização e dificuldades de propagação da espécie. O objetivo deste trabalho foi de avaliar o efeito de fertilizantes NPK no crescimento inicial de mudas transplantadas de B. eriospatha. As mudas foram obtidas de área de regeneração natural no município de Curitibanos (SC), e transplantadas para vasos de 2,6 L contendo substrato comercial Carolina Soil®. O experimento foi conduzido em casa de vegetação, em delineamento inteiramente casualizado. Para a análise do efeito dos fertilizantes, foram utilizados sete tratamentos, sendo eles a aplicação de nitrogênio (N), fósforo (P), potássio (K), nitrogênio, fósforo e potássio (NPK), fósforo e nitrogênio (PN), nitrogênio e potássio (NK) e fósforo e potássio (PK), contendo 20 repetições cada e totalizando 140 plântulas. Os fertilizantes utilizados no experimento foram ureia, superfosfato triplo e cloreto de potássio, aplicados em períodos quinzenais. A cada bimestre foi avaliado o diâmetro de colo e altura de estipe, durante 22 meses. O melhor tratamento para o crescimento biométrico de mudas de B. eriospatha transplantadas para substrato comercial Carolina Soil® foi a associação de fósforo e nitrogênio.

Background: The primary method for propagating forest species is through seeds, which is cost-effective and ensures genetic adaptability to environmental changes. However, germination issues and genetic variability can hinder standardisation of productivity. In the case of Moquiniastrum polymorphum, a species known for its remarkable wood quality and pharmacological potential, seedling production and genetic improvement efforts have been limited. This study focused on the rescue and vegetative propagation of M. polymorphum, which are crucial steps for species selection and genetic enhancement. Methods: Protocols were tested to rescue and propagate propagules from different individuals collected in Lages, Santa Catarina (2020/2022). The vegetative rescue tests were: (I) epicormic sprouting induction through girdling techniques and detached branches; and (II) influence of individuals, disposition sense and time on the epicormic sprouting of detached branches. Vegetative propagation analyses included: (I) cutting according to individuals; and (II) relation between rooting environments and individuals on cutting. Results: The results indicated that the girdling techniques were not efficient for vegetative rescue, as only 8% of individuals produced epicormic sprouts. In contrast, detached branches showed a much higher success rate of 80% for epicormic sprouting, revealing significant differences in sprout development among individuals over time. Vertically oriented branches produced nearly three times more sprouts compared to horizontally oriented branches. Regarding vegetative propagation, certain individuals exhibited remarkable rooting rates of over 75%. However, no conclusive results were obtained when using epicormic materials or when considering different rooting environments. Conclusions: Given the significance of rescue and vegetative propagation in plant genetic improvement and the limited research addressing these aspects in M. polymorphum, this study holds substantial importance for future investigations. It is recommended to expand rescue and vegetative propagation studies to encompass additional populations, different individuals, and rooting environments, further advancing our understanding and efforts to enhance this species.

This study evaluated aspects of the pollen viability of the species Myrceugenia euosma (O. Berg) D. Legrand and Siphoneugena reitzii D. Legrand (Myrtaceae), both native trees with ornamental, medicinal and industrial potential. The study used different concentrations of sucrose to determine pollen viability in vitro and through colorimetric tests with specific dyes (Lugol, carmine acetic, and tetrazolium chloride – TTC – 0.1 and 0.05%). The two species also had their pollen stored for 30 and 90 days in freezers, refrigerators, and natural environments to check the best method for preserving their viability. The results showed that the highest average germination of M. euosma pollen was in a culture medium containing 30% sucrose. After 30 and 90 days of storage, pollen viability was significantly reduced, having preserved part of its potential only in the freezer. The pollen of S. reitzii had a higher average germination rate in a medium with 20% sucrose, but also showed a reduction in viability after 30 and 90 days of storage. The colorimetric tests showed that the pollen of both species responded to the dyes. However, the viability of Lugol and carmine acetic was considered to be overestimated in relation to the in vitro germination tests. Tetrazolium at 0.1% proved to be an alternative for checking the viability of S. reitzii pollen. It can be concluded that different concentrations of sucrose affect germination, and that storing pollen at a low temperature can preserve some of its viability in the short term.

A tetrazolium test method is proposed for evaluating seed quality of Zanthoxylum rhoifolium Lam. We used seeds from two lots, which we immersed in distilled water for 8 hours and subjected to two preparations: A - lateral incision into the seed, parallel to the hilum, to expose the endosperm, and B - extraction of the embryos. We then exposed the seeds of both preparations to the tetrazolium solution at two concentrations (0.1% and 0.05%) for two periods (24 hours and 48 hours) at a temperature of 25 ºC, then the seeds were evaluated in a 2 × 8 factorial scheme (lots × treatments) and classified in viable and non-viable. We found that the best preparation for the tetrazolium assay in Zanthoxylum rhoifolium was to remove part of the seed coat, this allowed the solution to penetrate the internal tissues without damaging the embryo. There were no significant differences between concentrations of 0.1% at 24 hours and 0.05% for 48 hours. We concluded that immersion of seeds in water for 8 hours, followed by a lateral cut parallel to the hilum exposing the endosperm at a concentration of 0.1% tetrazolium for 24 hours or 0.05% for 48 hours is an efficient method for quality assessment of Zanthoxylum rhoifolium seeds.