Snapshot of four mature quinoa (Chenopodium quinoa) seeds: a shotgun proteomics analysis with emphasis on seed maturation, reserves and early germination.

Chenopodium quinoa Willd. is a crop species domesticated over 5000 years ago. This species is highly diverse, with a geographical distribution that covers more than 5000 km from Colombia to Chile, going through a variety of edaphoclimatic conditions. Quinoa grains have great nutritional quality, raising interest at a worldwide level. In this work, by using shotgun proteomics and in silico analysis, we present an overview of mature quinoa seed proteins from a physiological context and considering the process of seed maturation and future seed germination. For this purpose, we selected grains from four contrasting quinoa cultivars (Amarilla de Maranganí, Chadmo, Sajama and Nariño) with different edaphoclimatic and geographical origins. The results give insight on the most important metabolic pathways for mature quinoa seeds including: starch synthesis, protein bodies and lipid bodies composition, reserves and their mobilization, redox homeostasis, and stress related proteins like heat-shock proteins (HSPs) and late embryogenesis abundant proteins (LEAs), as well as evidence for capped and uncapped mRNA translation. LEAs present in our analysis show a specific pattern of expression matching that of other species. Overall, this work presents a complete snapshot of quinoa seeds physiological context, providing a reference point for further studies. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01295-8.

Soybean seeds treated with zinc evaluated by X-ray micro-fluorescence spectroscopy

Zinc (Zn) is a micronutrient considered essential to plants which can be supplied through seed treatment. The treatment of soybean [Glycine max (L.) Merr.] seeds with Zn, however, is still not well known as regards the uptake and mobilization dynamics of the nutrient during the germination process. This study aimed to evaluate the uptake and distribution dynamics of Zn applied to soybean seeds at two levels of vigor during germination using X-ray micro-fluorescence spectroscopy (µ-XRF). Zinc treatments corresponded to 0, 2, 4 and 8 g of Zn per kg of seeds. High and low vigor seeds that had been treated were located appropriately so as to promote germination. Zn intensity measurements with µ-XRF were taken in different parts ("regions") of the seeds (seed coat, cotyledon, and embryonic axis) after 8, 16 and 24 h of imbibition and seedlings (primary root, hypocotyl, plumule, cotyledon, and seed coat) after 48, 72 and 96 h of germination. High vigor seeds showed higher Zn intensity in the embryonic axis in the first 16 h, while low vigor seeds showed higher intensity after 24 h. After 48, 72 and 96 h of germination low vigor seedlings showed higher Zn intensity than high vigor seedlings in the primary root. It was concluded that µ-XRF is an efficient technique for identifying variances in the dynamics of Zn uptake and mobilization during the germination of soybean seeds with different vigor levels.

Acceleration in Germination Sensu stricto Plays a Central Role on Seedling Vigor in Post-Germination.

An obvious relationship between germination sensu stricto and seedling development during post-germination has been considered, but not explained concerning vigor. Taking this into account, we used measurements of water dynamics in germinating seeds and seedling development to clarify that relationship. The biological model was soybean seeds, since it is the most relevant 'true seed' produced around world. Our findings suggest that the way energy is used (acceleration) and not its input (velocity) is the main aspect relating seed germination and seedling development, especially when considering vigor. However, velocity and acceleration can be complementary in analyses of seed physiology. Other measurements proposed here also have potential uses for testing vigor in seed lots, such as seedling vigor index and biological activity in the lot. Therefore, water dynamics in germinating seeds can be an interesting way for testing seed lots, because it is an easier, faster and cheaper method in relation to other non-destructive procedures.

The Relevance of a Physiological-Stage Approach Study of the Molecular and Environmental Factors Regulating Seed Germination in Wild Plants.

Germination represents the culmination of the seed developmental program and is affected by the conditions prevailing during seed maturation in the mother plant. During maturation, the dormancy condition and tolerance to dehydration are established. These characteristics are modulated by the environment to which they are subjected, having an important impact on wild species. In this work, a review was made of the molecular bases of the maturation, the processes of dormancy imposition and loss, as well as the germination process in different wild species with different life histories, and from diverse habitats. It is also specified which of these species present a certain type of management. The impact that the domestication process has had on certain characteristics of the seed is discussed, as well as the importance of determining physiological stages based on morphological characteristics, to face the complexities of the study of these species and preserve their genetic diversity and physiological responses.

Seed Quality and Vigor of Germination of Moringa oleífera Lam. in Saline Stress

Abstract Moringa oleifera Lam., is a tree species that has several purposes of use, standing out in the recovery of degraded areas and the use of seeds as biodsorbents in water clarification. However, ony a little is known about the behavior of seed germination under saline conditions, common in soils and water in the Brazilian Northeast. Thus, the objective was to evaluate the increment of water during the soaking and seed germination of M. oleífera that were submitted to different electrical conductivity of the irrigation water. The work was developed following a completely randomized design, with stress simulation employing saline solutions at the concentrations of 0.0; 3.0; 6.0 and 9.0 dS m-1. To determine the soaking curve, the water increment of the soaked seeds in the different saline solutions was monitored at regular intervals with four replications per treatment. To characterize the physiological quality of the seeds, the percentage, first count, speed index, average time and average germination speed were evaluated. The M. oleífera is tolerant to the effect of salinity during the germination phase, however seed vigor is reduced as a function of increased salinity. Soaking the seeds makes begin the phase II of the germination process around 10 hours and extends for up to 50 hours, when phase III begins, they absorb approximately 0.2 g of water and require 86 hours for germination. Salinity reduces the absorption and increase of water in the seeds.

Monopotassium phosphate (KH2PO4) and salicylic acid (SA) as seed priming in Vicia faba L. and Vicia sativa L. / Fosfato de monopotássio (KH2PO4) e ácido salicílico (SA) como primagem de sementes em Vicia faba L. e Vicia sativa L.

The first experiment was conducted to evaluate the impact of seed priming on germination behavior and seedling establishment in Vicia faba and Vicia sativa, for that, seeds priming was done using SA (100 µM) and KH2PO4. In order to determine the optimal concentration of KH2PO4 for improving germination, different concentrations were used: 25 µM, 50 µM, and 100 µM. The best germination behavior and seedling establishment were obtained with 25 and 50 µM KH2PO4, respectively for Vicia faba and Vicia sativa. Moreover, data showed that 100 µM of SA improved seed germination as well as the seedling establishment for both species. The second experiment was carried out to investigate the influence of seed priming for improving phosphorous (P) deficiency tolerance. To do, seedling obtained from primed and nonprimed seeds were grown in a hydroponic culture system with three different treatments: control (C, medium containing sufficient P concentration: 360 µM KH2PO4), direct phosphorus-deficient (DD, medium containing only 10 µM KH2PO4), and induced P deficiency by bicarbonate (ID, medium containing sufficient P concentration: 360 µM KH2PO4 + 0.5 g L-1 CaCO3 + 10 mM NaHCO3). Furthermore, the role of exogenous SA applied to P deficiency tolerance enhancement was explored. Seed priming or the exogenous application of SA significantly reduced the severity effect of P deficiency. In fact, the pretreated plants were observed more tolerant to P deficiency as reflected from the significant increase in plant biomass, P uptake, and an efficient antioxidant system. Overall, this paper highlights the beneficial effect of seeds priming or the exogenous application of SA in the improvement of plant tolerance to phosphorus deficiency.

A deficiência de fósforo (P) é um fator ambiental adverso comum que limita a produção agrícola em todo o mundo. Este estudo é uma avaliação do efeito benéfico da técnica de priming de sementes para tolerância à deficiência de P em Vicia faba e Vicia sativa. Para avaliar o impacto do condicionamento das sementes no comportamento germinativo de Vicia faba e Vicia sativa, suas sementes foram imersas em diferentes concentrações de KH2PO4 (25 µM, 50 µM e 100 µM) e em 100 µM de ácido salicílico (SA) por 24 h. Os resultados obtidos definiram KH2PO4 50 µM (para Vicia sativa) e KH2PO4 25 µM (para Vicia faba) como as concentrações ótimas que garantem uma melhor germinação das sementes. Além disso, os dados mostraram que a SA melhora a germinação de sementes e o estabelecimento de mudas. Posteriormente, para investigar a contribuição dessa técnica no aumento da tolerância à deficiência de P, sementes preparadas e não preparadas foram cultivadas em solução hidropônica com três tratamentos diferentes: controle (C, meio contendo concentração suficiente de P: KH2PO4 360 µM), deficiente em fósforo direto (DD, meio contendo apenas 10 µM de KH2PO4) e deficiência induzida de P por bicarbonato (ID, meio contendo concentração suficiente de P: 360 µM de KH2PO4 + 0,5 g l-1 de CaCO3 + 10 mM de NaHCO3). Além disso, o papel da SA exógeno aplicada no aumento da tolerância à deficiência de P foi explorado. A preparação das sementes ou a aplicação exógena de SA reduziu significativamente o efeito da severidade da deficiência de P. De fato, as plantas pré-tratadas foram observadas mais tolerantes à deficiência de P, refletidas no aumento significativo da biomassa da planta, na absorção de P e em um eficiente sistema antioxidante. No geral, este artigo destaca o efeito benéfico da priming de sementes ou a aplicação exógena de SA na melhoria da tolerância das plantas à deficiência de fósforo.

Vigor and tolerance of cowpea (Vigna unguiculata) genotypes under salt stress / Vigor e tolerância de genótipos de feijão-caupi (Vigna unguiculata) sob estresse salino

Saline stress is a frequent phenomenon in the arid and semi-arid regions of the globe, affecting the agricultural production of these regions, and it is necessary to use strategies that minimize the impacts of saline stress under agriculture. This requires the incorporation of species, variety and genotypes tolerant to increase agricultural production in those regions. This study aimed to evaluate germination and initial growth of cowpea genotypes under salt stress. The experimental design was completely randomized in 19 x 3 factorial scheme, composed of nineteen cowpea cultivars and three osmotic potentials, with four replicates of 50 seeds each. The germination test lasted for eight days, when the seeds were evaluated for germination percentage, germination speed index, length of shoot and root, accumulation of dry mass of shoot and root. The increase in salinity affected germination and initial growth of the cowpea genotypes. The genotypes 6 - MNCO2-689F-2-8, 10 - MNCO2-675F-4-10, 12 - MNCO3-737F-5-9, 16 - MNCO2-677F-2, 18 - BRS-Pajeú and 19 ­ Paulistinha exhibited higher tolerance to salt stress in the stage of germination and initial growth. The genotypes 11 - MNCO2-675F-9-5, 13 - BRS-Tumucumaque, 15 - MNCO3-736F-7 and 17 - BR17-Gurgueia were more susceptible to the effects of salt stress in the stage of germination and initial growth.

O estresse salino é um fenômeno frequente em regiões áridas e semiáridas do globo, afetando a produção agrícola dessas regiões, sendo necessário lançar mão de estratégias que minimizem os impactos do estresse salino sob agricultura, para isso é necessário a incorporação de espécies, variedade e genótipos tolerantes para aumentar a produção nessas regiões. Assim, objetivou-se com esse trabalho avaliar a germinação e o crescimento inicial de genótipos de feijão-caupi sob estresse salino. Utilizou-se de um delineamento experimental inteiramente casualizado em esquema fatorial 19 x 3, constituído de dezenove cultivares de feijão-caupi e três potenciais osmóticos, com quatro repetições de 50 sementes cada. O teste de germinação teve duração de oito dias, quando as sementes foram avaliadas a quanto à percentagem de germinação, índice de velocidade de germinação, comprimento da parte aérea e da raiz, acúmulo de massa seca da parte aérea e da raiz. O aumento da salinidade afetou a germinação e o crescimento inicial dos genótipos de feijãocaupi. Os genótipos 6 - MNCO2-689F-2-8, 10 - MNCO2-675F-4-10, 12 - MNCO3-737F-5-9; 16 - MNCO2-677F-2; 18 - BRS-Pajeú e 19 ­ Paulistinha apresentaram maior tolerância ao estresse salino na fase de germinação e crescimento inicial. Os genótipos 11 - MNCO2-675F-9-5, 13 - BRS-Tumucumaque; 15 - MNCO3-736F-7 e 17 - BR17-Gurgueia foram mais suscetíveis aos efeitos do estresse salino na fase de germinação e crescimento inicial

Seed vigor testing: an overview of the past, present and future perspective

The assessment of seed vigor has many important implications to the seed industry as a basic monitoring of seed physiological potential during different phases of seed production and a support for strategic decisions regarding the selection of high quality seedlots to meet the consumer demand. The potential attributes of seed vigor as a fundamental physiological seed characteristic and its association with field stand establishment and crop productivity has been worldwide recognized from the 1960s onward. This led to the diversification of research approaches involving the synchronization of different physiological characteristics and events that determine the potential for high performance during seed storage and after sowing. The basic objective of vigor testing is to provide a consistent identification of differences in physiological potential among seedlots of commercial value and this represents a more sensitive parameter than the germination test. There are various procedures to assess seed vigor including those that directly or indirectly evaluate seed metabolic state or identify seed tolerance to specific stress(es). At the same time, in more recent years, new knowledge has come from molecular biology, biotechnology, biophysics and seed and seedling imaging analyses; these approaches has been important complements to traditional seed research.. This text has the purpose to emphasize the role of Brazilian research in seed vigor, whose competence is internationally recognized, and to provide an overview of the evolution of knowledge also attempting to highlight events that contributed to the advancement of research on the subject.

Seed vigor testing: an overview of the past, present and future perspective

The assessment of seed vigor has many important implications to the seed industry as a basic monitoring of seed physiological potential during different phases of seed production and a support for strategic decisions regarding the selection of high quality seedlots to meet the consumer demand. The potential attributes of seed vigor as a fundamental physiological seed characteristic and its association with field stand establishment and crop productivity has been worldwide recognized from the 1960s onward. This led to the diversification of research approaches involving the synchronization of different physiological characteristics and events that determine the potential for high performance during seed storage and after sowing. The basic objective of vigor testing is to provide a consistent identification of differences in physiological potential among seedlots of commercial value and this represents a more sensitive parameter than the germination test. There are various procedures to assess seed vigor including those that directly or indirectly evaluate seed metabolic state or identify seed tolerance to specific stress(es). At the same time, in more recent years, new knowledge has come from molecular biology, biotechnology, biophysics and seed and seedling imaging analyses; these approaches has been important complements to traditional seed research.. This text has the purpose to emphasize the role of Brazilian research in seed vigor, whose competence is internationally recognized, and to provide an overview of the evolution of knowledge also attempting to highlight events that contributed to the advancement of research on the subject.(AU)

Ação inibitória do endosperma na germinação in vitro de embrião zigótico de pinhão manso / Inhibitory action of endosperm on in vitro germination of physic nut zygotic embryo

A busca por protocolos de micropropagação de pinhão manso tem resultado em relatos sobre dificuldades na germinação in vitro de sementes recém colhidas. Nesse sentido, levantou-se a hipótese da dormência estar relacionada com a presença do endosperma. Objetivando investigar a influência do endosperma no desenvolvimento in vitro de embriões zigóticos de pinhão manso, extratos puros e filtrados de endosperma de sementes recém colhidas e armazenadas por 50 e 100 dias foram adicionados ao meio MS, no qual foram colocados embriões zigóticos isolados ou contendo endosperma. Foi possível observar que a presença do endosperma junto ao embrião exerce uma inibição à retomada do desenvolvimento do embrião. Ademais, a adição de extratos do endosperma no meio de cultivo reduziu sobremaneira o desenvolvimento dos embriões, evidenciando que além de provável inibição física, o endosperma pode contribuir com inibidores químicos no processo de germinação. Essas observações estão baseadas no perfeito desenvolvimento dos embriões, quando estes foram adicionados isolados ao meio MS, desprovido do extrato.

Researches on physic nut micropropagation have resulted in reports about difficulties in the process of in vitro germination of fresh seeds, and we hypothesized that this dormancy is related to endosperm presence. Aiming to investigate the influence of the endosperm presence on in vitro development of zygotic embryos of physic nut, pure and filtered extracts of the endosperm of newly harvested and stored seeds for up to 100 days were added to MS medium, in which zygotic embryos were added alone or attached to the endosperm. It was observed that the endosperm presence attached to the embryo seems to establish dormancy to the restart of the embryo development. Moreover, addition of endosperm extracts into the MS medium greatly reduced the embryos development, supporting the idea that in addition to probable inhibition physics, the endosperm may contribute to chemical inhibitors in the germination process. All these idea were supported by perfect embryo development when it was added to MS medium without endosperm structure or extract.

Ação inibitória do endosperma na germinação in vitro de embrião zigótico de pinhão manso / Inhibitory action of endosperm on in vitro germination of physic nut zygotic embryo

A busca por protocolos de micropropagação de pinhão manso tem resultado em relatos sobre dificuldades na germinação in vitro de sementes recém colhidas. Nesse sentido, levantou-se a hipótese da dormência estar relacionada com a presença do endosperma. Objetivando investigar a influência do endosperma no desenvolvimento in vitro de embriões zigóticos de pinhão manso, extratos puros e filtrados de endosperma de sementes recém colhidas e armazenadas por 50 e 100 dias foram adicionados ao meio MS, no qual foram colocados embriões zigóticos isolados ou contendo endosperma. Foi possível observar que a presença do endosperma junto ao embrião exerce uma inibição à retomada do desenvolvimento do embrião. Ademais, a adição de extratos do endosperma no meio de cultivo reduziu sobremaneira o desenvolvimento dos embriões, evidenciando que além de provável inibição física, o endosperma pode contribuir com inibidores químicos no processo de germinação. Essas observações estão baseadas no perfeito desenvolvimento dos embriões, quando estes foram adicionados isolados ao meio MS, desprovido do extrato.(AU)

Researches on physic nut micropropagation have resulted in reports about difficulties in the process of in vitro germination of fresh seeds, and we hypothesized that this dormancy is related to endosperm presence. Aiming to investigate the influence of the endosperm presence on in vitro development of zygotic embryos of physic nut, pure and filtered extracts of the endosperm of newly harvested and stored seeds for up to 100 days were added to MS medium, in which zygotic embryos were added alone or attached to the endosperm. It was observed that the endosperm presence attached to the embryo seems to establish dormancy to the restart of the embryo development. Moreover, addition of endosperm extracts into the MS medium greatly reduced the embryos development, supporting the idea that in addition to probable inhibition physics, the endosperm may contribute to chemical inhibitors in the germination process. All these idea were supported by perfect embryo development when it was added to MS medium without endosperm structure or extract.(AU)

Conservação pós-colheita de pinhões [sementes de Araucaria angustifolia (Bertoloni) Otto Kuntze] armazenados em diferentes temperaturas

The seeds ('pinhões') of Brazilian pine (Araucaria angustifolia) represent an important sorce of income to the rural comunities and also an additional food product to be offered to the tourists and population in Southern Brazil. Temperature and humidity in the storage environment are the mais factors affecting 'pinhões' postharvest preservation. This work was carried out to evaluate the effects of storage temperature on postharvest respiration and ethylene production, as well as on fresh mass loss and germination of 'pinhões' intended for human consumption. The experiment followed a completely randomized design with six storage temperatures (2, 10, 20, 30, 40, and 50°C) and four replicates, each replicate with about 300g of 'pinhões'. 'Pinhões' stored at the different temperatures did not exhibit ethylene production (at levels detectable by gas chromatography, with a sensibility of 1ppm). The respiratory rates increased substancialy in the range from 2°C to 37.1°C, with a Q10 FONT FACE=Symbol>@ /FONT> 2.5. The respiration decreased substantialy by increasing the temperature from 37.1°C to 50°C. The higher germination rate was achieved for 'pinhões' stored at 20°C (~55% germination after 26 days storage). The germination reduced for 'pinhões' stored at temperatures lower (~1% and 21% of germination for 'pinhões' left at 2 and 10°C, respectively) or higher (9% and 1% of germination for 'pinhões' left at 30°C and 40-50°C, respectively) than 20°C. These results show the importance of 'pinhões' storage at temperatures close to 0°C to reduce the metabolic ativity, especially the respiration, and, therefore, to preserve the product quality and to reduce fresh mass loss and seed germination.

O pinhão (semente de Araucaria angustifolia) representa importante fonte de renda aos produtores rurais e uma opção a mais de alimento característico a ser oferecido aos turistas e à população em geral na região Sul do Brasil. A temperatura e a umidade de armazenamento são os principais determinantes da preservação pós-colheita de pinhões. Este trabalho objetivou avaliar os efeitos da temperatura de armazenamento nas taxas respiratórias e de evolução de etileno, bem como na perda de massa fresca e na germinação pós-colheita de pinhões destinados para consumo alimentar humano. Seguiu-se o delineamento experimental inteiramente casualizado com seis temperaturas de armazenamento (2, 10, 20, 30, 40 e 50°C) e quatro repetições, cada repetição correspondendo a amostras contendo cerca de 300g de pinhões. Pinhões armazenados nas diferentes temperaturas não apresentaram produção de etileno (em níveis detectáveis através de cromatografia gasosa, com sensibilidade de 1ppm). A taxa respiratória aumentou substancialmente com o aumento na temperatura, com um Q10 FONT FACE=Symbol>@ /FONT> 2,5 na faixa de temperatura de 2 a 37,1°C. Houve redução substancial da respiração com o aumento na temperatura de 37,1 para 50°C. A maior germinação dos pinhões foi verificada na temperatura de 20°C (~55% dos pinhões germinados aos 26 dias de armazenamento), reduzindo em temperaturas menores (~1% e 21% de germinação nas temperaturas de 2 e 10°C, respectivamente) ou maiores (9% e 1% de germinação nas temperaturas de 30°C e 40-50°C, respectivamente). Estes resultados demonstram a importância do resfriamento de pinhões para temperaturas próximas a 0°C, visando a reduzir a atividade metabólica, especialmente a respiração, com vistas à preservação de sua qualidade e à redução na perda de massa fresca e na germinação pós-colheita.

Conservação pós-colheita de pinhões [sementes de Araucaria angustifolia (Bertoloni) Otto Kuntze] armazenados em diferentes temperaturas

The seeds ('pinhões') of Brazilian pine (Araucaria angustifolia) represent an important sorce of income to the rural comunities and also an additional food product to be offered to the tourists and population in Southern Brazil. Temperature and humidity in the storage environment are the mais factors affecting 'pinhões' postharvest preservation. This work was carried out to evaluate the effects of storage temperature on postharvest respiration and ethylene production, as well as on fresh mass loss and germination of 'pinhões' intended for human consumption. The experiment followed a completely randomized design with six storage temperatures (2, 10, 20, 30, 40, and 50°C) and four replicates, each replicate with about 300g of 'pinhões'. 'Pinhões' stored at the different temperatures did not exhibit ethylene production (at levels detectable by gas chromatography, with a sensibility of 1ppm). The respiratory rates increased substancialy in the range from 2°C to 37.1°C, with a Q10 FONT FACE=Symbol>@ /FONT> 2.5. The respiration decreased substantialy by increasing the temperature from 37.1°C to 50°C. The higher germination rate was achieved for 'pinhões' stored at 20°C (~55% germination after 26 days storage). The germination reduced for 'pinhões' stored at temperatures lower (~1% and 21% of germination for 'pinhões' left at 2 and 10°C, respectively) or higher (9% and 1% of germination for 'pinhões' left at 30°C and 40-50°C, respectively) than 20°C. These results show the importance of 'pinhões' storage at temperatures close to 0°C to reduce the metabolic ativity, especially the respiration, and, therefore, to preserve the product quality and to reduce fresh mass loss and seed germination.

O pinhão (semente de Araucaria angustifolia) representa importante fonte de renda aos produtores rurais e uma opção a mais de alimento característico a ser oferecido aos turistas e à população em geral na região Sul do Brasil. A temperatura e a umidade de armazenamento são os principais determinantes da preservação pós-colheita de pinhões. Este trabalho objetivou avaliar os efeitos da temperatura de armazenamento nas taxas respiratórias e de evolução de etileno, bem como na perda de massa fresca e na germinação pós-colheita de pinhões destinados para consumo alimentar humano. Seguiu-se o delineamento experimental inteiramente casualizado com seis temperaturas de armazenamento (2, 10, 20, 30, 40 e 50°C) e quatro repetições, cada repetição correspondendo a amostras contendo cerca de 300g de pinhões. Pinhões armazenados nas diferentes temperaturas não apresentaram produção de etileno (em níveis detectáveis através de cromatografia gasosa, com sensibilidade de 1ppm). A taxa respiratória aumentou substancialmente com o aumento na temperatura, com um Q10 FONT FACE=Symbol>@ /FONT> 2,5 na faixa de temperatura de 2 a 37,1°C. Houve redução substancial da respiração com o aumento na temperatura de 37,1 para 50°C. A maior germinação dos pinhões foi verificada na temperatura de 20°C (~55% dos pinhões germinados aos 26 dias de armazenamento), reduzindo em temperaturas menores (~1% e 21% de germinação nas temperaturas de 2 e 10°C, respectivamente) ou maiores (9% e 1% de germinação nas temperaturas de 30°C e 40-50°C, respectivamente). Estes resultados demonstram a importância do resfriamento de pinhões para temperaturas próximas a 0°C, visando a reduzir a atividade metabólica, especialmente a respiração, com vistas à preservação de sua qualidade e à redução na perda de massa fresca e na germinação pós-colheita.

Viabilidade e superação da dormência em sementes de Araçá-boi (Eugenia stipitata ssp. sororia)

Eugenia stipitata ssp. sororia McVaugh - Myrtaceae is a small Amazonian fruit tree with considerable economic potential. The present work investigated the effects of dehydration on seed viability and evaluated methods of overcoming seed dormancy by mechanical scarification (by peeling and sanding). The physiological quality of seeds is affected by reduction in moisture content. Seeds show recalcitrant behaviour with a critical moisture content between 58,8 and 47,1 %. No seeds survived dehydration to moisture contents of less than or equal to 25,76%. In view of the detrimental effects of drying, seeds should preferably be sown immediately after being extracted and cleaned. The seed integument offers mechanical resistance to expansion of the embryo. Total removal of the integument proved to be the most efficient method of overcoming dormancy since it eliminates resistance in the region where the embryo normally breaks through. The average time for emergence was 66 days and the final percentage emergence was 96%. Simple abrasion of the integument caused mechanical injury to the seeds with adverse consequences on emergence and vigour.

O araçá-boi (Eugenia stipitata ssp. sororia McVaugh - Myrtaceae) é uma frutífera amazônica com potencial agroindustrial. O presente trabalho verificou os efeitos da desidratação sobre a viabilidade de sementes e avaliou métodos de escarificação mecânica (por descascamento e lixamento) na superação da dormência de sementes dessa espécie. A qualidade fisiológica das sementes é afetada pela redução do teor de água. As sementes apresentam comportamento recalcitrante, sendo que o nível crítico de umidade pode estar situado entre 58,8 e 47,1%. A desidratação a níveis iguais ou inferiores a 25,76% de água provocou a morte em 100% das sementes. As sementes devem ser semeadas, preferencialmente, logo após a extração e limpeza. O tegumento das sementes apresenta resistência mecânica à expansão do embrião. A remoção total do tegumento foi o método mais eficiente na superação da dormência, pois elimina a resistência na região onde ocorrerá a ruptura pelo embrião, com tempo médio de emergência de 66 dias e percentagem final de emergência de 96%. Os lixamentos provocaram injúrias mecânicas nas sementes, tendo consequências diretas na emergência e vigor.

Viabilidade e superação da dormência em sementes de Araçá-boi (Eugenia stipitata ssp. sororia)

Eugenia stipitata ssp. sororia McVaugh - Myrtaceae is a small Amazonian fruit tree with considerable economic potential. The present work investigated the effects of dehydration on seed viability and evaluated methods of overcoming seed dormancy by mechanical scarification (by peeling and sanding). The physiological quality of seeds is affected by reduction in moisture content. Seeds show recalcitrant behaviour with a critical moisture content between 58,8 and 47,1 %. No seeds survived dehydration to moisture contents of less than or equal to 25,76%. In view of the detrimental effects of drying, seeds should preferably be sown immediately after being extracted and cleaned. The seed integument offers mechanical resistance to expansion of the embryo. Total removal of the integument proved to be the most efficient method of overcoming dormancy since it eliminates resistance in the region where the embryo normally breaks through. The average time for emergence was 66 days and the final percentage emergence was 96%. Simple abrasion of the integument caused mechanical injury to the seeds with adverse consequences on emergence and vigour.

O araçá-boi (Eugenia stipitata ssp. sororia McVaugh - Myrtaceae) é uma frutífera amazônica com potencial agroindustrial. O presente trabalho verificou os efeitos da desidratação sobre a viabilidade de sementes e avaliou métodos de escarificação mecânica (por descascamento e lixamento) na superação da dormência de sementes dessa espécie. A qualidade fisiológica das sementes é afetada pela redução do teor de água. As sementes apresentam comportamento recalcitrante, sendo que o nível crítico de umidade pode estar situado entre 58,8 e 47,1%. A desidratação a níveis iguais ou inferiores a 25,76% de água provocou a morte em 100% das sementes. As sementes devem ser semeadas, preferencialmente, logo após a extração e limpeza. O tegumento das sementes apresenta resistência mecânica à expansão do embrião. A remoção total do tegumento foi o método mais eficiente na superação da dormência, pois elimina a resistência na região onde ocorrerá a ruptura pelo embrião, com tempo médio de emergência de 66 dias e percentagem final de emergência de 96%. Os lixamentos provocaram injúrias mecânicas nas sementes, tendo consequências diretas na emergência e vigor.

SANIDADE DE SEMENTES DE FEIJÃO NO ESTADO DE SANTA CATARINA - RESULTADOS PRELIMINARES

It was collected 212 samples of common bean (Phaseolus vulgaris L.) seeds during 1985/86 in seven producers localities of Santa Catarina State. The samples were categorized in three ways: place of sample, production origin and cultivars. It was done determinations about seed physiology and seed pathology. Only Colletotrichum lindemuthianum, Fusarium spp, Rhizoctonia solani and storage fungi (Aspergillus spp and Penicillum spp) were considered. It was possible to obtain differences between sample categories in respect of field pathogens and harvest, drying and storage.

Na safra de 1985/86 foram coletadas 212 amostras de sementes de feijão (Phaseolus vulgaris L.) em sete municípios produtores do Estado de Santa Catarina As amostras foram categorizadas segundo locais de coleta, origem de produção e cultivares. Foram realizadas determinações de patologia de sementes, poder germinativo e vigor. Levou-se em consideração apenas a ocorrência de Colletotrichum lindemuthianum, Fusarium spp, Rhizoctoni solani e fungos de armazenamento (Aspergillus spp e Penicillium spp). Considerado as variáveis medidas, foi possível distinguir diferenças entre as diversas categorias de amostras no tocante à presença de patógenos de campo e condições de colheita, secagem e armazenamento.

Sanidade de sementes de feijão no estado de santa catarina - resultados preliminares

It was collected 212 samples of common bean (Phaseolus vulgaris L.) seeds during 1985/86 in seven producers localities of Santa Catarina State. The samples were categorized in three ways: place of sample, production origin and cultivars. It was done determinations about seed physiology and seed pathology. Only Colletotrichum lindemuthianum, Fusarium spp, Rhizoctonia solani and storage fungi (Aspergillus spp and Penicillum spp) were considered. It was possible to obtain differences between sample categories in respect of field pathogens and harvest, drying and storage.

Na safra de 1985/86 foram coletadas 212 amostras de sementes de feijão (Phaseolus vulgaris L.) em sete municípios produtores do Estado de Santa Catarina As amostras foram categorizadas segundo locais de coleta, origem de produção e cultivares. Foram realizadas determinações de patologia de sementes, poder germinativo e vigor. Levou-se em consideração apenas a ocorrência de Colletotrichum lindemuthianum, Fusarium spp, Rhizoctoni solani e fungos de armazenamento (Aspergillus spp e Penicillium spp). Considerado as variáveis medidas, foi possível distinguir diferenças entre as diversas categorias de amostras no tocante à presença de patógenos de campo e condições de colheita, secagem e armazenamento.