Seed functional ecology in Brazilian rock outcrop vegetation: an integrative synthesis.

BACKGROUND AND AIMS: Rock outcrop vegetation is distributed worldwide and hosts a diverse and unique flora that evolved under harsh environmental conditions. Unfortunately, seed ecology in such ecosystems has received little attention, especially regarding seed traits, germination responses to abiotic factors and the potential role of phylogenetic relatedness on such features Here, we provide the first quantitative and phylogenetically-informed synthesis of the seed functional ecology of Brazilian rock outcrop vegetation, with a particular focus on quartzitic and ironstone campo rupestre. METHODS: Using a database of functional trait data, we calculated the phylogenetic signal of seven seed traits for 371 taxa and tested whether they varied among growth forms, geographic distribution, and microhabitats. We also conducted meta-analyses that included 4,252 germination records for 102 taxa to assess the effects of light, temperature, and fire-related cues on the germination of campo rupestre species and explored how the aforementioned ecological groups and seed traits modulate germination responses. KEY RESULTS: All traits and germination responses showed a moderate-to-strong phylogenetic signal. Campo rupestre species responded positively to light and had maximum germination between 20-25 ºC. The effect of temperatures beyond this range was moderated by growth form, species geographic distribution, and microhabitat. Seeds exposed to heat shocks above 80 °C lost viability, but smoke accelerated germination. We found a moderating effect of seed mass for in responses to light and heat shocks, with larger, dormant seeds tolerating heat better but less sensitive to light. Species from xeric habitats evolved phenological strategies to synchronise germination during periods of increased soil water availability. CONCLUSIONS: Phylogenetic relatedness plays a major role in shaping seed ecology of Brazilian rock outcrop vegetation. Nevertheless, seed traits and germination responses varied significantly between growth forms, species geographic distribution and microhabitats, providing support to the regeneration niche hypothesis and the role of functional traits in shaping germination in these ecosystems.

Shotgun proteomics profiling of chia seeds (Salvia hispanica L.) reveals genotypic differential responses to viability loss.

Introduction: Exposure to elevated temperatures and relative humidity expedites the seed aging process, finally leading to seed viability loss. In this context, certain proteins play a pivotal role in safeguarding the longevity of seeds. However, the seedproteomic response to loss viability in Salvia hispanica L., commonly known as chia, remains incompletely understood. Methods: This work explores the application of proteomics as a potent tool for uncovering molecular responses to viability loss caused by artificial aging in two chia genotypes, WN and MN. Results: By using a quantitative label-free proteomics analysis (LC-MS/MS), 1787 proteins wereidentified in chia seeds at a 95% confidence level, including storage proteins, heat shock proteins (HSPs), late embryogenesis abundant proteins (LEA),oleosins, reactive oxygen species (ROS)-related enzymes, and ribosomal proteins. A relatively low percentage of exclusive proteins were identified in viable and non-viable seeds. However, proteins exhibiting differential abundancebetween samples indicated variations in the genotype and physiological status. Specifically, the WN genotype showed 130 proteins with differential abundancecomparing viable and non-viable seeds, while MN displayed changes in the abundance of 174 proteins. While both showed a significant decrease in keyproteins responsible for maintaining seed functionality, longevity, and vigor withhigh-temperature and humidity conditions, such as LEA proteins or HSPs, ROS, and oleosins, distinct responses between genotypes were noted, particularly in ribosomal proteins that were accumulated in MN and diminished in WN seeds. Discussion: Overall, the results emphasize the importance of evaluating changes in proteins of viable and non-viable seeds as they offer valuable insights into the underlying biological mechanisms responsible for the maintenance of chia seed integrity throughout high-temperature and humidity exposure.

Flavonoids and their relationship with the physiological quality of seeds from different soybean genotypes.

Flavonoids are compounds that result from the secondary metabolism of plants and play a crucial role in plant development and mitigating biotic and abiotic stresses. The highest levels of flavonoids are found in legumes such as soybean. Breeding programs aim to increase desirable traits, such as higher flavonoid contents and vigorous seeds. Soybeans are one of the richest sources of protein in the plant kingdom and the main source of flavonoid derivatives for human health. In view of this, the hypothesis of this study is based on the possibility that the concentration of isoflavones in soybean seeds contributes to the physiological quality of the seeds. The aim of this study was to analyze the content of flavonoids in soybean genotypes and their influence on the physiological quality of the seeds. Seeds from thirty-two soybean genotypes were obtained by carrying out a field experiment during the 2021/22 crop season. The experimental design was randomized blocks with four replications and thirty-two F3 soybean populations. The seeds obtained were subjected to germination, first germination counting, electrical conductivity and tetrazolium vigor and viability tests. After drying and milling the material from each genotype, liquid chromatography analysis was carried out to obtain flavonoids, performed at UPLC level. Data were submitted to analysis of variance and, when significant, the means were compared using the Scott-Knott test at 5% probability. The results found here show the occurrence of genotypes with higher amounts of flavonoids when compared to their peers. The flavonoid FLVD_G2 had the highest concentration and differed from the others. Thus, we can assume that the type and concentration of flavonoids does not influence the physiological quality of seeds from different soybean genotypes, but it does indirectly contribute to viability and vigor, since the genotypes with the highest FLVD_G2 levels had better FGC values. The findings indicate that there is a difference between the content of flavonoids in soybean genotypes, with a higher content of genistein. The content of flavonoids does not influence the physiological quality of seeds, but contributes to increasing viability and vigor.

Rock n' Seeds: A database of seed functional traits and germination experiments from Brazilian rock outcrop vegetation.

Advancing functional ecology depends fundamentally on the availability of data on reproductive traits, including those from tropical plants, which have been historically underrepresented in global trait databases. Although some valuable databases have been created recently, they are mainly restricted to temperate areas and vegetative traits such as leaf and wood traits. Here, we present Rock n' Seeds, a database of seed functional traits and germination experiments from Brazilian rock outcrop vegetation, recognized as outstanding centers of diversity and endemism. Data were compiled through a systematic literature search, resulting in 103 publications from which seed functional traits were extracted. The database includes information on 16 functional traits for 383 taxa from 148 genera, 50 families, and 25 orders. These 16 traits include two dispersal, six production, four morphological, two biophysical, and two germination traits-the major axes of the seed ecological spectrum. The database also provides raw data for 48 germination experiments, for a total of 10,187 records for 281 taxa. Germination experiments in the database assessed the effect of a wide range of abiotic and biotic factors on germination and different dormancy-breaking treatments. Notably, 8255 of these records include daily germination counts. This input will facilitate synthesizing germination data and using this database for a myriad of ecological questions. Given the variety of seed traits and the extensive germination information made available by this database, we expect it to be a valuable resource advancing comparative functional ecology and guiding seed-based restoration and biodiversity conservation in tropical megadiverse ecosystems. There are no copyright restrictions on the data; please cite this paper when using the current data in publications; also the authors would appreciate notification of how the data are used in publications.

O avanço da ecologia funcional depende fundamentalmente da disponibilidade de dados sobre traços reprodutivos, incluindo dados de plantas tropicais, que têm sido historicamente subrepresentados em bancos de dados de traços funcionais globais. Embora alguns bancos de dados valiosos tenham sido criados recentemente, eles são restritos principalmente a áreas temperadas e a traços vegetativos, como traços de folhas e madeira. Neste artigo apresentamos Rock n' Seeds, um banco de dados de traços funcionais de sementes e experimentos de germinação de vegetações associadas a afloramentos rochosos do Brasil, os quais são reconhecidos como centros notáveis de diversidade e endemismo. Os dados foram compilados através de uma revisão sistemática na literatura, resultando em 103 publicações das quais foram extraídos os traços funcionais das sementes. O banco de dados inclui informações de 16 traços funcionais para 383 taxa de 148 gêneros, 50 famílias e 25 ordens. Estes dezesseis traços incluem dois traços de dispersão, seis de produção, quatro morfológicos, dois biofísicos e dois germinativos; os eixos principais do espectro ecológico da semente. O banco de dados também fornece os dados brutos para 48 experimentos de germinação para um total de 10.187 registros para 281 taxa. Os experimentos de germinação no banco de dados avaliaram o efeito de uma ampla gama de fatores abióticos e bióticos sobre a germinação e diferentes tratamentos de quebra de dormência. Particularmente, 8.255 desses registros incluem a contagem diária da germinação. Estas informações facilitarão a síntese de dados de germinação e a utilização deste banco de dados para uma grande variedade de questões ecológicas. Dada a variedade de traços das sementes e as amplas informações sobre germinação disponibilizadas por este banco de dados, esperamos que ele seja um recurso valioso para o avanço da ecologia funcional comparativa e para orientar a restauração baseada em sementes e a conservação da biodiversidade em ecossistemas tropicais megadiversos. Não há restrições de direitos autorais sobre os dados; favor citar este artigo ao utilizar os dados nas publicações e os autores agradeceriam uma notificação de como os dados são utilizados nas publicações.

El avance de la ecología funcional depende fundamentalmente de la disponibilidad de datos sobre rasgos reproductivos-incluyendo los de las plantas tropicales-los cuales han estado poco representados en las bases de datos globales de rasgos. Aunque recientemente se han creado algunas bases de datos valiosas, estas se encuentran restringidas principalmente a las zonas templadas y a los rasgos vegetativos, como los de las hojas y la madera. En este artículo presentamos Rock n' Seeds, una base de datos de rasgos funcionales de semillas y experimentos de germinación de la vegetación asociada a afloramientos rocosos de Brasil, los cuales son destacados centros de diversidad y endemismo. Los datos se recopilaron mediante una búsqueda bibliográfica sistemática, que dio como resultado 103 publicaciones de las que se extrajeron los rasgos funcionales de las semillas. La base de datos incluye información de dieciséis rasgos funcionales para 383 taxones de 148 géneros, 50 familias y 25 órdenes. Estos rasgos incluyen dos rasgos de dispersión, seis de producción, cuatro morfológicos, dos biofísicos y dos de germinación; siendo estos los principales ejes del espectro ecológico de las semillas. La base de datos también proporciona los datos brutos de 48 experimentos de germinación, para un total de 10.187 registros de 281 taxones. Dichos experimentos de germinación evaluaron el efecto de una amplia gama de factores abióticos y bióticos sobre la germinación y de diferentes tratamientos para romper la dormancia. En particular, 8.255 de estos registros cuentan con conteos diarios de germinación. Esto facilitará la síntesis de los datos de germinación y el uso de esta base de datos para una gran diversidad de preguntas ecológicas. Dada la variedad de rasgos de las semillas y la amplia información sobre germinación que ofrece esta base de datos, esperamos que sea un recurso valioso para el avance de la ecología funcional comparativa y para orientar la restauración basada en semillas y la conservación de la biodiversidad en ecosistemas tropicales megadiversos. No hay restricciones de derechos de autor sobre los datos; se solicita citar este documento cuando se utilicen los datos en publicaciones y los autores agradecerán ser notificados sobre cómo se utilizan los datos en las publicaciones.

Seed longevity of maize conserved under germplasm bank conditions for up to 60 years.

BACKGROUND AND AIMS: The long-term conservation of seeds of plant genetic resources is of key importance for food security and preservation of agrobiodiversity. Nevertheless, there is scarce information available about seed longevity of many crops under germplasm bank conditions. METHODS: Through germination experiments as well as the analysis of historical monitoring data, we studied the decline in viability manifested by 1000 maize (Zea mays subsp. mays) seed accessions conserved for an average of 48 years at the CIMMYT germplasm bank, the largest maize seedbank in the world, under two cold storage conditions: an active (-3 °C; intended for seed distribution) and a base conservation chamber (-15 °C; for long-term conservation). KEY RESULTS: Seed lots stored in the active chamber had a significantly lower and more variable seed germination, averaging 81.4 %, as compared with the seed lots conserved in the base chamber, averaging 92.1 %. The average seed viability detected in this study was higher in comparison with that found in other seed longevity studies on maize conserved under similar conditions. A significant difference was detected in seed germination and longevity estimates (e.g. p85 and p50) among accessions. Correlating seed longevity with seed traits and passport data, grain type showed the strongest correlation, with flint varieties being longer lived than floury and dent types. CONCLUSIONS: The more rapid loss of seed viability detected in the active chamber suggests that the seed conservation approach, based on the storage of the same seed accessions in two chambers with different temperatures, might be counterproductive for overall long-term conservation and that base conditions should be applied in both. The significant differences detected in seed longevity among accessions underscores that different viability monitoring and regeneration intervals should be applied to groups of accessions showing different longevity profiles.

Germinación de semillas de Crescentia alata (Bignoniaceae) en distintas condiciones de temperatura, luminosidad y almacenamiento

Crescentia alata (Bignoniaceae) es una especie arborescente de gran interés cultural y económico desde México hasta Costa Rica. Sin embargo, la protección de las poblaciones naturales y el establecimiento de plantaciones son limitados por la carencia de información sobre germinación de semillas y crecimiento de plántulas. Este estudio pretende caracterizar los frutos y las semillas, evaluar el proceso de germinación a diferentes temperaturas y niveles de luminosidad, y determinar las condiciones óptimas de temperatura, humedad y almacenamiento para mantener viables las semillas. Se midieron altura, diámetro y masa de frutos, así como largo, ancho y masa de semillas; además, se contó el número de semillas por fruto. Asimismo, se evaluó el porcentaje de germinación a cinco temperaturas (15, 20, 30, 20-30 y 25-30 °C), en condiciones de luz-oscuridad, con almacenamiento a tres temperaturas (5° C, 15 °C y ambiente: 22-24 °C) durante 36 meses. También se observó la viabilidad de las semillas conservadas dentro del fruto. El valor promedio del índice de redondez (IR) fue -1.86; esto indica que los frutos son redondeado-achatados. En promedio el fruto midió 7.90 ± 2.58 cm de altura y 9.62 ± 1.21 cm de diámetro; las semillas midieron 0.75 ± 0.07 cm de largo y 0.67 ± 0.05 cm de ancho. La masa promedio del fruto fue 414.57 g y cada fruto tuvo en promedio ca. 691 semillas, que no germinaron a 15 °C ni a 20 °C; en la oscuridad disminuyó la germinación y la viabilidad de las semillas se redujo cuando se almacenaron a temperatura ambiente (22-24 °C) y cuando permanecieron dentro del fruto. Los resultados indican que las semillas de C. alata germinan mejor a 30 °C, en condiciones de luz y separadas de la pulpa del fruto antes de almacenarse; además, almacenadas a temperaturas bajas (5 °C y 15 °C) los porcentajes de germinación y la viabilidad se mantienen altos (ca. 90 %) hasta por tres años. Estos datos pueden contribuir a mejorar el almacenamiento de semillas y la obtención de plántulas para propagación; así podría aumentar el tamaño de las poblaciones con fines económicos o de conservación, lo que favorecería tanto a la especie estudiada como al bosque tropical seco en que habita.

Crescentia alata is a natural resource with cultural and economic value from Mexico to Costa Rica. Nevertheless, protection of natural populations and establishment of plantations are limited by lack of information on seed germination and plant growth. This study aims to characterize size, weight and number of fruits and seeds, to evaluate the seed germination process at different temperatures and light conditions, and to determine the optimal conditions of temperature, humidity, and storage periods for viable seeds. We measured germination at five different temperatures (15, 20, 30, 20-30, and 25-30 °C), in light-dark conditions, with seed storage at three temperatures (5 °C, 15 °C, and ambient temperature: 22-24 °C) during 36 months. Mean values: fruit roundness index -1.86 (i.e. they are flattened-rounded). Fruit height 7.90 ± 2.58 cm, diameter 9.62 ± 1.21 cm; seeds were 0.75 ± 0.07 cm long and 0.67 ± 0.05 cm wide. Fruit mass 414.57 g; each fruit contained on average ca. 691 seeds. Seeds did not germinate at 15 °C or 20 °C; germination decreased in darkness; germination and viability decreased when seeds were stored at ambient temperature (22-24 °C), and when they were preserved inside fruits. The seeds of C. alata germinate better at 30 °C, exposed to light, and separated from the pulp before storage. When seeds are stored at low temperatures (5 °C and 15 °C), high germination and viability percentages (ca. 90 %) can be maintained for three years, allowing conservation programs for the species.

Preparo da semente de arroz para execução do teste de tetrazólio / Rice seed preparation for the tetrazolium test

A calibração de metodologias capazes de determinar de forma rápida e eficiente a qualidade de um lote de sementes de arroz, mediante testes de viabilidade como o de tetrazólio, ainda carece de ajustes. O objetivo deste estudo foi avaliar alternativas de preparo e corte das sementes para avaliação da viabilidade de sementes de arroz. O trabalho foi conduzido em duas etapas: a) necessidade de remoção da casca (pálea e lema) e b) corte das sementes,para avaliar a viabilidade de sementes de arroz. Foram utilizadas sementes de quatro cultivares de arroz irrigado (Puitá Inta CL, BR IRGA 424, SCS 116 Satoru e SCS 117 CL) e duas de sequeiro (BRS Serra Dourada e BRS Esmeralda), cada uma representada por dois lotes, totalizando doze lotes avaliados. Os lotes foram inicialmente caracterizados quanto ao teor de água, percentual de germinação e de emergência de plântulas. Posteriormente, o estudo foi dividido em duas etapas, sendo conduzido de forma sequencial, sendo o resultado da etapa I utilizado como base para prosseguir na etapa II. Na primeira etapa, foi avaliada a necessidade da remoção ou não da pálea e da lema das sementes para a execução do teste de tetrazólio. Na segunda etapa, as sementes sem a pálea e a lema, foram avaliadas quanto ao tipo de corte longitudinal, transversal ou sem corte. Os resultados indicaram que para a avaliação da viabilidade de sementes de arroz pelo teste de tetrazólio é recomendável a remoção da pálea e lema, sendo mais eficiente o corte longitudinal na metade distal do eixo embrionário. A remoção da pálea e a lema associada ao corte longitudinal na metade distal do embrião facilita a avaliação da viabilidade de sementes de arroz pelo teste de tetrazólio.(AU)

The calibration of methodologies able to identifying the quality of a rice seed lot, quickly and efficiently through viability tests such as tetrazolium, still lacks adjustments. The aim of this study was to evaluate seed preparation and cutting alternatives to assess the viability of rice seeds. The study was conducted in two stages: a) need to remove the bark (palea and lemma) and b) cutting the seeds to evaluate the viability of rice seeds. Seeds of four cultivars of irrigated rice (Puitá Inta CL, BR IRGA 424, SCS 116 Satoru and SCS 117 CL) and two cultivars of dry rice (BRS Serra Dourada and BRS Esmeralda) were used, each represented by two lots, totaling twelve lots evaluated. The seed lots were initial characterized in terms of water content, germination test, and seedlings emergence. Subsequently, the study was divided in two stages, being conducted in a sequential manner, the result of stage I being used as a basis to proceed in stage II. In the first step, it was evaluated the need of the removal or not the palea and lemma for the execution of the tetrazolium test. In the second step, we evaluated the seeds without the palea and lemma for the longitudinal, transverse cut or uncut. The results indicated that for the evaluation of the viability of rice seeds by the tetrazolium test it is recommended the removal of the palea and lemma, being more efficient the longitudinal cut in the distal half of the embryonic axis. Removal of the palea and lemma associated with the longitudinal cut in the distal half of the embryo facilitate the evaluation of the viability of rice seeds by the tetrazolium test.(AU)

Preparo da semente de arroz para execução do teste de tetrazólio / Rice seed preparation for the tetrazolium test

A calibração de metodologias capazes de determinar de forma rápida e eficiente a qualidade de um lote de sementes de arroz, mediante testes de viabilidade como o de tetrazólio, ainda carece de ajustes. O objetivo deste estudo foi avaliar alternativas de preparo e corte das sementes para avaliação da viabilidade de sementes de arroz. O trabalho foi conduzido em duas etapas: a) necessidade de remoção da casca (pálea e lema) e b) corte das sementes,para avaliar a viabilidade de sementes de arroz. Foram utilizadas sementes de quatro cultivares de arroz irrigado (Puitá Inta CL, BR IRGA 424, SCS 116 Satoru e SCS 117 CL) e duas de sequeiro (BRS Serra Dourada e BRS Esmeralda), cada uma representada por dois lotes, totalizando doze lotes avaliados. Os lotes foram inicialmente caracterizados quanto ao teor de água, percentual de germinação e de emergência de plântulas. Posteriormente, o estudo foi dividido em duas etapas, sendo conduzido de forma sequencial, sendo o resultado da etapa I utilizado como base para prosseguir na etapa II. Na primeira etapa, foi avaliada a necessidade da remoção ou não da pálea e da lema das sementes para a execução do teste de tetrazólio. Na segunda etapa, as sementes sem a pálea e a lema, foram avaliadas quanto ao tipo de corte longitudinal, transversal ou sem corte. Os resultados indicaram que para a avaliação da viabilidade de sementes de arroz pelo teste de tetrazólio é recomendável a remoção da pálea e lema, sendo mais eficiente o corte longitudinal na metade distal do eixo embrionário. A remoção da pálea e a lema associada ao corte longitudinal na metade distal do embrião facilita a avaliação da viabilidade de sementes de arroz pelo teste de tetrazólio.

The calibration of methodologies able to identifying the quality of a rice seed lot, quickly and efficiently through viability tests such as tetrazolium, still lacks adjustments. The aim of this study was to evaluate seed preparation and cutting alternatives to assess the viability of rice seeds. The study was conducted in two stages: a) need to remove the bark (palea and lemma) and b) cutting the seeds to evaluate the viability of rice seeds. Seeds of four cultivars of irrigated rice (Puitá Inta CL, BR IRGA 424, SCS 116 Satoru and SCS 117 CL) and two cultivars of dry rice (BRS Serra Dourada and BRS Esmeralda) were used, each represented by two lots, totaling twelve lots evaluated. The seed lots were initial characterized in terms of water content, germination test, and seedling’s emergence. Subsequently, the study was divided in two stages, being conducted in a sequential manner, the result of stage I being used as a basis to proceed in stage II. In the first step, it was evaluated the need of the removal or not the palea and lemma for the execution of the tetrazolium test. In the second step, we evaluated the seeds without the palea and lemma for the longitudinal, transverse cut or uncut. The results indicated that for the evaluation of the viability of rice seeds by the tetrazolium test it is recommended the removal of the palea and lemma, being more efficient the longitudinal cut in the distal half of the embryonic axis. Removal of the palea and lemma associated with the longitudinal cut in the distal half of the embryo facilitate the evaluation of the viability of rice seeds by the tetrazolium test.

Physiological diversity in Brazilian common bean (Phaseolus vulgaris L) landraces based on selection index / Diversidade fisiológica em feijão comum brasileiro (Phaseolus vulgaris L) com base no índice de seleção

Common bean landraces represent heterogeneous, local adaptations of domesticated species, and thereby provide genetic resources that meet current and new challenges for farming. These local ecotypes can show variable phenology and low-to-moderate edible yield, however, they are highly nutritious. Therefore, strategies to stimulate the conservation of this genetic diversity are important. The maintenance of seed germination potential is also an important feature in the characterization of genetic diversity to conserve biodiversity. The main objective of this study was to discriminate common bean landrace cultivars available at Santa Catarina State University (UDESC) germplasm bank according to their seed physiological diversity and agronomic parameters (germination rate, viability, seed vigor, and seedling growth) and based on Mulamba and Mock selection index. There is a large physiological diversity in common bean landrace cultivars. BAF 112 and BAF 81, BAF 84, BAF 42, BAF 60, and BAF 75, were identified as more promising for the storage of the seeds under conventional conditions, being able to maintain the viability and vigor during storage. Mulamba and Mock selection index were capable of selecting superior cultivars with high physiological quality.(AU)

As variedades crioulas de feijão representam adaptações locais heterogêneas de espécies domesticadas e, assim, fornecem recursos genéticos que atendem aos desafios atuais e novos da agricultura. Estes ecótipos locais podem mostrar fenologia variável e produtividade, baixa a moderada, mas são altamente nutritivos. Portanto, estratégias para estimular a conservação dessa diversidade genética são importantes. A manutenção do potencial de germinação de sementes também é uma característica relevante na caracterização da diversidade genética, a fim de conservar a biodiversidade. Objetivou-se com este trabalho discriminar cultivares de feijão da Universidade Estadual de Santa Catarina (UDESC) quanto à diversidade fisiológica de sementes e parâmetros agronômicos (taxa de germinação, viabilidade, vigor de sementes e crescimento de plântulas) e com base em Mulamba e Índice de seleção de simulação. Existe uma grande diversidade fisiológica nas cultivares de feijão. BAF 112 e BAF 81, BAF 84, BAF 42, BAF 60 e BAF 75, foram identificados como os mais promissores para o armazenamento de sementes sob condições convencionais, sendo capazes de manter a viabilidade e vigor durante o armazenamento. O índice de seleção de Mulamba e Mock foi capaz de selecionar cultivares superiores com alta qualidade fisiológica.(AU)

Physiological diversity in Brazilian common bean (Phaseolus vulgaris L) landraces based on selection index / Diversidade fisiológica em feijão comum brasileiro (Phaseolus vulgaris L) com base no índice de seleção

Common bean landraces represent heterogeneous, local adaptations of domesticated species, and thereby provide genetic resources that meet current and new challenges for farming. These local ecotypes can show variable phenology and low-to-moderate edible yield, however, they are highly nutritious. Therefore, strategies to stimulate the conservation of this genetic diversity are important. The maintenance of seed germination potential is also an important feature in the characterization of genetic diversity to conserve biodiversity. The main objective of this study was to discriminate common bean landrace cultivars available at Santa Catarina State University (UDESC) germplasm bank according to their seed physiological diversity and agronomic parameters (germination rate, viability, seed vigor, and seedling growth) and based on Mulamba and Mock selection index. There is a large physiological diversity in common bean landrace cultivars. BAF 112 and BAF 81, BAF 84, BAF 42, BAF 60, and BAF 75, were identified as more promising for the storage of the seeds under conventional conditions, being able to maintain the viability and vigor during storage. Mulamba and Mock selection index were capable of selecting superior cultivars with high physiological quality.

As variedades crioulas de feijão representam adaptações locais heterogêneas de espécies domesticadas e, assim, fornecem recursos genéticos que atendem aos desafios atuais e novos da agricultura. Estes ecótipos locais podem mostrar fenologia variável e produtividade, baixa a moderada, mas são altamente nutritivos. Portanto, estratégias para estimular a conservação dessa diversidade genética são importantes. A manutenção do potencial de germinação de sementes também é uma característica relevante na caracterização da diversidade genética, a fim de conservar a biodiversidade. Objetivou-se com este trabalho discriminar cultivares de feijão da Universidade Estadual de Santa Catarina (UDESC) quanto à diversidade fisiológica de sementes e parâmetros agronômicos (taxa de germinação, viabilidade, vigor de sementes e crescimento de plântulas) e com base em Mulamba e Índice de seleção de simulação. Existe uma grande diversidade fisiológica nas cultivares de feijão. BAF 112 e BAF 81, BAF 84, BAF 42, BAF 60 e BAF 75, foram identificados como os mais promissores para o armazenamento de sementes sob condições convencionais, sendo capazes de manter a viabilidade e vigor durante o armazenamento. O índice de seleção de Mulamba e Mock foi capaz de selecionar cultivares superiores com alta qualidade fisiológica.

A role for fruit structure in seed survival and germination of Swartzia langsdorffii Raddi beyond dispersal.

Diaspore structure has been hypothesised to play a role in seed viability and/or germination of recalcitrant seeds, especially for Swartzia langsdorffii. Thus, this work aims to (i) investigate the in situ contribution of pericarp and aril on seed viability and germination, and (ii) identify morphoanatomical traits of S. langsdorffii diaspores that allow its desiccation-sensitive seeds to remain viable. The role of the pericarp and aril in seed survival and germination was investigated by placing the whole fruit, whole seeds (arillate seed) and bare seeds (without aril) in soil in the forest understorey, assessing germination, emergence, dead, firm and predated seeds, and water content of pericarps, arils and seeds. Correlation analysis was performed between environmental variables and physiological parameters. Histochemical features of diaspores were also investigated. Pericarp water content fell after several months, while the aril maintained its water content. Seeds did not lose water even without the presence of the pericarp and aril. However, presence of the pericarp promoted seed water content, viability and germination long after dispersal. The embryo had a thickened outer periclinal cell wall. Pericarp and aril are not essential to prevent water loss in seeds, but do help to retain seed moisture, favouring viability maintenance and promoting germination during the rainy season. Morphoanatomical features of seeds are suggested as main factors that reduce water loss. Survival of these desiccation-sensitive seeds upon dispersal during the dry season appears to be facilitated by multiple diaspore features that prevent viability loss.

Drying on the germination and vigor of Crataeva tapia L. seeds / Secagem de sementes de Crataeva tapia L. sobre a germinação e vigor

Crataeva tapia L. is a fruit native to the Brazilian savanna, the Caatinga, and is used in the production of soft drinks and other beverages. Given the importance of this species and the lack of knowledge about its seeds, this research aimed to evaluate the physiological quality of C. tapia L. seeds subjected to different environments and drying periods. Seeds were dried for the following time periods: 0 (no drying), 24, 48, 72, 96, and 120 hours, in the laboratory environment (25°C and 90% RH) and in a greenhouse (30°C and 80% RH). After the drying period, seeds from each of the treatments were used for determining the water content, germination, and vigor (using tests for emergence, first count of germination and emergence, rate of germination and emergence, length, and seedling dry weight). The experimental design was completely randomized and a factorial 2×6 scheme (local environment × drying periods) was used with four replicate sets of seeds. The data were subjected to analysis of variance and polynomial regression using quadratic models. The germination and seed vigor reduced as the drying periods increased. For optimum results, the seeds of C. tapia L. must be dried in the laboratory for a period of 48 hours. In addition, their desiccation resistance was classified as intermediate.(AU)

Crataeva tapia L. é uma frutífera nativa da caatinga, cujos frutos são utilizados para a produção de refresco e bebida vinosa. Devido à importância da espécie e a inexistência de informações sobre suas sementes, objetivou-se avaliar a qualidade fisiológica das mesmas quando submetidas a diferentes ambientes e períodos de secagem. As sementes foram submetidas à secagem pelos seguintes períodos 0 (sem secagem), 24, 48, 72, 96 e 120 horas em ambiente de laboratório (25°C e 90% UR) e casa de vegetação (30°C e 80% UR). Após cada período de secagem as sementes foram submetidas à determinação do teor de água e a testes de germinação e vigor (emergência, primeira contagem de germinação e de emergência, índice de velocidade de germinação e de emergência, comprimento e massa seca de plântulas). O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 2×6 (locais e períodos de secagem), em quatro repetições. Os dados foram submetidos à análise de variância e de regressão polinomial, utilizando os modelos linear e quadrático. A germinação e o vigor das sementes são reduzidos com a secagem, principalmente em casa de vegetação. As sementes de Crataeva tapia L. podem ser secas em ambiente de laboratório por um período de 48 horas e são classificadas como intermediárias.(AU)

Phylogeny strongly drives seed dormancy and quality in a climatically buffered hotspot for plant endemism.

BACKGROUND AND AIMS: Models of costs and benefits of dormancy (D) predict that the evolutionarily stable strategy in long-term stable environments is for non-dormancy (ND), but this prediction remains to be tested empirically. We reviewed seed traits of species in the climatically buffered, geologically stable and nutrient-impoverished campo rupestre grasslands in Brazil to test the hypothesis that ND is favoured over D. We examined the relative importance of life-history traits and phylogeny in driving the evolution of D and assessed seed viability at the community level. METHODS: Germination and viability data were retrieved from 67 publications and ND/D was determined for 168 species in 25 angiosperm families. We also obtained the percentage of embryoless, viable and dormant seeds for 74 species. Frequencies of species with dormant and non-dormant seeds were compared with global databases of dormancy distribution. KEY RESULTS: The majority of campo rupestre taxa (62·5 %) had non-dormant seeds, and the ND/D ratio was the highest for any vegetation type on Earth. Dormancy was unrelated to other species life-history traits, suggesting that contemporary factors are poor predictors of D. We found a significant phylogenetic structure in the dormancy categorical trait. Dormancy diversity was highly skewed towards the root of the phylogenetic tree and there was a strong phylogenetic signal in the data, suggesting a major role of phylogeny in determining the evolution of D versus ND and seed viability. Quantitative analysis of the data revealed that at least half of the seeds produced by 46 % of the surveyed populations were embryoless and/or otherwise non-viable. CONCLUSIONS: Our results support the view that long-term climatic and geological stability favour ND. Seed viability data show that campo rupestre species have a markedly low investment in regeneration from seeds, highlighting the need for specific in situ and ex situ conservation strategies to avoid loss of biodiversity.

Drying on the germination and vigor of Crataeva tapia L. seeds / Secagem de sementes de Crataeva tapia L. sobre a germinação e vigor

ABSTRACT: Crataeva tapia L. is a fruit native to the Brazilian savanna, the Caatinga, and is used in the production of soft drinks and other beverages. Given the importance of this species and the lack of knowledge about its seeds, this research aimed to evaluate the physiological quality of C. tapia L. seeds subjected to different environments and drying periods. Seeds were dried for the following time periods: 0 (no drying), 24, 48, 72, 96, and 120 hours, in the laboratory environment (25°C and 90% RH) and in a greenhouse (30°C and 80% RH). After the drying period, seeds from each of the treatments were used for determining the water content, germination, and vigor (using tests for emergence, first count of germination and emergence, rate of germination and emergence, length, and seedling dry weight). The experimental design was completely randomized and a factorial 2×6 scheme (local environment × drying periods) was used with four replicate sets of seeds. The data were subjected to analysis of variance and polynomial regression using quadratic models. The germination and seed vigor reduced as the drying periods increased. For optimum results, the seeds of C. tapia L. must be dried in the laboratory for a period of 48 hours. In addition, their desiccation resistance was classified as intermediate.

RESUMO: Crataeva tapia L. é uma frutífera nativa da caatinga, cujos frutos são utilizados para a produção de refresco e bebida vinosa. Devido à importância da espécie e a inexistência de informações sobre suas sementes, objetivou-se avaliar a qualidade fisiológica das mesmas quando submetidas a diferentes ambientes e períodos de secagem. As sementes foram submetidas à secagem pelos seguintes períodos 0 (sem secagem), 24, 48, 72, 96 e 120 horas em ambiente de laboratório (25°C e 90% UR) e casa de vegetação (30°C e 80% UR). Após cada período de secagem as sementes foram submetidas à determinação do teor de água e a testes de germinação e vigor (emergência, primeira contagem de germinação e de emergência, índice de velocidade de germinação e de emergência, comprimento e massa seca de plântulas). O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 2×6 (locais e períodos de secagem), em quatro repetições. Os dados foram submetidos à análise de variância e de regressão polinomial, utilizando os modelos linear e quadrático. A germinação e o vigor das sementes são reduzidos com a secagem, principalmente em casa de vegetação. As sementes de Crataeva tapia L. podem ser secas em ambiente de laboratório por um período de 48 horas e são classificadas como intermediárias.

Drying on the germination and vigor of Crataeva tapia L. seeds / Secagem de sementes de Crataeva tapia L. sobre a germinação e vigor

Crataeva tapia L. is a fruit native to the Brazilian savanna, the Caatinga, and is used in the production of soft drinks and other beverages. Given the importance of this species and the lack of knowledge about its seeds, this research aimed to evaluate the physiological quality of C. tapia L. seeds subjected to different environments and drying periods. Seeds were dried for the following time periods: 0 (no drying), 24, 48, 72, 96, and 120 hours, in the laboratory environment (25°C and 90% RH) and in a greenhouse (30°C and 80% RH). After the drying period, seeds from each of the treatments were used for determining the water content, germination, and vigor (using tests for emergence, first count of germination and emergence, rate of germination and emergence, length, and seedling dry weight). The experimental design was completely randomized and a factorial 2×6 scheme (local environment × drying periods) was used with four replicate sets of seeds. The data were subjected to analysis of variance and polynomial regression using quadratic models. The germination and seed vigor reduced as the drying periods increased. For optimum results, the seeds of C. tapia L. must be dried in the laboratory for a period of 48 hours. In addition, their desiccation resistance was classified as intermediate.

Crataeva tapia L. é uma frutífera nativa da caatinga, cujos frutos são utilizados para a produção de refresco e bebida vinosa. Devido à importância da espécie e a inexistência de informações sobre suas sementes, objetivou-se avaliar a qualidade fisiológica das mesmas quando submetidas a diferentes ambientes e períodos de secagem. As sementes foram submetidas à secagem pelos seguintes períodos 0 (sem secagem), 24, 48, 72, 96 e 120 horas em ambiente de laboratório (25°C e 90% UR) e casa de vegetação (30°C e 80% UR). Após cada período de secagem as sementes foram submetidas à determinação do teor de água e a testes de germinação e vigor (emergência, primeira contagem de germinação e de emergência, índice de velocidade de germinação e de emergência, comprimento e massa seca de plântulas). O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 2×6 (locais e períodos de secagem), em quatro repetições. Os dados foram submetidos à análise de variância e de regressão polinomial, utilizando os modelos linear e quadrático. A germinação e o vigor das sementes são reduzidos com a secagem, principalmente em casa de vegetação. As sementes de Crataeva tapia L. podem ser secas em ambiente de laboratório por um período de 48 horas e são classificadas como intermediárias.

Identificação da viabilidade de sementes de orquídeas pelo teste de tetrazólio / Orchid seeds viability identification by tetrazolium test

O conhecimento do potencial germinativo otimiza a prática de germinação in vitro de Orchidaceae. Este trabalho avaliou o tipo e a concentração de soluções de tetrazólio sobre o tempo de reação e a identificação de sementes viáveis de orquidáceas. Foram utilizadas sementes das espécies Brassavola tuberculata Hook, Cattleya labiata Lindley var Amoema, Cattleya intermedia e Dendrobium antenatum e de dois híbridos primários de Cattleya labiata autumnalis x Cattleya labiata Lindley var. Alba. As sementes (0,01g) de cada espécie ou híbrido foram embebidas em 3 mL da solução aquosa ou da neutra de cloreto de 2,3,5 trifeniltetrazólio, nas concentrações de 0,0625%, 0,125%, 0,25%, 0,5% ou 1,0%e acondicionadas em ambiente desprovido de luz a 25±2 ºC, sendo avaliadas a cada 30 minutos para identificação do tempo necessário para a coloração dos embriões e posterior contagem do número de sementes viáveis por miligrama de sementes. Utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 6 x 2 x 5 (seis genótipos de orquídeas, dois tipos de soluções tetrazólicas e cinco concentrações) com 3 repetições. Os genótipos estudados responderam diferentemente no que se refere ao número de sementes viáveis por miligrama de sementes e quanto ao tempo necessário para a coloração dos embriões, sendo que C. intermedia não respondeu ao teste. Independentemente do tipo de solução, as concentrações só interferiram no tempo de reação para um dos híbridos. Recomenda-se, portanto, a utilização de solução neutra de tetrazólio a 0,5% para identificação de sementes viáveis dos híbridos de Cattleya labiata autumnalis x Cattleya labiata var. Alba e a utilização de solução aquosa a 0,125% para as espécies Brassavola tuberculata, Cattleya labiata var Amoema e Dendrobium antenatum.(AU)

The knowledge of germinal potential optimizes the practice of in vitro germination of Orchidaceae. This work evaluated of the type and concentrations of tetrazolium solutions on reaction time and on the identification of viable orchid seeds. Were used seeds of the species Brassavola tuberculata Hook, Cattleya labiata Lindley var Amoema, Cattleya intermedia and Dendrobium antenatum and of two primary hybrids of Cattleya labiata autumnalis x Cattleya labiata Lindley var. Alba. The seeds(0.01g) of each species or hybrid were soaked in 3 mL of aqueous and neutral solutions of 2, 3, 5 triphenyltetrazolium chloride at 0.0625%, 0.125%, 0.25%, 0.5% and 1.0% concentrations and stored in a light-free environment at 25±2 °C, being evaluated every 30 minutes for identification of the time needed for embryos coloring and later counting of the number of viable seeds by milligram of seed. A completely randomized design was used, in a factorial scheme 6 x 2 x 5 (six genotypes of orchids, two types of tetrazolium solutions and five concentrations) with 3 replications. The genotypes responded differently both for viable seeds by milligram of seed and for the time required for embryos coloring and C. intermedia not respond to the test. Irrespective of solution type, concentrations only interfered in reaction time for the hybrids. It is recommended, therefore, the use of neutral tetrazolium solution at 0.5% for indentification of viable seeds of hybrids of Cattleya labiata autumnalis x Cattleya labiata var. Alba and use of aqueous solution at 0.125% for Brassavola tuberculata, Cattleya labiata var Amoema and Dendrobium antenatum.(AU)

Identificação da viabilidade de sementes de orquídeas pelo teste de tetrazólio / Orchid seeds viability identification by tetrazolium test

O conhecimento do potencial germinativo otimiza a prática de germinação in vitro de Orchidaceae. Este trabalho avaliou o tipo e a concentração de soluções de tetrazólio sobre o tempo de reação e a identificação de sementes viáveis de orquidáceas. Foram utilizadas sementes das espécies Brassavola tuberculata Hook, Cattleya labiata Lindley var Amoema, Cattleya intermedia e Dendrobium antenatum e de dois híbridos primários de Cattleya labiata autumnalis x Cattleya labiata Lindley var. Alba. As sementes (0,01g) de cada espécie ou híbrido foram embebidas em 3 mL da solução aquosa ou da neutra de cloreto de 2,3,5 trifeniltetrazólio, nas concentrações de 0,0625%, 0,125%, 0,25%, 0,5% ou 1,0%e acondicionadas em ambiente desprovido de luz a 25±2 ºC, sendo avaliadas a cada 30 minutos para identificação do tempo necessário para a coloração dos embriões e posterior contagem do número de sementes viáveis por miligrama de sementes. Utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 6 x 2 x 5 (seis genótipos de orquídeas, dois tipos de soluções tetrazólicas e cinco concentrações) com 3 repetições. Os genótipos estudados responderam diferentemente no que se refere ao número de sementes viáveis por miligrama de sementes e quanto ao tempo necessário para a coloração dos embriões, sendo que C. intermedia não respondeu ao teste. Independentemente do tipo de solução, as concentrações só interferiram no tempo de reação para um dos híbridos. Recomenda-se, portanto, a utilização de solução neutra de tetrazólio a 0,5% para identificação de sementes viáveis dos híbridos de Cattleya labiata autumnalis x Cattleya labiata var. Alba e a utilização de solução aquosa a 0,125% para as espécies Brassavola tuberculata, Cattleya labiata var Amoema e Dendrobium antenatum.

The knowledge of germinal potential optimizes the practice of in vitro germination of Orchidaceae. This work evaluated of the type and concentrations of tetrazolium solutions on reaction time and on the identification of viable orchid seeds. Were used seeds of the species Brassavola tuberculata Hook, Cattleya labiata Lindley var Amoema, Cattleya intermedia and Dendrobium antenatum and of two primary hybrids of Cattleya labiata autumnalis x Cattleya labiata Lindley var. Alba. The seeds(0.01g) of each species or hybrid were soaked in 3 mL of aqueous and neutral solutions of 2, 3, 5 triphenyltetrazolium chloride at 0.0625%, 0.125%, 0.25%, 0.5% and 1.0% concentrations and stored in a light-free environment at 25±2 °C, being evaluated every 30 minutes for identification of the time needed for embryos coloring and later counting of the number of viable seeds by milligram of seed. A completely randomized design was used, in a factorial scheme 6 x 2 x 5 (six genotypes of orchids, two types of tetrazolium solutions and five concentrations) with 3 replications. The genotypes responded differently both for viable seeds by milligram of seed and for the time required for embryos coloring and C. intermedia not respond to the test. Irrespective of solution type, concentrations only interfered in reaction time for the hybrids. It is recommended, therefore, the use of neutral tetrazolium solution at 0.5% for indentification of viable seeds of hybrids of Cattleya labiata autumnalis x Cattleya labiata var. Alba and use of aqueous solution at 0.125% for Brassavola tuberculata, Cattleya labiata var Amoema and Dendrobium antenatum.

Armazenamento não controlado na qualidade de sementes de Jatropha curcas L / Non-controlled storage on Jatropha curcas L seed quality

O ensaio objetivou avaliar a influência do armazenamento não controlado na qualidade de sementes de Jatropha curcas L. As sementes utilizadas foram procedentes de um cultivo comercial localizado em Eldorado (MS) submetidas ao beneficiamento manual e amostradas de acordo com o período de armazenamento em um galpão adjacente à sede da propriedade. Os períodos de armazenamento testados equivaleram a 17, 40, 66, 108 e 164 dias. A qualidade das sementes foi determinada pela da quantificação do teor de água, da massa de mil sementes, da germinação, e do vigor por meio do índice de velocidade de germinação (IVG). Os testes de germinação e vigor em laboratório utilizaram as temperaturas constantes de 25 ou 30 oC e dois substratos de germinação (rolo de papel e entre areia). A porcentagem de germinação e o IVG para sementes com 17 e 40 dias de armazenamento foram de 71,5 % e 29, enquanto que para as sementes dos demais períodos resultaram em valores de 52 %, 21% e 23% e de 19, 21 e 23, respectivamente. Sementes colhidas e armazenadas por até 40 dias em ambiente sombreado não controlado expressaram maior viabilidade e germinaram em menos tempo.

This study aimed to evaluate the effect of storage in the quality of Jatropha curcas L. seeds. Seeds were collected from a commercial stand located in Eldorado (MS). Seeds were manually cleaned and stored in an uncontrolled environment facility. Seeds were sampled according to storage period equivalent to 17, 40, 66, 108 and 164 days. Seed quality was determined by determination of seed water content, the seed mass of 1000 seeds, germination and germination velocity index (GVI). Germination and GVI tests used constant temperatures of 25 or 30 oC and two substrates (sterilized sand and paper rolls). Germination percentage and GVI with seeds stored for 17 and 40 days yielded 71.5 % and 29 while seeds from the other storage periods yielded values of 52 %, 21 % and 23%, and of 19, 21 and 23, respectively. Recent harvested seeds stored for up to 40 days under uncontrolled environment expressed the highest viability and germinated faster than seeds from the stored from longer periods.

Proposta de modelagem não-linear do desempenho germinativo de sementes de milho híbrido / Nonlinear proposal modeling of seed germination performance of hybrid corn seeds

Este trabalho foi desenvolvido com o objetivo de ajustar um modelo de regressão não-linear para estimar o desempenho germinativo de sementes de três lotes comerciais de milho híbrido OC 705, submetidas ao teste de envelhecimento acelerado, à temperatura de 43ºC. Utilizou-se o modelo logístico y(t)=C/(1+exp(B(t-M))) para ajustar os dados. As medidas de viés de Box e de curvaturas paramétrica e intrínseca foram usadas para o diagnóstico do modelo. O modelo proposto ajusta-se adequadamente aos dados de percentuais germinativos de sementes de milho híbrido OC 705, para todos os lotes. Com base nas estimativas dos parâmetros e qualidade de ajuste, o lote três foi identificado como sendo o melhor para comercialização, por apresentar menor redução no poder germinativo ao longo do tempo.

This research was developed with the goal to adjust a nonlinear regression model to estimate seed germination performance of three commercial seed lots of hybrid maize OC 705, subjected to accelerated aging test at a temperature of 43oC. The logistic model y(t)=C/(1+exp (B (t-M))) was used to fit the data. Measures of bias Box and parametric intrinsic bends were used for the diagnosis of the model. The proposed model fits properly to seed germination percentage data of hybrid corn seeds for OC 705, for all seed lots. Based on estimates of the parameters and fit quality, the seed lot three was identified as being the best for marketing, by presenting less reduction in seed germination power over time.