Bayesian sequential procedure to estimate the viability of seeds Coffea arabica L. in tetrazolium test

Tetrazolium tests use conventional sampling techniques in which a sample has a fixed size. These tests may be improved by sequential sampling, which does not work with fixed-size samples. When data obtained from an experiment are analyzed sequentially the analysis can be terminated when a particular decision has been made, and thus, there is no need to pre-establish the number of seeds to assess. Bayesian statistics can also help, if we have sufficient knowledge about coffee production in the area to construct a prior distribution. Therefore, we used the Bayesian sequential approach to estimate the percentage of viable coffee seeds submitted to tetrazolium testing, and we incorporated priors with information from other analyses of crops from previous years. We used the Beta prior distribution and, using data obtained from sample lots of Coffea arabica, determined its hyperparameters with a histogram and O’Hagan's methods. To estimate the lowest risk, we computed the Bayes risks, which provided us with a basis for deciding whether or not we should continue the sampling process. The results confirm that the Bayesian sequential estimation can indeed be used for the tetrazolium test: the average percentage of viability obtained with the conventional frequentist method was 88 %, whereas that obtained with the Bayesian method with both priors was 89 %. However, the Bayesian method required, on average, only 89 samples to reach this value while the traditional estimation method needed as many as 200 samples.

Bayesian sequential procedure to estimate the viability of seeds Coffea arabica L. in tetrazolium test

Tetrazolium tests use conventional sampling techniques in which a sample has a fixed size. These tests may be improved by sequential sampling, which does not work with fixed-size samples. When data obtained from an experiment are analyzed sequentially the analysis can be terminated when a particular decision has been made, and thus, there is no need to pre-establish the number of seeds to assess. Bayesian statistics can also help, if we have sufficient knowledge about coffee production in the area to construct a prior distribution. Therefore, we used the Bayesian sequential approach to estimate the percentage of viable coffee seeds submitted to tetrazolium testing, and we incorporated priors with information from other analyses of crops from previous years. We used the Beta prior distribution and, using data obtained from sample lots of Coffea arabica, determined its hyperparameters with a histogram and OHagan's methods. To estimate the lowest risk, we computed the Bayes risks, which provided us with a basis for deciding whether or not we should continue the sampling process. The results confirm that the Bayesian sequential estimation can indeed be used for the tetrazolium test: the average percentage of viability obtained with the conventional frequentist method was 88 %, whereas that obtained with the Bayesian method with both priors was 89 %. However, the Bayesian method required, on average, only 89 samples to reach this value while the traditional estimation method needed as many as 200 samples.(AU)

Substrate and temperature on germination and performance of Albizia niopoides Benth. Seedlings / Substrato e temperatura na germinação e desempenho de plântulas de Albizia niopoides

This study aimed to determine the most appropriate conditions of temperature and substrate for germination and performance of A. niopoides seedlings. The design was completely randomized in 10x7 factorial arrangement (eight constant temperatures of 5, 10, 15, 20, 25, 30, 35, and 40°C and two alternating temperatures of 20-30 and 25-35°C, and seven substrates, that are paper towel, vermiculite, sand, blotting paper, coir dust, sugarcane bagasse, and tropstrato®) with four replicates of 25 seeds. The following variables were analyzed: (1) germination percentage; (2) germination speed index; (3) shoot length and primary root; and (4) dry weight of shoot and of root system. There was a significant interaction among the tested factors for all variables. The A. niopoides seeds germinate under a wide temperature range, with minimum and maximum limit at 10 and 40°C temperatures, respectively. Alternating temperatures of 20-30 and 25-35°C with sand substrate are ideal conditions for germination and performance of A. niopoides seedlings.(AU)

Objetivou-se com a realização deste estudo determinar as condições mais adequadas de temperatura e substrato para germinação e desempenho de plântulas de Albizia niopoides. O delineamento utilizado foi o inteiramente casualizado em arranjo fatorial 10x7 (oito temperaturas constantes de 5, 10, 15, 20, 25, 30, 35 e 40°C e duas alternadas 20-30 e 25-35°C e sete substratos: papel tolha, vermiculita, areia, papel mata borrão, pó de coco, bagaço de cana e tropstrato®), com quatro repetições de 25 sementes. Foram analisadas as seguintes variáveis: percentagem de germinação, índice de velocidade de germinação, comprimento de parte aérea e raiz primária e massa seca da parte aérea e do sistema radicular. Houve interação significativa dos fatores testados para as todas as variáveis analisadas. As sementes de A. niopoides germinam em uma ampla faixa de temperatura, com limite mínimo e máximo nas temperaturas de 10 e 40°C, respectivamente. As temperaturas alternadas de 20-30°C e 25-35 °C com o substrato areia são condições ideais para germinação e desempenho de plântulas de A. niopoides.(AU)

Substrate and temperature on germination and performance of Albizia niopoides Benth. Seedlings / Substrato e temperatura na germinação e desempenho de plântulas de Albizia niopoides

This study aimed to determine the most appropriate conditions of temperature and substrate for germination and performance of A. niopoides seedlings. The design was completely randomized in 10x7 factorial arrangement (eight constant temperatures of 5, 10, 15, 20, 25, 30, 35, and 40°C and two alternating temperatures of 20-30 and 25-35°C, and seven substrates, that are paper towel, vermiculite, sand, blotting paper, coir dust, sugarcane bagasse, and tropstrato®) with four replicates of 25 seeds. The following variables were analyzed: (1) germination percentage; (2) germination speed index; (3) shoot length and primary root; and (4) dry weight of shoot and of root system. There was a significant interaction among the tested factors for all variables. The A. niopoides seeds germinate under a wide temperature range, with minimum and maximum limit at 10 and 40°C temperatures, respectively. Alternating temperatures of 20-30 and 25-35°C with sand substrate are ideal conditions for germination and performance of A. niopoides seedlings.

Objetivou-se com a realização deste estudo determinar as condições mais adequadas de temperatura e substrato para germinação e desempenho de plântulas de Albizia niopoides. O delineamento utilizado foi o inteiramente casualizado em arranjo fatorial 10x7 (oito temperaturas constantes de 5, 10, 15, 20, 25, 30, 35 e 40°C e duas alternadas 20-30 e 25-35°C e sete substratos: papel tolha, vermiculita, areia, papel mata borrão, pó de coco, bagaço de cana e tropstrato®), com quatro repetições de 25 sementes. Foram analisadas as seguintes variáveis: percentagem de germinação, índice de velocidade de germinação, comprimento de parte aérea e raiz primária e massa seca da parte aérea e do sistema radicular. Houve interação significativa dos fatores testados para as todas as variáveis analisadas. As sementes de A. niopoides germinam em uma ampla faixa de temperatura, com limite mínimo e máximo nas temperaturas de 10 e 40°C, respectivamente. As temperaturas alternadas de 20-30°C e 25-35 °C com o substrato areia são condições ideais para germinação e desempenho de plântulas de A. niopoides.

Vigor tests to evaluate the physiological quality of corn seeds cv. 'Sertanejo'

ABSTRACT: The vigor tests are intended to monitor the quality of seeds as it allows reliably distinguish lots of low and high vigor, providing additional information to the germination test. So in this study the objective was to identify the most efficient vigor tests on stratification of lots of corn seeds cv. 'Sertanejo'. The experiment was conducted at Laboratory of Seed Analysis at the Center of agricultural Science of the Universidade Federal da Paraíba, using samples from 20 seed lots in a completely randomized design. For characterization of the lots it was evaluated water content, germination and vigor (cold test, electrical conductivity, accelerated aging, seedling emergence in field and germination at low temperatures). The accelerated aging, electrical conductivity and field emergence of seedlings tests are the most efficient for classification of lots of corn seeds cv. 'Sertanejo' in levels of vigor, been the seeds of lot 1 the most vigorous.

RESUMO: Os testes de vigor têm como finalidade monitorar a qualidade das sementes, pois permite distinguir com segurança os lotes de baixo e alto vigor, fornecendo informações adicionais ao teste de germinação. Assim, no presente trabalho, objetivou-se identificar os testes de vigor mais eficientes na estratificação de lotes de sementes de milho cv. 'Sertanejo'. O experimento foi realizado no Laboratório de Análise de Sementes do Centro de Ciências Agrárias da Universidade Federal da Paraíba, utilizando amostras de 20 lotes de sementes, em delineamento inteiramente ao acaso. Para caracterização dos lotes foram avaliados o teor de água, a germinação e o vigor (teste de frio, condutividade elétrica, envelhecimento acelerado, emergência de plântulas em campo e germinação a baixa temperatura). Os testes de envelhecimento acelerado, condutividade elétrica e emergência de plântulas em campo são os mais eficientes para classificação dos lotes de sementes de milho cv. 'Sertanejo', em níveis de vigor, sendo as sementes do lote 1 mais vigorosas.

Use of the software Seed Vigor Imaging System (SVIS®) for assessing vigor of carrot seeds

Seed vigor has traditionally been evaluated by physiological, biochemical and stress tolerance tests. More recently, with the use of computerized image analysis, objective information has become accessible in a relatively short period of time, with less human interference. The aim of this study was to verify the efficiency of computerized seedling image analysis by Seed Vigor Imaging System (SVIS®) to detect differences in vigor between carrot (Daucus carota L.) seed lots as compared to those provided by traditional vigor tests. Seeds from seven lots from the Brasilia cultivar were subjected to a germination test, first count of germination, speed of germination, accelerated aging with saline solution and seedling emergence; furthermore, a vigor index, growth index and uniformity index were determined by the Seed Vigor Imaging System (SVIS®) during four evaluation periods. The results obtained by the computerized seedling analysis (vigor index and growth index) show that SVIS® is efficient in assessing carrot seed vigor.

Vigor tests to evaluate the physiological quality of corn seeds cv. "Sertanejo" / Testes de vigor para avaliar a qualidade fisiológica de sementes de milho cv. Sertanejo

The vigor tests are intended to monitor the quality of seeds as it allows reliably distinguish lots of low and high vigor, providing additional information to the germination test. So in this study the objective was to identify the most efficient vigor tests on stratification of lots of corn seeds cv. "Sertanejo". The experiment was conducted at Laboratory of Seed Analysis at the Center of agricultural Science of the Universidade Federal da Paraíba, using samples from 20 seed lots in a completely randomized design. For characterization of the lots it was evaluated water content, germination and vigor (cold test, electrical conductivity, accelerated aging, seedling emergence in field and germination at low temperatures). The accelerated aging, electrical conductivity and field emergence of seedlings tests are the most efficient for classification of lots of corn seeds cv. "Sertanejo" in levels of vigor, been the seeds of lot 1 the most vigorous.

Os testes de vigor têm como finalidade monitorar a qualidade das sementes, pois permite distinguir com segurança os lotes de baixo e alto vigor, fornecendo informações adicionais ao teste de germinação. Assim, no presente trabalho, objetivou-se identificar os testes de vigor mais eficientes na estratificação de lotes de sementes de milho cv. "Sertanejo". O experimento foi realizado no Laboratório de Análise de Sementes do Centro de Ciências Agrárias da Universidade Federal da Paraíba, utilizando amostras de 20 lotes de sementes, em delineamento inteiramente ao acaso. Para caracterização dos lotes foram avaliados o teor de água, a germinação e o vigor (teste de frio, condutividade elétrica, envelhecimento acelerado, emergência de plântulas em campo e germinação a baixa temperatura). Os testes de envelhecimento acelerado, condutividade elétrica e emergência de plântulas em campo são os mais eficientes para classificação dos lotes de sementes de milho cv. "Sertanejo", em níveis de vigor, sendo as sementes do lote 1 mais vigorosas.

Use of the software Seed Vigor Imaging System (SVIS®) for assessing vigor of carrot seeds

Seed vigor has traditionally been evaluated by physiological, biochemical and stress tolerance tests. More recently, with the use of computerized image analysis, objective information has become accessible in a relatively short period of time, with less human interference. The aim of this study was to verify the efficiency of computerized seedling image analysis by Seed Vigor Imaging System (SVIS®) to detect differences in vigor between carrot (Daucus carota L.) seed lots as compared to those provided by traditional vigor tests. Seeds from seven lots from the Brasilia cultivar were subjected to a germination test, first count of germination, speed of germination, accelerated aging with saline solution and seedling emergence; furthermore, a vigor index, growth index and uniformity index were determined by the Seed Vigor Imaging System (SVIS®) during four evaluation periods. The results obtained by the computerized seedling analysis (vigor index and growth index) show that SVIS® is efficient in assessing carrot seed vigor.(AU)

Vigor tests to evaluate the physiological quality of corn seeds cv. "Sertanejo" / Testes de vigor para avaliar a qualidade fisiológica de sementes de milho cv. Sertanejo

The vigor tests are intended to monitor the quality of seeds as it allows reliably distinguish lots of low and high vigor, providing additional information to the germination test. So in this study the objective was to identify the most efficient vigor tests on stratification of lots of corn seeds cv. "Sertanejo". The experiment was conducted at Laboratory of Seed Analysis at the Center of agricultural Science of the Universidade Federal da Paraíba, using samples from 20 seed lots in a completely randomized design. For characterization of the lots it was evaluated water content, germination and vigor (cold test, electrical conductivity, accelerated aging, seedling emergence in field and germination at low temperatures). The accelerated aging, electrical conductivity and field emergence of seedlings tests are the most efficient for classification of lots of corn seeds cv. "Sertanejo" in levels of vigor, been the seeds of lot 1 the most vigorous. (AU)

Os testes de vigor têm como finalidade monitorar a qualidade das sementes, pois permite distinguir com segurança os lotes de baixo e alto vigor, fornecendo informações adicionais ao teste de germinação. Assim, no presente trabalho, objetivou-se identificar os testes de vigor mais eficientes na estratificação de lotes de sementes de milho cv. "Sertanejo". O experimento foi realizado no Laboratório de Análise de Sementes do Centro de Ciências Agrárias da Universidade Federal da Paraíba, utilizando amostras de 20 lotes de sementes, em delineamento inteiramente ao acaso. Para caracterização dos lotes foram avaliados o teor de água, a germinação e o vigor (teste de frio, condutividade elétrica, envelhecimento acelerado, emergência de plântulas em campo e germinação a baixa temperatura). Os testes de envelhecimento acelerado, condutividade elétrica e emergência de plântulas em campo são os mais eficientes para classificação dos lotes de sementes de milho cv. "Sertanejo", em níveis de vigor, sendo as sementes do lote 1 mais vigorosas. (AU)

Germination of amaranth seeds under influence of light, substrate and temperature / Germinação de sementes de amaranto sob influência da luz, substrato e temperatura

Seed germination involves complex physiological and biochemical mechanisms. The cultivation of amaranth, of great food importance, lacks information about this process. The aim of this study was to evaluate the effect of temperature, light and different substrates on the germination of amaranth seeds. The experimental design was entirely randomized in a trifactorial scheme, with two temperatures, two conditions of light and four substrates, with four repetitions of 100 seeds each. The percentage of seed germination was evaluated until 24 days of implementation and the cumulative germination at 07, 14 and 24 days. The germination began on the fourth day for the substrate between sand and for the other substrates it began on the eleventh day, stabilizing in the fourteenth day. There was triple significant interaction among temperature, light condition and substrate factors used on the germination test. The best condition for amaranth seed germination is at a 25ºC temperature, in the absence of light and on paper roll substrate, with 87% of germination. These conditions can be used in germination tests for seed lots, to test its quality.

A germinação das sementes envolve complexos mecanismos fisiológicos e bioquímicos. A cultura do amaranto, de grande importância alimentar, carece de informações quanto à este processo. O objetivo deste trabalho foi avaliar o efeito da temperatura, da luz e de diferentes substratos sobre a germinação de sementes de amaranto. O experimento foi realizado em esquema trifatorial, sendo duas temperaturas, duas condições de luz e quatro substratos. Adotou-se o delineamento experimental inteiramente casualizado, com quatro repetições de 100 sementes cada. Foi avaliado o percentual de germinação das sementes até 24 dias da implantação e a germinação acumulada aos 07, 14 e 24 dias. A germinação teve início no 4 dia para o substrato entre areia e para os demais substratos teve início no 11 dia, estabilizando-se no 14 dia. Houve interação tripla significativa entre os fatores temperatura, condição de luz e substrato utilizado no teste de germinação. A melhor condição para a germinação de sementes de amaranto é na temperatura de 25ºC, na ausência de luz e em substrato rolo de papel, com 87% de germinação. Estas condições podem ser utilizadas em testes de germinação de lotes de sementes para atestar sua qualidade.

Dormancy overcoming, temperatures and substrates on germination of Mimosa tenuiflora Willd seeds / Superação de dormência, temperaturas e substratos na germinação de sementes de Mimosa tenuiflora Willd

Mimosa tenuiflora Willd., popularly known as jurema-preta, is an arboreal species of great importance for the brazilian Northeast due to its uses as a medicinal plant and in the restoration of degraded soils. No information is available in the Rules for Seed Analysis and the Instructions for Seed Analysis of Forest Species regarding ideal conditions for of this species. Thus, this study aimed at evaluating the influence of pre-germination treatments, in addition to verifying the germination performance at different temperatures and in different substrates. In both experiments, four replicates of 25 seeds were used for each treatment. In experiment I, seeds were submitted to the following methods for overcoming dormancy: witness Intact seeds (T1) immersion in water at 100 °C for 1 (T2), 2 (T3), 3 (T4), 4 (T5), 5 (T6) and 6 min (T7), immersion in concentrated sulfuric acid for 1 (T8), 4 (T9), 7 (T10), 10 (T11) and 13 min (T12), scarification on sandpaper n° 80 (T13) and lopping in the region opposite the micropyle (T14). In experiment II, seed germination was evaluated in four types of substrates: between sand, paper on, paper roll and between vermiculite and at six different temperatures: 20, 25, 30, 35, 40 °C and alternating between 20 and 30 °C. Immersion in hot water for 1, 2, 3, 4, 5 and 6 min, sulfuric acid treatment for 10 and 13 min, sand paper and lopping were the most appropriate treatments to overcome seed dormancy. The seed germination of M. Tenuiflora should be carried out at 25 °C on paper roll substrate.(AU)

Mimosa tenuiflora Willd., conhecida popularmente como jurema-preta é uma espécie arbórea de grande importância para o Nordeste brasileiro pela sua multiplicidade de usos, como na medicina popular, recuperação de solos degradados e fixação de nitrogênio. Ainda não há informações disponíveis nas Regras para Análise de Sementes e nas Instruções para Análise de Sementes de Espécies Florestais com relação às condições ideais para condução do teste de germinação desta espécie. Dessa forma, objetivou-se avaliar a influência da aplicação de tratamentos pré-germinativos, além de verificar o desempenho da germinação em diferentes temperaturas e substratos. Em ambos os experimentos foram utilizados quatro repetições de 25 sementes para cada tratamento. No experimento I, as sementes foram submetidas aos seguintes métodos para superação de dormência: testemunha sementes intactas (T1), imersão em água a 100 °C por um (T2), dois (T3), três (T4), quatro (T5), cinco (T6) e seis minutos (T7), imersão em ácido sulfúrico concentrado por um (T8), quatro (T9), sete (T10), dez (T11) e treze minutos (T12), escarificação em lixa n° 80 (T13) e desponte na região oposta a micrópila (T14). No experimento II, a germinação das sementes foi avaliada em quatro tipos de substratos: entre areia, sobre papel, rolo de papel e entre vermiculita e em seis temperaturas: 20 °C, 25 °C, 30 °C, 35 °C, 40 °C e alternada 20- 30 °C. A imersão em água quente por 1, 2, 3, 4, 5 e 6 minutos, ácido sulfúrico por 10 e 13 minutos, lixa e desponte são os tratamentos mais indicados para a superação de dormência da espécie. O teste de germinação de sementes de M. tenuiflora pode ser conduzido a 25 °C, no substrato rolo de papel.(AU)

Germination of amaranth seeds under influence of light, substrate and temperature / Germinação de sementes de amaranto sob influência da luz, substrato e temperatura

Seed germination involves complex physiological and biochemical mechanisms. The cultivation of amaranth, of great food importance, lacks information about this process. The aim of this study was to evaluate the effect of temperature, light and different substrates on the germination of amaranth seeds. The experimental design was entirely randomized in a trifactorial scheme, with two temperatures, two conditions of light and four substrates, with four repetitions of 100 seeds each. The percentage of seed germination was evaluated until 24 days of implementation and the cumulative germination at 07, 14 and 24 days. The germination began on the fourth day for the substrate between sand and for the other substrates it began on the eleventh day, stabilizing in the fourteenth day. There was triple significant interaction among temperature, light condition and substrate factors used on the germination test. The best condition for amaranth seed germination is at a 25ºC temperature, in the absence of light and on paper roll substrate, with 87% of germination. These conditions can be used in germination tests for seed lots, to test its quality.(AU)

A germinação das sementes envolve complexos mecanismos fisiológicos e bioquímicos. A cultura do amaranto, de grande importância alimentar, carece de informações quanto à este processo. O objetivo deste trabalho foi avaliar o efeito da temperatura, da luz e de diferentes substratos sobre a germinação de sementes de amaranto. O experimento foi realizado em esquema trifatorial, sendo duas temperaturas, duas condições de luz e quatro substratos. Adotou-se o delineamento experimental inteiramente casualizado, com quatro repetições de 100 sementes cada. Foi avaliado o percentual de germinação das sementes até 24 dias da implantação e a germinação acumulada aos 07, 14 e 24 dias. A germinação teve início no 4 dia para o substrato entre areia e para os demais substratos teve início no 11 dia, estabilizando-se no 14 dia. Houve interação tripla significativa entre os fatores temperatura, condição de luz e substrato utilizado no teste de germinação. A melhor condição para a germinação de sementes de amaranto é na temperatura de 25ºC, na ausência de luz e em substrato rolo de papel, com 87% de germinação. Estas condições podem ser utilizadas em testes de germinação de lotes de sementes para atestar sua qualidade.(AU)

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)

Germinação sob altas temperaturas para avaliação do potencial fisiológico de sementes de milho / Germination at high temperatures in evaluation of maize vigor

O objetivo do trabalho foi avaliar e padronizar o teste de germinação sob altas temperaturas para avaliação do vigor de sementes de milho. Foram utilizados seis lotes de sementes de milho híbrido com diferentes níveis de vigor e potenciais germinativos semelhantes em três temperaturas (31, 34 e 37°C), em esquema fatorial 3x6, com quatro repetições. Além da caracterização da qualidade fisiológica pelos métodos padrão, foram determinados, sob altas temperaturas, a germinação, primeira contagem, comprimento e massa seca da raiz e parte aérea das plântulas. Os dados foram submetidos à análise de variância, comparação de médias pelo teste de Tukey e estudo de correlação linear simples a 5%, respectivamente. As temperaturas de 31, 34 e 37ºC mostraram-se eficientes para a avaliação do vigor de lotes de sementes de milho. A temperatura de 34ºC mostrou-se mais adequada para avaliação do potencial fisiológico de sementes de milho, com maiores valores de correlação com os testes laboratoriais e com a emergência e índice de velocidade de emergência de plântulas no campo.(AU)

The objective of the experiment was to evaluate and standardize the germination test under high temperatures to evaluate the vigor of corn seeds. For the experiment it was used six batches of hybrid corn seeds with different levels of vigor and similar germination potential . After the initial characterization of the lots, it was evaluated the influence of temperature of 31, 34 and 37°C on germination, first count, length and dry mass of roots and shoots with lots of different levels of force. Data were subjected to analysis of variance and means were compared by Tukey test at 5%, in 3x6 factorial, which corresponded to three combinations of temperatures and six seed lots. The first count, the percentage of germination, length and dry mass, obtained at different temperatures along with the initial characterization data were submitted to the study of simple linear correlation at 5% significance. Temperatures of 31, 34 and 37°C proved to be efficient for the evaluation of maize seed vigor , with emphasis on the temperature of 34ºC which showed higher correlation with laboratory tests of the initial characterization of the lots and also with data emergency and the speed of the emergency field.(AU)

Morfologia de frutos, sementes e plântulas de Averrhoa bilimbi L. oriundas de dois estágios de maturação / Fruits, seeds and seedlings morphology of Averrhoa bilimbi L. derived from two stages of maturation

Este trabalho teve por objetivo descrever as características morfológicas de frutos, sementes e plântulas de Averrhoa bilimbi L. oriundas de frutos imaturos e maduros. Os frutos de A. bilimbi foram separados de acordo com a sua coloração em frutos imaturos e maduros. O registro das características morfológicas dos frutos, sementes e plântulas foram realizados por meio de ilustrações manuais, fotografias e descrições de todos os aspectos morfológicos. Para o estudo da morfologia da germinação e plântula, foram semeadas quatro repetições de 25 sementes sobre substrato papel mata-borrão e levadas ao germinador tipo B.O.D., regulado à temperatura constante de 30°C e regime de luz contínua. Os frutos tanto imaturos como maduros variaram apenas quanto ao tamanho, consistência e coloração, sendo as demais características comuns à espécie. As sementes dos frutos imaturos e maduros diferenciaram-se quanto à turgescência dos tecidos, assim como sua coloração, brilho e textura. A germinação é do tipo epígea e fanerocotiledonar, com início no sétimo dia e término no décimo quinto dia após semeadura, com a obtenção da plântula normal.(AU)

This study aimed to describe the fruits, seeds and seedlings morphological characteristics of Averrhoa bilimbi L. immature and mature fruits. The A. bilimbi fruits were separated according to color in immature and mature fruits. The record of fruits, seeds and seedlings morphological characteristics were performed by means of manual illustrations, photographs and morphological aspects descriptions. To study the germination and seedling morphology were take four replications of 25 seeds sown on blotter paper substrate and brought to B.O.D. adjusted in constant temperature 30°C under continuous light. The immature and mature fruits varied only in size, consistency and color, and other characteristics were common to the species. The seeds of immature and mature fruits could distinguished regarding the tissues turgor, as well as its color, luster and texture. The germination is phanerocotylar and epigeal, commencing on the seventh day and ending on the fifteenth day after seeding by obtaining normal seedling.(AU)

Relationship between germination and bell pepper seed structure assessed by the X-ray test

Alternative use of the X-ray test to evaluate seed quality has become increasingly diverse. This study was performed primarily to establish experimental procedures and verify the effectiveness of the X-ray test to detect damage or abnormalities in bell pepper (Capsicum annuum) seed structure associated with germination. Five seed lots each of hybrids Reinger and Sentinel were used. Two hundred seeds per lot were exposed to durations and intensities of X-radiation and visually classified into four categories according to the proportion between the area occupied by the embryo and endosperm in relation to the total cavity area in the internal seed structure, e.g. 0, 50%, 50-75% and 100%. The last category was subdivided into two others based on the occurrence of morphological abnormalities. Seed samples obtained from different X-ray categories were then submitted to germination test at 25ºC for 14 days and subsequently compared with results of the X-ray analysis. Exposure to a 10 kV radiation for 260 s was the most suitable X-ray dose for visualizing seed structure. Seeds in which the area of the internal cavity occupied by the embryo and endosperm varied from 50-75% produced abnormal seedlings or did not germinate. Full seeds (100% of the internal cavity area occupied) with abnormal structure usually originated defective seedlings. As a consequence, the classification of bell pepper seeds according to the proportion occupied by the seed content (embryo + endosperm) allowed a reliable estimation of the degree of seed physical integrity based on X-ray analysis and its association with germination performance.

Relationship between germination and bell pepper seed structure assessed by the X-ray test

Alternative use of the X-ray test to evaluate seed quality has become increasingly diverse. This study was performed primarily to establish experimental procedures and verify the effectiveness of the X-ray test to detect damage or abnormalities in bell pepper (Capsicum annuum) seed structure associated with germination. Five seed lots each of hybrids Reinger and Sentinel were used. Two hundred seeds per lot were exposed to durations and intensities of X-radiation and visually classified into four categories according to the proportion between the area occupied by the embryo and endosperm in relation to the total cavity area in the internal seed structure, e.g. 0, 50%, 50-75% and 100%. The last category was subdivided into two others based on the occurrence of morphological abnormalities. Seed samples obtained from different X-ray categories were then submitted to germination test at 25ºC for 14 days and subsequently compared with results of the X-ray analysis. Exposure to a 10 kV radiation for 260 s was the most suitable X-ray dose for visualizing seed structure. Seeds in which the area of the internal cavity occupied by the embryo and endosperm varied from 50-75% produced abnormal seedlings or did not germinate. Full seeds (100% of the internal cavity area occupied) with abnormal structure usually originated defective seedlings. As a consequence, the classification of bell pepper seeds according to the proportion occupied by the seed content (embryo + endosperm) allowed a reliable estimation of the degree of seed physical integrity based on X-ray analysis and its association with germination performance.

Effect of temperature and substrate on germination of Peltophorumdubium (Sprengel) Taubert seeds / Efeito da temperatura e do substrato na germinação de sementes de Peltophorum dubium (Sprengel) Taubert

Peltophorum dubium (Spreng.) Taub. is a species belonging to the family Fabaceae,and is known popularly as golden shower tree. Its wood has multiple uses in reforestationprograms and as an ornamental tree, and is also considered an endangered species, requiringstudies that assist in its preservation. The present work was conducted with the objective ofdetermine the ideal substrate type and temperature to perform germination and vigor testswith P. dubium seeds. The experiment was carried out at the Seed Analysis Laboratory(Centro de Ciências Agrárias, Universidade Federal Paraíba, Areia, Paraíba, Brazil), in acompletely randomized design. The treatments were distributed in a 4 x 6 factorial scheme;temperatures (constant temperatures of 25, 30 and 35°C; and alternate temperatures of 20-30°C) and substrate (paper towel, over blotting paper, in sand, in vermiculite, Bioplant® andPlantmax®) on four replications of 25 seeds. The following parameters were analyzed:germination percentage, germination speed index, first germination count, length and drymass of seedlings. The constant temperature of 30°C and 20-30°C alternate, and thesubstrates into sand and paper towel can be recommended for germination and vigor testsof P. dubium seeds. The temperature of 25°C should not be used in germination and vigortests of P. dubium seeds in any of the tested substrates.(AU)

Peltophorum dubium (Spreng) Taub. é uma espéciepertencente à família Fabaceae, conhecida popularmente como canafístula. A espécie pode serutilizada como ornamental e sua madeira tem múltiplos usos em programas de reflorestamento,é também considerada uma espécie em extinção, fazendo-se necessários estudos que auxiliem emsua preservação. Este trabalho teve como objetivo recomendar o substrato e a temperatura ideaispara condução de testes de germinação e vigor para sementes desta espécie. O experimento foirealizado no Laboratório de Análise de Sementes (Centro de Ciências Agrárias, UniversidadeFederal Paraíba, Areia, Paraíba, Brasil), em delineamento inteiramente ao acaso, com ostratamentos distribuídos em esquema fatorial 4 x 6 (temperaturas constantes de 25, 30 e, 35°C ealternada de 20-30°C e os substratos: papel toalha, sobre papel mata-borrão, entre areia, entrevermiculita, Bioplant® e Plantmax®), distribuídas em quatro repetições de 25 sementes. Foramanalisadas as seguintes características: germinação, índice de velocidade de germinação, primeiracontagem de germinação, comprimento e massa seca de plântulas. Recomendam-se paracondução dos testes de germinação e vigor das sementes de P. dubium os substratos entre areia oupapel toalha, na temperatura constante de 30°C e alternada 20-30°C. A temperatura de 25°C nãodeve ser utilizada para testes de germinação e vigor de sementes de P. dubium, em quaisquer dossubstratos utilizados.(AU)

Physiological potential of cauliflower seeds

The assessment of seed physiological performance is essential to provide consistent information to compose quality control programs conducted by seed companies and allow prompt decisions to reduce post-harvest and commercialization problems. This research was carried to evaluate the efficiency of different procedures to determine cauliflower seed vigor. Six lots of the cultivar Sharon were initially characterized by germination and seedling emergence, and subsequently subjected to traditional and saturated salt accelerated aging, controlled deterioration, electrical conductivity, and potassium leachate tests, in two evaluation times. The traditional accelerated aging (41ºC/48 h), the saturated salt procedure (45ºC/72 h), the controlled deterioration (moisture content adjusted to 20% or 22% and aging at 45ºC/24 h), the electrical conductivity (50 seeds/75 mL water and evaluation after 4 h) and the potassium leakage (25 seeds/50 mL of water and evaluation after 30 min) laboratory tests are sensitive to detect differences in the physiological potential of cauliflower seeds. However, those results did not relate to the percentage seedling emergence in greenhouse controlled conditions, as a consequence of the favorable conditions for emergence. However, the differences identified in the tests may be related to the ability of seed lots to perform in less favorable environments.

A eficiência da determinação do potencial fisiológico de lotes de sementes é essencial para a obtenção de informações consistentes, permitindo a composição de programas de controle de qualidade de sementes e a obtenção de informações consistentes para a redução de problemas pós-colheita e durante a comercialização. O objetivo desta pesquisa foi comparar a eficiência de diferentes procedimentos para a determinação do vigor de sementes de couve-flor. Para tanto, foram utilizados seis lotes do cultivar Sharon, caracterizados inicialmente pelos testes de germinação e de emergência de plântulas. Em seguida, conduziram-se testes de envelhecimento acelerado tradicional e com solução saturada de cloreto de sódio, deterioração controlada, condutividade elétrica e lixiviação de potássio, em duas épocas de avaliação. Os testes de envelhecimento acelerado tradicional, a 41ºC/48 h, e com solução saturada de cloreto de sódio, a 45ºC/72 h, de deterioração controlada (ajuste do grau de umidade para 20% ou 22%, 45ºC/24 h), de condutividade elétrica (combinação 50 sementes/75 mL de água/4 h) e de lixiviação de potássio (25sementes/50 mL de água/30 min) são suficientemente sensíveis para detectar diferenças no potencial fisiológico de sementes de couve-flor. No entanto, essas informações não se refletiram na percentagem de emergência de plântulas em ambiente favorável, mas podem ser úteis para identificar lotes com maior probabilidade de apresentar desempenho adequado quando ocorrem desvios das condições mais adequadas de ambiente.