Application of the YOLO framework in the classification of vigor levels in buffelgrass (Cenchrus ciliaris L.) seeds evaluated by tetrazolium test

Soybean [Glycine max (L.) Merr.] germination is routinely estimated from laboratory germination test results. However, differences in seed quality have caused variable germination performance both in the laboratory and in the field. The objective of this research was to determine ability of standard, tetrazolium, and cold germination tests to estimate average field emergence of mechanically damaged soybean seed. Damaged seeds were subjected to standard, tetrazolium, and cold germination tests and were planted in the field to determine field emergence and seed yield. Germination test accuracy was measured by analyzing the difference between field emergence and the germination test results.Increasing levels of mechanical damage significantly decreased percent laboratory germination in both years and generally decreased percent field emergence. The tetrazolium test indicated a significantly higher percent laboratory germination than did standard germination and cold tests, and the standard germination test resulted in significantly higher percent laboratory germination than did the cold test. The tetrazolium test was not sensitive in detecting recently induced mechanical damage, and the cold test showed more variability in percent laboratory germination.In 1975 the standard germination and cold test accurately estimated average field emergence within ± 8 and ± 12%. The tetrazolium test over‐estimated average field emergence from 0 to 20%. In 1976 the standard germination test estimated average field emergence within ± 12%, the tetrazolium test generally over‐estimated average field emergence from 0 to 18%, and the cold test under‐estimated average field emergence by 5 to 41%.

Frost damage in seed corn causes a significant decrease in seed quality. The tetrazolium (TZ) test has been used to identify types of physiological damage in several plant species, including frost damage in corn. Quantifying the amount of seed damaged by frost and the consequent loss of seed vigor are important for making management decisions. The current tetrazolium test procedures provide seed viability information but do not estimate seed vigor. In our project, the tetrazolium staining procedure was modified to allow separation of viable seeds into vigor categories. Vigor categories were defined based on Association of Official Seed Analysts (AOSA) recommendations, previous research, and current observations. The results from the tetrazolium test were compared with standard germination and saturated cold tests during the first 6 months of storage. The staining procedure aided in visual identification of frost damage. Although a strong correlation was found between seed viability as determined by the tetrazolium test, the standard germination test, and the saturated cold test, sorting seeds into vigor categories in the tetrazolium test did not improve the correlation between the tetrazolium test and the saturated cold test.

Himatanthus sucuuba é uma espécie arbórea amazônica, de importância na medicina popular devido às suas propriedades terapêuticas. As estimativas da viabilidade de sementes dessa espécie ainda são escassas, tornando-se necessário o desenvolvimento de testes rápidos que permitam a avaliação da qualidade das sementes. O objetivo deste trabalho foi adequar a metodologia para a realização do teste de tetrazólio e verificar a viabilidade das sementes armazenadas de Himatanthus sucuuba comparando os resultados dos testes de germinação e tetrazólio. Para o precondicionamento, as sementes foram imersas em água destilada por períodos de 4, 8, 12 e 14 horas a 25°C. Posteriormente, foi realizada a coloração dos tecidos, pela imersão em solução de tetrazólio 0,025%, 0,075% e 0,100% por 90 minutos a 40°C no escuro, e para a avaliação as sementes foram distribuídas em seis classes. Paralelamente, foram conduzidos testes de germinação em câmara BOD a 30°C, estabelecendo-se critérios para avaliação da viabilidade e do vigor. O delineamento experimental foi o inteiramente casualizado, e a comparação de médias foi realizada pelo teste de Tukey a 5% de significância. O teste de tetrazólio na concentração de 0,075% a 40°C durante 90 minutos mostrou-se eficiente para avaliar a viabilidade e vigor das sementes de Himatanthus sucuuba. A comparação entre a germinação (78%) e o teste de tetrazólio (70%), não mostrou diferença significativa entre eles, concluindo-se que sementes armazenadas por 14 meses permaneceram viáveis.

Summary The physiological quality of seeds of early and semi-early soybean cultivars may be lower than desired as a consequence of unfavorable climatic conditions occurring during the harvest period. The objective of this research work was to evaluate the effects of field weathering as well as the levels of mechanical damage at harvest on soybean seeds during storage, as determined by the tetrazolium (TZ) test. Seeds from two lots of each of three semi-early soybean cultivars (CD 214 RR, BRS 184, and Embrapa 48) with two different levels of initial vigour (high and medium) on the basis of the germination and accelerated ageing tests were stored in Mandaguari County, in the State of Parana, in storage facilities without environmental (temperature and relative humidity) control. Seed evaluations were performed using the tetrazolium test at 45 d intervals for a total of 225 d of storage. The parameters determined by the tetrazolium test were weathering (TZ class 3), and mechanical damage (TZ classes 6 to 8). It was concluded that weathering and mechanical damage injury increased substantially during storage, progressing linearly for the three cultivars studied and independent of the initial level of seed lot vigour. The classification of mechanical damage was only divided into two categories (immediate and latent damage) therefore further evaluations will be needed to accurately determine actual characteristics as well as their correlation with the loss of physiological quality of soybean seeds during storage.

In the Brazilian National System of Seeds and Seedlings, coffee seeds are evaluated by the germination or tetrazolium test. However, differences have been observed between the results of these tests in various studies, especially when the seeds have a lower level of quality. Given this situation, the aim of this study was to evaluate the correlation between historical data of results of the germination test and of the tetrazolium test in samples of coffee seeds using Generalized Additive Models for Location, Scale and Shape (GAMLSS). Historical data of results of the germination test and of the tetrazolium test of coffee seeds originating from different cultivars and different crop seasons were used. The zero-or-one inflated beta GAMLSS is suitable for fitting data from the germination test and from the tetrazolium test. The estimate of viability by the tetrazolium test varies according to the germination percentage class. There are greater GAMLSS correlations between the percentages of normal seedlings and of viability in the tetrazolium test for germination values above 70%, and low correlations below this value, showing that evaluation of coffee seeds based only on the tetrazolium test may not correspond to actual physiological performance.

Dormancy issues and lack of approved protocols have led to increasing use of the pregermination tetrazolium test to assess whether seeds of premium-priced, prevariety germplasm of native wildflower species are living and have the potential to germinate and develop normally under field conditions, that is, whether seeds are viable. A major concern is the limited amount of industrywide training on how to conduct and interpret results of tetrazolium (TZ) tests for the multitude of native species. Precise methods that yield uniform results are especially critical for testing of prevariety germplasm of native species given their high value and economic consequences of inaccurate test results. In preliminary work, we observed that embryos extracted from intact seeds of native Coreopsis species subjected to TZ testing were viable if they were turgid and appeared normal and were stained pink, red, or were pure white with or without the radicle tip stained pink to red. In this study, we conducted an in-depth analysis of TZ testing of intact seeds of prevariety germplasm of four native Coreopsis species to: 1) verify our preliminary conclusions; and 2) to determine if staining could be improved by preconditioning or gibberellic acid (GA 3 ) because relatively low percentages of embryos of intact seeds stained pink or red. In addition, we evaluated two other methods to assess viability: the excised embryo test and emergence tests in soil and a soilless medium under ambient conditions. We confirmed that embryos extracted from intact seeds subjected to TZ testing were viable provided that embryos were turgid and appeared normal and were stained pink, red, or were pure white ± a pink to red radicle tip. Embryo staining was not consistently improved by moist preconditioning or GA 3 . Results of pregermination TZ tests of intact seeds and/or germination plus postgermination TZ tests of intact, nongerminated seeds were not consistently accurate and/or uniform across all species and seed lots, issues usually encountered in seed lots that were relatively dormant or of poor quality, and in postgermination TZ testing of seed lots with relatively low dormancy. Moreover, these issues are likely to be encountered even with standard TZ testing protocols given the widely accepted challenges of accurately interpreting TZ tests of native species in general. The most precise, uniform method of assessing viability was the excised embryo germination test because all viable seeds germinated, results were easy to interpret so the likelihood of false-positives or -negatives was nil, and results were very uniform across replications. Emergence tests under ambient conditions substantially underestimated viability. In summary, the high cost of prevariety germplasm seeds of native Coreopsis species, inherent genetic and phenotypic variability, and unknown dormancy characteristics warrant the use of the embryo excision test for determining viability and for increased sample sizes, especially for any tests involving TZ.

The viability of T. aurea seeds is evaluated through the germination test, taking 21 days, which makes it difficult to obtain quick information about the viability of its seeds. In this context, using the tetrazolium test as an evaluation method would be appropriate because it provides faster and more reliable information for several species. In view of the above, the objective of this study was to adapt the tetrazolium test methodology to evaluate the viability of T. aurea seeds. Initially, the imbibition curve was constructed to determine the appropriate hydration period for the seeds and the germination test was conducted, both for evaluating the initial quality and for comparison with the tetrazolium test results. For the tetrazolium test, the seeds were hydrated for 24 hours, then their coats were removed and the seeds were immersed in tetrazolium solutions. The concentrations used were 0.05, 0.075 and 0.1% for three staining periods 2, 4 and 6 hours, at 35 and 40 °C, in the absence of light. The experimental design was completely randomized in a 3 x 3 + 1 factorial scheme (three concentrations of tetrazolium solution x three staining periods + one control = germination test) with four replicates of 25 seeds. Tetrazolium test was adequate to evaluate the viability of T. aurea seeds using the concentration of 0.05% for four hours at 40 °C.

Pterogyne nitens Tul., also known as brave peanut, is a native tree species, with economic and ecological importance, occurring from the Northeast to the South of Brazil. For most forest species, the standard germination test requires a relatively long time to obtain results, which is why tests such as the tetrazolium test have been widely used, as they are a quick and low-cost test. Therefore, the objective of the present work was to establish the most appropriate procedure for conducting the tetrazolium test to evaluate the viability of Pterogyne nitens seeds. The trial was conducted at the Phytotechnics Laboratory, at the Engineering and Agricultural Sciences Campus, at the Federal University of Alagoas, Rio Largo, AL, Brazil. To define the most appropriate methodology for the tetrazolium test and ensure the viability of Pterogyne nitens seeds, a completely randomized experimental design was used, in a 2x3+1 factorial scheme, with two concentrations of the tetrazolium solution, three periods of coloring, plus a control treatment represented by the germination test, with four replications of 25 seeds. Only the cotyledons containing the embryo were placed in 50 mL plastic cups, and immersed in a solution of 2,3,5-triphenyl tetrazolium chloride salt, at concentrations of 0.05 and 0.075%, for staining periods of 2. 4 and 6 hours, in a Biochemical Oxygen Demand (B.O.D.) chamber at 30 ºC in the dark. For the germination test, the seeds were placed equidistant in plastic boxes with blotting paper and a volume of water equivalent to 2.5 times the weight of the substrate, and placed in a B.O.D. chamber. regulated at 30 ºC and a 12-hour photoperiod. Based on tissue color and health standards, seeds whose embryonic axis was pink in color were classified as viable, and seeds with a discolored embryonic axis or yellow or intense red color were classified as non-viable. In general, the results of the percentage of viable seeds of Pterogyne nitens obtained in the tetrazolium test presented values below 78%, showing significant differences in relation to the germination test with 95%, except for the concentration of 0.05% for 6 hours presenting 90% viability. The tetrazolium test proved to be efficient in evaluating the viability of Pterogyne nitens Tul. seeds, being recommended to be immersed in a tetrazolium solution at a concentration of 0.05% for 6 hours.

Xylopia aromatica is a native species from Brazil's "Cerrado", recommended for restoration ecology and also as a medicine. Its seeds have embryos with morphophysiological dormancy, making nursery propagation difficult. The objective of this study was to verify the efficiency of X-ray and tetrazolium tests for evaluating the viability of three seed lots, stored for different periods. All seeds were X-rayed (13 kV, 350 seconds) and samples used for tetrazolium and germination tests. In the tetrazolium test, seeds were submitted to six treatments at two temperatures (25 and 30 °C) with imbibition in distilled water and immersion in three concentrations of tetrazolium solution (0.5, 0.75 and 1%) at the two imbibition temperatures. Seeds for the germination test were placed for imbibition in distilled water and a 500 ppm Promalin® (6-Benzyladenine + GA4 + GA7) solution and later sown in sterilized sand. The embryo could not be observed with the X-ray test. However, those seeds observed with an undamaged endosperm did not differ in the percentages of seeds with firm and stained endosperms observed in the tetrazolium test for all the lots. The tetrazolium test is efficient for evaluating seed viability, principally if imbibed at 30 °C and immersed in a 0.5% solution at 30 °C.

In this study the possibilities of using the tetrazolium and germination tests for the detection of irradiation of wheat were investigated. One durum and two bread wheat samples were irradiated at 0.5, 1.0, 2.5, 5.0 kGy levels using 60Co source. It is concluded that the tetrazolium test is insensitive to detect irradiation in the wheat samples at these levels of irradiation. However, it seems that the germination test can be used as a qualitative test to detect the irradiated wheat samples. Abnormal germination was observed at all levels of irradiation. It is an economical method which reveals the results in the fourth day of germination.

Commiphora leptophloeos, a native Caatinga species with economic and medicinal potential, faces propagation challenges due to seed dormancy and extractive use. The germination test, the official method for seed quality assessment, is time-consuming, whereas the tetrazolium test (TZT) offers a rapid alternative for determining seed viability. This study aimed to establish and validate a TZT protocol for C. leptophloeos seeds. Seeds collected in 2025 were extracted after natural fruit drying and then stored in a cold chamber. The germination test was conducted with seeds without pyrenes at 30 °C. For the TZT, a completely randomized design was used in a 6 × 4 factorial scheme (six TZT concentrations × four immersion times), with adjustments in seed preparation and staining procedures. Higher concentrations (0.5% and 0.75%) combined with shorter immersion periods (2 h) provided the best results, especially 0.75% for 2 h, which yielded 89% viability. Very low concentrations combined with short periods resulted in little or no staining. Compared with the germination test (35%), the TZT showed greater sensitivity in detecting viable seeds. We conclude that the TZT is highly efficient for assessing the viability of C. leptophloeos seeds, with optimal responses at 0.5–0.75% TTC and 2–4 h immersion periods, and represents a strategic tool to support the conservation and sustainable use of this species.

O Brasil tem muitas áreas com Panicum maximum Jacq, sendo produtor, consumidor e exportador de suas sementes. Contudo, a qualidade das sementes produzidas é duvidosa. O teste de germinação não é eficiente para estimar a viabilidade de sementes desta espécie, principalmente logo após a colheita, quando se tem alto percentual de sementes dormentes, sendo necessária a realização do teste de tetrazólio. Com o objetivo de avaliar as metodologias mais utilizadas na condução do teste de tetrazólio determinou-se a viabilidade de quatro lotes da cultivar Tanzânia, com diferentes qualidades fisiológicas e intensidades de dormência, através das seguintes metodologias e concentrações da solução de 2,3,5 trifenil cloreto tetrazólio: 1,0% (conforme metodologia prescrita pela International Seed Testing Association - ISTA); 0,2% com descarte de metade da sementes e 0,1% sem descarte de uma metade da semente. Como referencial, o teste de germinação foi realizado com e sem tratamento para superação da dormência, sendo as avaliações realizadas em quatro épocas trimestrais. Como tratamento para superação da dormência utilizou-se a temperatura de 42° C durante 72 horas. Não houve diferenças significativas entre as diferentes metodologias utilizadas para o teste de tetrazólio. A visualização da estrutura embrionária foi facilitada quando foram avaliadas as duas metades das sementes. Não houve diferença siginifcativa entre a viabilidade, pelo teste de tetrazólio, e a germinação de lotes sem sementes dormentes. O tratamento para superação da dormência não foi eficiente para todas as sementes e prejudicou a germinação, quando não havia mais dormência. Os lotes que não possuíam sementes dormentes não apresentaram diferenças significativas entre os resultados dos testes de germinação e tetrazólio.

As sementes de Brachiaria brizantha apresentam dormência, principalmente quando recém colhidas, o que torna o teste de germinação ineficiente para avaliar a viabilidade, sendo necessária a realização do teste de tetrazólio. Visando comparar as metodologias mais utilizadas na condução do teste de tetrazólio nestas sementes, determinou-se a viabilidade de quatro lotes da cultivar Marandu, com diferentes qualidades fisiológicas e intensidades de dormência, em cinco épocas trimestrais. O teste de tetrazólio foi conduzido com as seguintes concentrações de 2,3,5 trifenil cloreto tetrazólio: 1,0% (conforme metodologia prescrita pela International Seed Testing Association - ISTA); 0,2% e 0,1% (sem descarte de uma metade da semente). Como teste referencial foi realizada a germinação sem e com tratamento para superar a dormência, utilizando a escarificação em ácido sulfúrico. Os resultados dos testes de tetrazólio obtidos com as menores concentrações não diferiram da metodologia recomendada pela ISTA, mas facilitaram a interpretação, devido a melhor visualização da estrutura embrionária. O tratamento para superação da dormência não foi eficiente para todas as sementes e prejudicou a germinação das não dormentes. Os testes de tetrazólio e de germinação podem ser considerados como complementares e, em conjunto, permitem avaliar a qualidade fisiológica das sementes de Brachiaria brizantha.

ABSTRACT: Prior to commercialization, seeds of peach palm (Bactris gasipaes Kunth) have to undergo the germination test, whose well-established methodology takes 120 days. Due to their recalcitrant behavior, the seeds have short longevity when stored (around 30-45 days), which makes it challenging to select the most viable ones for marketing. This study aimed to determine a methodology for the tetrazolium test to be carried out in peach palm seeds, in order to fast deliver results that can be correlated to the germination test. Different forms of pre-conditioning, preparation, and staining were investigated via moisture content, germination, and tetrazolium tests, so as to define the vital parts of the seed and sort out the viability classes. For the seed lot under study, the tetrazolium test delivered results supported by the germination test when the following procedures were adopted: pre-conditioning by water submersion (20 °C for 24 h), longitudinal cut adjacent to the embryo, and half-seed immersion (embryo + endosperm) in a 1.0% tetrazolium solution for 4 h at 30 °C. Having fulfilled these criteria, it became possible to separate the peach palm seeds into two classes (viable or non-viable).

Abstract: Rapid tests have been essential to evaluate the physiological potential of seeds and the tetrazolium test is one of those which have been used by seed companies. The objective of the study was to establish the procedure for the tetrazolium test in Libidibia ferrea (Mart. Ex Tul.) L.P. Queiroz var. ferrea seeds. For this, three tetrazolium solution concentrations (0.05, 0.075 and 0.1%) and three staining periods (1, 3 and 6 hours) at temperatures of 35 to 40 °C were tested. The seeds were also evaluated by the germination test, whose result was compared with viability by the tetrazolium test. The experimental design was completely randomized in a factorial design 3 x 3 + 1 (three concentrations x three periods + a control = germination test) for each temperature. Viable seeds in the tetrazolium test were compared by Tukey’s test (p ≤ 0.05), while the comparison between the viable seeds with germination test was carried out by Dunnett’s test (p ≤ 0.05). It is recommended that the tetrazolium test for L. ferrea is carried out at a concentration of 0.05% for three-hour staining under 35 °C or 40 °C.