Tetrazolium Viability Test Research Articles

Aportes a la morfología de semillas de Hibiscus cannabinus L. y ajuste de la prueba de tetrazolio para estimar viabilidad y vigor

Hibiscus cannabinus L. is an annual species cultivated for its fibers. The morphological description of the seeds of the cultivars ‘Endora’ and ‘Tainung' 1’ was broadened, a tetrazolium test procedure was adapted and adjusted, and the embryos were classified according to their viability and vigor. Cells from the seed coat layers participate in the seed coloration and ornamentation. The imbibition cap and the isthmus were identified, and their function wasanalyzed. Lipids and proteins were recognized in the mesophyll of cotyledons and the absence of areoles in the epidermis. Using the tetrazolium test, staining patterns were established to classify the seeds according to their viability. Both cultivars presented acceptable viability values. The germination test supported the proposed methodology for tetrazolium. Novel contributions are made to seed morphology, and structure-function relationships for water intake are proposed. The seeds of both cultivars share the morphological characteristics that are fundamental to the establishment of evaluation criteria in the tetrazolium biochemical test. The adapted tetrazolium viability test protocol allowed the seeds classification as either viable into three categories (high, medium, and low vigor) and non-viable seeds.

Do storage of Eugenia stipitata seeds affect their germination and efficacy of the tetrazolium viability test?

Eugenia stipitata is a fruit species from the Amazon that is important in traditional medicine due to its therapeutic properties. Estimates of seed viability in this species are still scarce, and it is necessary to develop rapid tests to determine the quality of the seeds. The aim of this study was to determine the applicability of the tetrazolium test to estimate viability and germination in seeds of E. stipitata with and without storage. The design was completely randomised in a 2 x 2 factorial scheme with 10 replications. The results of the tetrazolium and germination tests show that seeds of E. stipitata lose their viability when stored for six months in water at ambient temperature. Neither small nor large seeds stored for six months in water at ambient temperature are recommended for use with the tetrazolium test. Small, freshly harvested, unstored seeds show a germination potential of 100%. The tetrazolium test is efficient in determining the viability of small and large seeds of Eugenia stipitate with no storage.

Effectiveness of fish assemblage as seed dispersers in Amazon oligotrophic flooded forests

AbstractIn tropical and highly diverse systems, Seed Dispersal Effectiveness (SDE) is a very useful approach to investigating the role of seed dispersers in one of the most important and complex phases of plants by analysing the quantitative (QC) and qualitative (QL) components of the seed dispersal process. Although fishes are recognized as an important guild of frugivores in flooded environments, we still know very little about the dispersal effectiveness performed by this group. Our study evaluated two quantitative subcomponents of effectiveness, where we used: (a) the volume of intact and crushed seeds found in the stomach and intestine of fish (QC1), and (b) the total number of tested and viable seeds (QC2). From these subcomponents, a two‐dimensional landscape of effectiveness was generated and a fish species was ranked according to the quantitative component of the SDE. Eight species of fish consumed 1054 seeds belonging to 16 plant species. Sphinctanthus striiflorus, Corynostylis pubescens, Connarus sp. and Piper sp., were the most abundant plant species in fish's diets, totalling 95% (N = 983) of the seeds consumed. We used a tetrazolium viability test protocol and about 678 (85%) of the 797 seeds tested were viable and 119 (14.7%) were unviable; the viability test was inconclusive for less than 1% of the seeds. Our findings showed that, as seen in other effectiveness studies with terrestrial vertebrate dispersers, fish species also have different degrees of effectiveness. Additionally, we pointed out that the fish species more specialized in the consumption of fruits and seeds were quantitatively more effective dispersers, while species with lower SDE corresponded to generalists that just occasionally consume seeds. We suggest that high‐diversity fish assemblages allow for greater complementarity in the seed dispersal interaction, which can potentially favour the recruitment of plant species via ichthyochory.

Improvement of the methodology of the tetrazolium test using different pretreatments in seeds of the genus Epidendrum (Orchidaceae)

Abstract: The aim of the present study was to determine the most suitable pretreatment to enhance the tetrazolium test in seeds of the Epidendrum genus. Initially, mature capsules were harvested at El Escorial village, in the municipality of Pamplona, Colombia. Subsequently, the seeds were subjected to five pretreatments: deionized water, 0.5% NaClO, 1.0% NaClO, 10.0% sucrose and a control group. Using the syringe method with cloth filter, the seeds were rinsed with distilled water and subjected to two concentrations of tetrazolium solution (0.25%, 1.0%) and three exposure times (6 h, 24 h and 48 h). Finally, the tetrazolium viability test results were correlated with the in vitro germination test. It was found that the use of deionized water improves the efficiency of the tetrazolium test in seeds of Epidendrum fimbriatum and E. microtum; as in seeds of E. elongatum when using 1.0% tetrazolium for 24 h. Similarly, a high correlation was found between viability and germination, using deionized water and 10.0% sucrose, with homogeneous results with each other.

Establecimiento de un método eficiente de estandarización de la germinación in vitro de Moringa oleifera (Moringaceae)

Antecedentes y Objetivos: Moringa oleifera es fuente de fitoquímicos con aplicación potencial en medicamentos. Su uso medicinal, sobre todo de las hojas, es reconocido mundialmente; se les atribuye la presencia de compuestos bioactivos funcionales. El objetivo de este trabajo fue estandarizar la germinación in vitro de M. oleifera en biorreactores de inmersión temporal utilizando distintos medios de cultivo.Métodos: Las semillas se sembraron con y sin testa, en medios basales líquidos compuestos de agua (control) y sales de Murashige y Skoog (MS) en su concentración original o diluido al 50 y 25%, con 0, 15 y 30 g l-1 de sacarosa. Se evaluaron los porcentajes de germinación, indicadores de vigor y crecimiento en plántulas.Resultados clave: En las semillas con testa se obtuvo un 23.33±5.77% de germinación en un solo tratamiento sin lograr evaluar los parámetros propuestos. Se complementaron estos resultados con la prueba de viabilidad de tetrazolio de las semillas no germinadas, registrando un 34.16±18.73% de viabilidad. La remoción de la testa y medio de cultivo líquido favorecieron la germinación. El mayor porcentaje de germinación, capacidad germinativa y coeficiente de uniformidad, así como mayor desarrollo foliar, relación de biomasa aérea y radical, incremento de peso seco de material vegetal por unidad de tiempo, al igual que la acumulación de masa seca, se obtuvieron con MS como medio basal.Conclusiones: Para la estandarización de la germinación in vitro de Moringa oleifera se recomienda la remoción de la testa y la utilización de MS como medio basal, ya que aceleran el proceso y posibilitan obtener plántulas que podrán ser utilizadas para experimentos de regeneración indirecta y/o directa para un escalado masivo de germoplasma.

Comparative Studies on Cotton Seed Germinability with Tetrazolium Viability Test and X-ray Contrast Methods

Seed viability testing provides valuable information for assessing seed lot germinability. However, most testing methods require destruction of seed prior to test. Because the dissected seeds for viability test cannot be used further evaluation, the nondestructively X-ray photography technique that can be applied for the evaluation of seed quality has been developed. In order to know the validity and accuracy of X-ray photography technique in seed evaluation test that conducted to remove the abnormal seed from a seed lot, we have compared the results from tetrazolium viability test, germination test and X-ray contrast method in cotton. Metallic salts treatment increased the efficiency of X-ray photographic method by enhancing the penetration of X-ray in abnormal or damaged seeds rather than normal seeds that have strong and well-organized tissues in seed. Cotton seeds presoaked for 16 hr in distilled water followed by soaking into metallic salt solution (5% NaI in water) for 60 min were easily classified seeds into dead seed and viable seed based on the radiography images obtained by X-ray radiation. We concluded that soft X-ray photography was reliable to find out the various defective characters due to heat and mechanical damage of seeds.

Germination and viability of wild sunflower species achenes stored at room temperature for 20 years

Storage times and conditions affect the longevity of stored seeds. Achenes of two wild annual sunflower species, Helianthus annuus (common wild sunflower) and H. petiolaris (prairie sunflower), stored at room temperature (20 to 22°C) at a relative humidity of approximately 22% in a bell jar in the laboratory for 20 years were evaluated for germination and viability. The efficacy of using gibberellic acid (GA3) as a germination medium to overcome dormancy was also tested. Germination of wild H. annuus achenes stored for 20 years was 13%, while H. petiolaris had only 1.5% germination. Germination of fresh achenes at harvest was 34.7% for H. annuus, and 18.5% for H. petiolaris. Stored wild H. annuus achenes had 90% positive staining using the tetrazolium viability test, while H. petiolaris had 80.2% indicating that the achenes were alive, but dormant. Treating scarified wild achenes with 1 mM GA3 for one hour increased germination of the stored wild H. annuus achenes from 13% to 88%, and H. petiolaris from 1.5% to 85%. This indicates that the wild sunflower achenes stored at less than optimal conditions for long periods are dormant and should not be discarded as dead. This information will be useful for curation of wild sunflower germplasm.

The root microtubule cytoskeleton and cell cycle analysis through desiccation of Brassica napus seedlings

Desiccation tolerance (DT) of orthodox seeds is reduced upon their germination. The main aim of this study was to estimate the range of rape seedling DT by examining the consequences of desiccation on the distribution, stability and orientation of microtubules in diverse cells. Using different parameters, such as relative water content (RWC), the tetrazolium viability test and electrolyte leakage, it has been demonstrated that a small percentage decrease in relative humidity can cause irreparable changes in membrane permeability, as well as in nuclear structure and microtubule cytoskeleton stability. Seedling root tips survived when exposed to low desiccation stress intensity, but small changes in microtubule behavior were observed. Cortical microtubules formed thick arrays, especially near the plasma membrane. Water loss also resulted in a reduction of the mitotic activity. More rapid desiccation caused microtubule depolymerization. Occasionally, abnormal tubulin aggregates were visible. Cell divisions were not detectable under these conditions. Due to the observable microtubule defects, the hypersensitivity of the microtubule cytoskeleton might be a useful and simple parameter for estimating environmental stress intensity.

Posidonia oceanica seeds from drift origin: viability, germination and early plantlet development

Abstract Recruitment of Posidonia oceanica from seeds is infrequent owing to the rare and unpredictable occurrence of sexual reproduction. However, in years of high reproductive success, ample supplies of seeds become available in drifting fruit; this could be a useful source of material for seabed restoration. In this study we introduce and combine viability tests and culture procedures for evaluating this material. Three different groups of collected fruits representing a phenological or maturation sequence were tested for seed viability with tetrazolium. We also examined the effects of storage on the germination and development of seedling root and shoot systems. The younger groups showed good (67–86%) germination and survival, with the tetrazolium viability test proving useful for predicting these processes. However, although a strong correlation between fruit and seed weight was observed, higher values of these parameters did not confer greater germination capacity. The seeds of fruits collected late in the season were more developed and plantlet roots and shoots grew faster under culture, but survival after 4 weeks was reduced (40%). Under the conditions tested, viability was highly reduced and there was no final seedling survival following storage.

Germination responses of Sporobolus ioclados: a saline desert grass

Sporobolus ioclados (Nees ex Trin.) Nees (Poaceae), a halophytic grass distributed in coastal and inland regions of Pakistan, is a potential forage crop which could be grown in the degraded saline soils of the Indus plain and coastal areas. Greatest germination was obtained in non-saline control and it was linearly reduced with increases in salinity to 500 m M NaCl. Variation in temperature substantially affected germination in both the saline and non-saline treatments. At the optimal temperature regime of 20:30°C, S. ioclados seeds showed 93% germination at 0 m M NaCl and 18% germination at 500 m M NaCl, respectively. In all other temperature regimes, only 50% of the seeds germinated in 0 m M while none germinated at 500 m M NaCl. Rate of germination decreased with an increase in salinity at all temperature regimes but comparatively higher rates were obtained at 20:30°C. Seeds showed a low recovery response when transferred to distilled water after 20 days of exposure to salinity and tetrazolium viability test showed that most of the un-germinated seeds were dead. The present study showed that if the seed is protected from salinity and temperature stress during storage in the soil, it could germinate during monsoon rains.

Previous Grazing or Clipping Affects Seed of Indian Ricegrass

Previous heavy grazing for more than 50 years, compared with protection from livestock grazing, in the semi-arid area of Chaco Canyon in the southwestern United States did not result in any significant decrease in seed production potential of Indian ricegrass [Oryzopsis hymenoides (Roem. and Schult.) Ricker]. There also were no significant differences in seed production between grazed and ungrazed collections of Indian ricegrass from the Chaco Canyon study site when transplanted and grown in a common garden. This indicated that long-term protection from livestock grazing probably had not genetically (ecotypically) altered seed production potential. Both grazed and ungrazed transplants of Indian ricegrass differed in seed production from the cultivars 'Paloma' and 'Nezpar'. Nezpar produced the greatest seed yield (312 kg/ha), while Paloma had the lowest yield (78 kg/ha). Defoliation about 1 June over a 2-year period reduced seed production and nitrogen fertilization did not increase seed yield. Previous grazing history had little effect on seed germination, but there were significant differences in germination among some collections and cultivars of Indian ricegrass. Germination was less than 5% for all entries. A tetrazolium viability test showed that seed of native strains were more viable than those of Paloma. Dormancy is a troublesome, but desirable, trait of Indian ricegrass seed for use in droughty areas.

Germination behaviour of seeds of the New Zealand speciesFuchsia excorticata, Griselinia littoralis, Macropiper excelsum, andMelicytus ramiflorus

Abstract Germination rates, percentage germination success, and phenomena related to germination delay for two provenances each of seeds from freshly collected fruit of Fuchsia excorticata, Macropiper excelsum, and Melicytus ramiflorus, and one provenance of Griselinia littoralis were determined. Normally the seeds of all four species are bird-dispersed. The experimental treatments simulated natural conditions that the seeds might experience after dispersal (well-lit; in the dark; in the fleshy pericarp tissues; on soil). A tetrazolium viability test was also performed. In the standard (cleaned, moist, well-lit) treatment, seeds of each of these species germinated rapidly in summer — early autumn, with high success. The dark treatment seeds of Fuchsia and Griselinia germinated more slowly than those in the standard treatment and the success was lower. Seeds surrounded by pericarp tissues either did not germinate (Griselinia), or germinated slowly, with low success (the other three species). Fewer seeds ge...

VIABILITY AND GERMINATION TESTS OF FRINGED GENTIAN, GENTIANA THERMALIS (O. KUNTZE) ILTIS

Fringed gentian, Gentiana thermalis (O. Kuntze) Iltis is an attractive wildflower, that may be used as a fall flowering ornamental. This species has received limited attention in terms of seed viability and germination. Seeds were subjected to a tetrazolium viability test that involved imbibition for 24 hours at 22C. No embryos in any line tested were stained. However, imbibition at 3C for up to 4 weeks followed by staining at 22C resulted in significant levels of positive viability, as indicated by embryo staining. A germination study indicated that stratification was necessary for germination, with 6 weeks chilling giving better results than 0 or 3 weeks. However, the number of seeds germinated was less than expected, given the results of the tetrazolium test.

Effect of Tilletia indica Infection on Viability, Germination, and Vigor of Wheat Seed

The effect or Karnal bunt (T.i.) infection on viability, germination and vigor of wheat seed was determined using the topographical tetrazolium viability test, the rolled paper towel germination test, and the accelerated aging vigor test. Infection had very little effect on seed viability, irrespective of the age of the seed, while germination of infected seed appeared to depend upon the wheat cultivar and age of the seed. In contrast, there was a signigicant reduction in vigor of infected seed. Infected seeds would therefore appear to have a lower survival rate in storage compared to healthy seeds of the same seed lot

Seed Dormancy in Green Needlegrass1

SynopsisDormancy was present in seeds harvested at all stages of maturity. The tetrazolium viability test gave an accurate measure of the germination potential of a seed lot. A laboratory germination procedure was developed which induced practically complete germination and equaled tetrazolium readings.