scholarly journals Explanining the vigor (relative and absolute) in seeds: the biological meaning behind the mathematician

2020 ◽  
Vol 36 ◽  
Author(s):  
Vanderley José Pereira

Seed vigor is the totality of all properties that determine a rapid and uniform emergence and development of normal seedling under a wide range of conditions. However, the physiological quality within a seed lot is not  homogeneous, generating a quality gradient between seeds. Thus, the vigor expressed by the final percentage of normal seedlings tends to underestimate the quality of the batch, considering the total number of seeds. One possible method for correcting such an effect would be to weight vigor by germination, generating an index called relative vigor. The index reflects the “success” of viable seeds in maintaining their potential under stress. In this context, this review article proposes the possibility of using a new measure for vigor and new interpretation of relative vigor, as well as providing the mathematical basis for its use.

2005 ◽  
Vol 17 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Sttela Dellyzete Veiga Franco da Rosa ◽  
Delacyr da Silva Brandão Júnior ◽  
Édila Vilela de Resende Von Pinho ◽  
André Delly Veiga ◽  
Luiz Hildebrando de Castro e Silva

Desiccation tolerance in seeds depends on the species, development stage and drying conditions, especially the water removal rate. Coffea seeds are considered of intermediate performance, because they tolerate relative dehydration compared to orthodox seeds and are sensitive to low temperatures. The objective of this study was to verify the effect of different drying rates on the viability and storability of Coffea canephora seeds. A complete randomized experimental design was used, in a factorial 3 x 5 x 2 design, with three drying rates (fast, intermediate and slow), five final mean water contents after drying (51, 42, 33, 22 and 15 %) and two storage temperatures (10 and 20°C). The germination and seed vigor assessments, using radicle protrusion, cotyledon leaf opening, seedling emergence and emergence speed index, were performed shortly after drying and after two and four months storage. It was observed that with reduction in the water content there was reduction in the germination values and seed vigor, for all the drying rates. The greatest reductions in physiological quality occurred when the seeds were dried quickly and the best results were obtained at the intermediate drying rate. There was an effect of drying rate and storage temperature on the physiological quality of the seeds, and lower germination and vigor values were observed in seeds with lower water content stored at 20°C. C. canephora seeds were tolerant to desiccation down to 15 % water content and can be stored for four months at 10°C. A temperature of 20ºC can be used to store C. canephora seeds, as long as the water content is not reduced to values below 22 % water content.


2021 ◽  
Vol 43 ◽  
Author(s):  
Carolina Pereira Cardoso ◽  
José Henrique Bizzarri Bazzo ◽  
Jéssica de Lucena Marinho ◽  
Claudemir Zucareli

Abstract: Initial seed vigor and sowing density interact in establishment of plants in the field, and can thus affect expression of the plasticity of the wheat crop and the yield and physiological quality of the seeds produced. The aim of this study was to evaluate the effect of seed vigor levels in combination with sowing densities on the yield and physiological potential of wheat seeds. The cultivars BRS Gralha-Azul and BRS Sabiá were used in a randomized block experimental design in a 2 × 4 factorial arrangement, with four replications. The treatments consisted of seeds of high and low vigor and four sowing densities (150, 250, 350, and 450 seeds.m-2). The following evaluations were made: seed yield, germination, first germination count, seedling length, seedling dry matter, accelerated aging, emergence speed index, and seedling emergence in sand. An increase in sowing density favors the seed yield of both cultivars; however, it reduces the vigor of the seeds produced by the cultivar BRS Gralha-Azul, especially of the seeds produced by plants originating from high vigor seeds. For the cultivar BRS Sabiá, an increase in sowing density decreases the germination performance of seeds produced by plants originating from low vigor seeds.


2009 ◽  
Vol 33 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Daniel Santos Pinho ◽  
Eduardo Euclydes de Lima e Borges ◽  
Viviana Borges Corte ◽  
Luiz Carlos Bhering Nasser

The aim of this experiment was to evaluate the effect of storage temperature on the viability and vigour of A. peregrina seeds. Seeds of A. peregrina harvested in Viçosa-MG, in September 2005 were used. The seeds were stored in the Laboratory of Forest Seeds Analysis (LASF) of the Universidade Federal de Viçosa (UFV), in a cold chamber, under approximately 5ºC over150 days. The seeds were stored under 20ºC for 150 days more. Seed moisture was determined after oven-drying at 105 ± 3ºC for 24 hours. The seeds were analyzed monthly using germination, tetrazolium and electrical conductivity tests and Osmopriming during 300 days, with four repetitions of 25 seeds. A. peregrina seeds kept a constant percentage of germination and viable seeds under the tetrazolium test for five months of storage, under either 5ºC and 20ºC. The electrical conductivity test showed significant differences in relation to the storage period, proving to be more sensitive than the standard germination test. Seed priming in PEG -0,4 MPa solution was not efficient in recovering the viability and vigor of the stored seeds at 5ºC and 20ºC.


2021 ◽  
Vol 29 ◽  
pp. 28-35
Author(s):  
Letícia Betânia Xavier Dias ◽  
Pedro Afonso de Melo Queiroz ◽  
Thaís Cardoso de Castro ◽  
Marco Antonio Moreira de Freitas ◽  
Érica Fernandes Leão-Araújo ◽  
...  

Our objective was to evaluate the occurrence of mechanical damage in chickpea seeds with the combination of two harvester speeds (2.5 and 3.5 km.h-1) and three adjustments for rotor rotation speeds (500, 700, and 850 rpm). Harvesting was carried out in a seed production field. Seeds were evaluated for purity, germination (G), first count (FC), germination speed index (GSI), hypochlorite, electrical conductivity, and tetrazolium tests. There was an effect of harvester speeds on seed physiological quality for the first count (FC), germination (G), germination speed index (GSI), especially when combining with high rotor rotation speed. In these cases, the speed of 2.5 km.h-1 resulted in lower values. This harvester speed also had worse results when combining with 850 rpm for purity and hypochlorite tests. The tetrazolium test was not efficient in identifying differences in seed quality. There was no significant interaction between harvester speeds and rotor rotation speeds for the conductivity test. Evaluating the harvester speed’s isolated effect (3.5 km.h-1), we identified problems in seed vigor due to the higher value of exudates in the electrical conductivity test. Low harvester speed (2.5 km.h-1) associated with high rotor rotation speeds (700 and 850 rpm) causes a reduction of the physical and physiological quality of seeds.


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4047
Author(s):  
Thiago Alberto Ortiz ◽  
Aline Moritz ◽  
Lúcia Sadayo Assari Takahashi ◽  
Mariana Ragassi Urbano

Germination test is used to assess the physiological quality of seeds; however, since it is carried out under ideal conditions, this test has not been shown sufficient for this purpose. Instead, it is possible to use vigor tests, although the lack of standardized methodologies has reduced their applicability and reproducibility. Thus, this study aimed to develop methodologies for conducting tests of germination, accelerated aging, and electrical conductivity for the evaluation of the physiological quality of pitaya seeds. For this purpose, seeds from ripe Hylocereus undatus fruits were used. A completely randomized experimental design was used with four replications. The physiological quality of the seeds was assessed using germination, accelerated aging, and electrical conductivity tests, and the speed of germination index (SGI) and mean germination time (MGT) were determined for both the germination test and accelerated aging test. For the statistical analysis, we performed regression model adjustments and calculated the Pearson correlation coefficient (p < 0.05). The germination test for H. undatus seeds can be performed at 25 °C, with the aim of reaching the highest SGI and lowest MGT values. The accelerated aging test can be conducted at 43 °C for 48 h, because combining these factors favors the expression of seed vigor, allowing seeds to achieve the maximum SGI and minimum MGT, while reducing the time of the assay. The electrical conductivity test can be performed using 25 seeds at a temperature of 30 °C and a water volume of 10 mL, since under these conditions there is less interference from external factors on the leachate content of the solution.


2019 ◽  
Vol 11 (17) ◽  
pp. 260
Author(s):  
Gabriel Pereira de Souza ◽  
Isa Anastacia Borges ◽  
Cleiton Gredson Sabin Benett ◽  
Érica Fernandes Leão-Araújo ◽  
Carmen Rosa da Silva Curvêlo ◽  
...  

Invasive plants may present allelopathic substances that interfere with the germination and initial development of seedlings of various species. The objective of this study is to evaluate the physiological quality of cabbage and tomato seeds in the presence of different concentrations of purple nutsedge extract. The seeds were left to germinate in different substrates. Individual experiments were performed for both species. Five concentrations (0, 25, 50, 75 and 100%) of aqueous extract obtained from tubers of Cyperus rotundus were used. The seeds of each species were placed to germinate in three types of substrates (sand, commercial, and paper). Germination, normal seedlings, abnormal seedlings, non-germinated seeds, germination speed index, and accelerated aging were evaluated. A completely randomized experiment with a 3 &times; 5 factorial design (three substrates and five concentrations of purple nutsedge extract) was conducted with four replications. For the substrates, the means were compared by Tukey test at 5% probability. Polynomial regression analyses were carried out for concentrations of purple nutsedge extract. Cyperus rotundus exerts allelopathic effects on the germination of tomato and cabbage seeds. As the concentration of the tuber extract increases, the inhibitory effect increases, thus reducing germination and seed vigor in the different substrates. The commercial substrate for tomato and the paper substrate for cabbage may minimize the allelopathic effects of Cyperus rotundus extract during germination of seeds.


2018 ◽  
Vol 40 (1) ◽  
pp. 52-59
Author(s):  
Solange Carvalho Barrios Roveri Jose ◽  
Antonieta Nassif Salomão ◽  
Luis Alberto Martins Palhares de Melo ◽  
Izulmé Rita Imaculada Santos ◽  
Bruno Galvêas Laviola

Abstract: Jatropha seeds are classified as orthodox. However, since it is an oil seed species, adequate storage conditions are required to ensure their longevity. The objective of this work was to evaluate the physiological quality of jatropha seeds stored in different environments and packaging, for periods of 3, 9 and 15 months. Three types of seed packaging bags (high density plastic bag, aluminized envelope and multiwall paper bag) were used, and the storage environments were cold and dry chamber (20 °C and 15% RH, constant), refrigerator (7 ± 3 °C, 48 ± 8% RH) and laboratory conditions (25 ± 3 °C, 51 ± 7% RH). The initial moisture content and seed germination were 7.1% and 89%, respectively. During storage, the physiological quality (germination and vigor) and moisture content of the seeds were evaluated. Seed water content ranged from 3.3 to 7.7%, depending on the permeability of the packaging and the storage environment. The highest longevity (15 months) without loss of viability was observed for jatropha seeds with initial moisture of 7.1%, packed in semipermeable plastic. Seed vigor was maintained, regardless of the environment and the type of packaging used, for up to nine months of storage.


2019 ◽  
Vol 41 (2) ◽  
pp. 187-195 ◽  
Author(s):  
André Dantas de Medeiros ◽  
Laércio Junio da Silva ◽  
Nayara Pereira Capobiango ◽  
Camila Andrade Fialho ◽  
Denise Cunha Fernandes dos Santos Dias

Abstract: Automated analysis of seed vigor stands out by allowing greater accuracy, standardization, objectivity, and speed in evaluation of the physiological potential of seed lots. The objective of this study was to evaluate the efficiency of the Vigor-S® system in assessing the physiological quality of common bean seeds compared to the information provided by the traditional vigor tests recommended for this species. Four genotypes of common bean were used, each one represented by four seed lots. Characterization of the physiological potential of the lots was carried out by the following tests: germination, first count of germination, seedling emergence, accelerated aging, and electrical conductivity. The results of these tests were compared with the data obtained from the image analysis technique, specifically the Vigor-S® system, which was used to evaluate seedling growth at two, three, and four days after the beginning of the germination test. Shoot length, primary root length, and seedling length were measured, as well as the growth index, uniformity index, and vigor index were calculated. Computerized analysis of seedling images using the Vigor-S® software is a reliable alternative for evaluation the physiological potential of bean seeds, and it produces information similar to evaluations traditionally used for that purpose.


2017 ◽  
Vol 39 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Cristian Rafael Brzezinski ◽  
Julia Abati ◽  
Fernando Augusto Henning ◽  
Ademir Assis Henning ◽  
José de Barros França Neto ◽  
...  

Abstract: The aim of this work was to evaluate the effect of different spray volumes, via industrial treatment, on the physiological quality of soybean seeds with different levels of vigor. The experimental design was completely randomized in a 2x5 factor scheme, with four replications. Factors consisted in two levels of seed vigor (high and low) and five spray volumes (0, 600, 1200, 1800 and 2400 mL. 100 kg-1). Products used to obtain the volumes were: fungicide (carbendazin + thiram); insecticide (imidacloprid + thiodicarb); nematicide (abamectin); micronutrients (cobalt, molybdenum and zinc); polymer (peridiam); biostimulants (kinetin + gibberellic acid) and inoculum (Bradyrhizobium japonicum). The used cultivars were BRS 360 RR and BRS 1010 IPRO. The physiological seed quality was determined by the following evaluations: germination, first count of the germination test, seedling emergence in sand, emergency speed index, total length of shoot and root of the seedlings. In the different spray volumes, high vigor soybean seeds have higher physiological quality than low vigor seeds. The increased spray volumes in seed treatments reduce the physiological quality of low vigor soybean seeds.


2017 ◽  
Vol 47 (3) ◽  
pp. 312-320 ◽  
Author(s):  
Alan Mario Zuffo ◽  
Joacir Mario Zuffo Júnior ◽  
Everton Vinicius Zambiazzi ◽  
Fábio Steiner

ABSTRACT Delayed harvesting may affect the physiological quality of soybean seeds, due to adverse conditions in the field. This study aimed to evaluate the physiological and sanitary quality of soybean seeds (BRS 820 RR® cultivar) harvested at eight periods (0; 5; 10; 15; 20; 25; 30; and 35 days after the R8 phenological stage - full maturity) and stored for two periods (0 and 8 months). The following evaluations were carried out: moisture content, germination and emergence rate, emergence speed index, total plant dry mass, accelerated aging, electrical conductivity, mechanical damage, vigor and viability (tetrazolium) and sanitary quality of the seeds. The delayed harvesting of soybean seeds from 10 days after R8 impairs seed vigor and germination, in addition to increase the incidence of pathogens. Regardless of the harvesting period, the soybean seeds stored for eight months showed a reduction in their physiological quality, with an increase in the incidence of Phomopsis spp.


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