scholarly journals Evaluation of inoculum potential of pathogens in seeds: relation to physiological quality and DNA quantification by qPCR

2017 ◽  
Vol 39 (3) ◽  
pp. 224-233 ◽  
Author(s):  
Marina de Resende Faria Guimarães ◽  
Carolina da Silva Siqueira ◽  
José da Cruz Machado ◽  
Sueny Kelly Santos de França ◽  
Gabriel Castanheira Guimarães
Keyword(s):  
Germination Percentage ◽  
Seed Vigor ◽  
Soybean Seeds ◽  
Inoculum Potential ◽  
Water Restriction ◽  
Maize Seeds ◽  
Seed Health ◽  
Physiological Quality ◽  
Cotton Seeds ◽  
Stenocarpella Maydis

Abstract: Given what is already known in regard to seed health and the availability of molecular methods for detection of the pathogens Stenocarpella maydis and Stenocarpella macrospora in maize seeds, Colletotrichum gossypii var. cephalosporioides in cotton seeds, and Corynespora cassiicola in soybean seeds, the aim of this study was to evaluate seed vigor according to different inoculum potentials. The fungus isolates were inoculated on seeds by the technique of water restriction, through which different inoculum potentials are obtained, corresponding to times of seed exposure of 0, 24, 48, and 96 hours for maize and cotton seeds, and 0, 36, 108, and 144 hours for soybean seeds. The seeds were subjected to germination, electrical conductivity, health, and qPCR tests. Results of the blotter test showed that in most pathosystems, there was a higher incidence of the fungi with an increase in inoculum potential. A decrease in germination percentage was observed in all species as inoculum potential increased, as well as further degradation of seed membranes. The qPCR test confirmed that the most damaged seeds in the tests had higher presence of the pathogens.

scholarly journals Temperatures and substrates for germination and vigor of Erythroxylum pauferrense Plowman seeds

2019 ◽  
Vol 41 ◽  
pp. e46030
Author(s):  
João Everthon da Silva Ribeiro ◽  
Arliston Pereira Leite ◽  
Jackson Silva Nóbrega ◽  
Edna Ursulino Alves ◽  
Riselane de Lucena Alcântara Bruno ◽  
...  
Keyword(s):  
Dry Mass ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Randomized Design ◽  
Temperature Regimes ◽  
Seedling Length ◽  
Physiological Quality ◽  
Mean Germination Time ◽  
Completely Randomized Design ◽  
Understory Plant

Erythroxylum pauferrense is an endemic understory plant species of the Northeast Region of Brazil. The species is of great importance to the region and so ecophysiological studies are needed for its preservation. The objective of the present study was to determine the best substrates and temperatures for testing germination and seed vigor of E. pauferrense. An experiment was performed comprising a completely randomized design in a 5 x 4 factorial scheme, with five temperature regimes (20, 25, 30, 35°C constant and 20-30°C alternating) and four types of substrates (paper, vermiculite, sand and commercial substrate). The following characteristics were evaluated: germination percentage, first germination count, germination speed index, mean germination time, seedling length and dry mass (root and shoot). Paper and vermiculite substrates combined with constant temperatures of 20, 25, 30 and alternated between 20-30°C, provide greater seed germination and vigor while 35°C reduces seed physiological quality.

scholarly journals Specificity and sensibility of primer pair in the detection of Colletotrichum gossypii var. cephalosporioides in cotton seeds by PCR technique

2020 ◽  
Vol 42 ◽  
Author(s):  
Mirella Figueiró de Almeida ◽  
Sarah da Silva Costa ◽  
Iara Eleutéria Dias ◽  
Carolina da Silva Siqueira ◽  
José da Cruz Machado
Keyword(s):  
Cotton Seed ◽  
Water Restriction ◽  
Seed Certification ◽  
Certification Programs ◽  
Seed Health ◽  
Target Dna ◽  
Cotton Seeds ◽  
Primer Sets ◽  
Specific Fragment ◽  
Cotton Plantations

Abstract: Cotton Ramulosis (Gossypium hirsutum) is an important disease affecting cotton plantations in Brazil, and its causal agent, Colletotrichum gossypiivar.cephalosporioides(Cgc), according to the Brazilian phytosanitary authority, was considered a regulated non quarantine pest. It makes this microorganism subject to standardization in seed certification programs. The current seed health testing for detecting that pathogen in seed samples does not provide reliable results for routine analysis. On this paper, attempts were made to design specific primers for detection of Cgc associated with cotton seed. Two primer sets were selected based on the analysis of a multiple alignment of gene’s sequence encoding the glyceraldehyde 3-phosphate dehydrogenase from Cgc, C. gossypii and reference strains of the C. gloeosporioides species complex. The conserved sites unique to Cgc strains were used to design specific fragment of 140 bp. The primer specificity was confirmed by using other fungi. The primers produced a detectable band of target DNA of Cgc in all inoculum potentials of the pathogen artificially inoculated by the water restriction technique. The developed primer pair represents, therefore, a reliable and rapid mean to diagnose the Ramulosis agent in cotton seed.

scholarly journals Correlation between vigor by accelerated aging at pre-sowing and soybean seedling emergence in the field

2021 ◽  
Vol 42 (2) ◽  
pp. 455-470
Author(s):  
Vanderléia Mathias ◽  
◽  
Cileide Maria Medeiros Coelho ◽  
Keyword(s):  
Exposure Time ◽  
Seedling Emergence ◽  
Soybean Seed ◽  
Accelerated Aging ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Growing Seasons ◽  
Accelerated Aging Test ◽  
Physiological Quality ◽  
Field Emergence

Although the accelerated aging test is widely used to determine seed vigor, there are methodological variations in seed exposure time at 41 °C. Therefore, the objective was to indicate the most appropriate seed exposure time to segregate lots that also exhibits a correlation with seedling emergence in the field, and establish vigor levels using the aforementioned test. Soybean seed samples were collected at pre-sowing, representing 100 lots in the 2016/2017 growing season and 125 lots in the 2017/2018 season from different warehouses in 4 regions of Santa Catarina state (SC). Physiological quality was evaluated by germination, accelerated aging (24 and 48 h at 41 °C) and field emergence tests. The results were submitted to descriptive statistical analysis and Pearson’s correlation analysis (p < 0.05). The rank sum index, associated with the Scott-Knott clustering method, was used to classify physiological quality. The average germination percentage was 90 and 91% in the 2016/2017 and 2017/2018 growing seasons, respectively. Vigor obtained an average of 86 (2016/2017) and 85% (2017/2018), when seeds were submitted to accelerated aging for 48 h, and 89% (both seasons) for 24 h. In regard to field emergence, the average was 85 and 80% in the 2016/2017 and 2017/2018 growing seasons, respectively. Considering the 225 lots, the greatest correlation with field emergence was observed in vigor - 48 h (r = 0.71 p < 0.05). Rank sum classification made it possible to establish vigor-based categories, whereby batches with over 85% vigor by 48-h accelerated aging were classified as high vigor, 70 to 84% medium vigor, and under 70% low vigor.

scholarly journals Spray volumes in the industrial treatment on the physiological quality of soybean seeds with different levels of vigor

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 ◽  
...  
Keyword(s):  
Experimental Design ◽  
Bradyrhizobium Japonicum ◽  
Seed Quality ◽  
Seedling Emergence ◽  
Seed Vigor ◽  
Soybean Seeds ◽  
Germination Test ◽  
Physiological Quality ◽  
Different Levels

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.

scholarly journals Physiological and sanitary quality of soybean seeds harvested at different periods and submitted to storage1

2017 ◽  
Vol 47 (3) ◽  
pp. 312-320 ◽  
Author(s):  
Alan Mario Zuffo ◽  
Joacir Mario Zuffo Júnior ◽  
Everton Vinicius Zambiazzi ◽  
Fábio Steiner
Keyword(s):  
Mechanical Damage ◽  
Accelerated Aging ◽  
Dry Mass ◽  
Seed Vigor ◽  
Soybean Seeds ◽  
Adverse Conditions ◽  
Physiological Quality ◽  
Total Plant ◽  
Plant Dry Mass

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.

scholarly journals Physiological quality of bean seeds after application of desiccant herbicides

2019 ◽  
Vol 49 (9) ◽  
Author(s):  
Cecília Brustolini Rosado ◽  
Gustavo Antônio Mendes Pereira ◽  
Nayara Pereira Capobiango ◽  
Renata Pereira Lopes Moreira ◽  
Francisco Cláudio Lopes Freitas ◽  
...  
Keyword(s):  
Block Design ◽  
Primary Root ◽  
Accelerated Aging ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Phenological Stages ◽  
Randomized Complete Block Design ◽  
Physiological Quality ◽  
Bean Crop

ABSTRACT: The application of desiccant herbicides in the bean crop is fundamental in the production of quality seeds, since it anticipates the harvesting season, which makes it possible to obtain seeds in the period of physiological maturation, when they are reported with maximum accumulation of dry matter, high vigor levels and germination percentage. However, there is little information about the ideal application time of these products to obtain beans of high physiological quality. Therefore, the objective of this study was to evaluate the physiological quality of bean seeds after application of desiccant herbicides at different times in preharvest. The experimental design was a randomized complete block design in a 2x3+1 factorial scheme, with four replications. Desiccant herbicides paraquat (400g ha-1) and paraquat + diuron (200 + 400g ha-1) were applied in three phenological stages (R8, R8/R9 and R9), plus one control (without herbicide application). Yield (Kg ha-1), mass of one thousand seeds (g), germination (%) and seed vigor were evaluated through tests of accelerated aging, electrical conductivity and primary root length. Application of paraquat molecule at the R8 stage and the paraquat + diuron mixture at the R8/R9 stage reduced the viability and vigor of the bean seeds, and compromised yield. Applications of the paraquat herbicide at the R8/R9 and R9 stages or of the mixture (paraquat + diuron) at the R9 stage preserved the physiological quality of the seeds without;however, affecting yield.

scholarly journals Phytotoxicity in soybean seeds treated with phytosanitary products at different application times

2020 ◽  
Vol 42 ◽  
Author(s):  
Everson Reis Carvalho ◽  
Debora Kelli Rocha ◽  
Dayliane Bernardes de Andrade ◽  
Raquel Maria de Oliveira Pires ◽  
Amanda Carvalho Penido ◽  
...  
Keyword(s):  
Seed Treatment ◽  
Seed Quality ◽  
Soybean Seed ◽  
Field Performance ◽  
Soybean Seeds ◽  
Water Restriction ◽  
Hypocotyl Length ◽  
Initial Development ◽  
Physiological Quality ◽  
Phytosanitary Products

Abstract: Due to increased use of treated seeds, studies are necessary in relation to the effects of the treatments and their possible consequences on seed quality. The aim of this study was to evaluate phytotoxicity according to when phytosanitary products are applied on soybean seeds and their effect on seed physiological quality and field performance. A completely randomized experimental design was used in a 9 × 2 factorial arrangement involving 9 seed treatments (fungicides and insecticides) and two application times (60 days before sowing and at the time of sowing in the field). Moisture content was determined and tests were performed to ascertain physiological quality (germination and germination under water restriction). Root and hypocotyl length, seedling length, and vigor and uniformity indices were evaluated with the assistance of Vigor-S®. In the field, the following determinations were made: plant height at 30 and 60 days after emergence, first pod height, number of pods per plant, number of seeds per pod, and yield. Early seed treatment in the soybean crop can affect initial development of the plants, but it does not affect yield. The phytotoxicity caused by the soybean seed treatment was observed in the root length characteristic.

scholarly journals Physiological quality of Gossypium hirsutum L. seeds after the thermal delinting process

2018 ◽  
Vol 9 (3) ◽  
pp. 465-474 ◽  
Author(s):  
Pablo Radamés Cabral de França ◽  
Francisco De Assis Cardoso Almeida ◽  
Odilon Reny Ribeiro Ferreira da Silva ◽  
Jeane Ferreira Jerônimo
Keyword(s):  
Gossypium Hirsutum ◽  
Dry Weight ◽  
Dry Mass ◽  
Germination Percentage ◽  
Gossypium Hirsutum L ◽  
Mean Values ◽  
Randomized Design ◽  
Physiological Quality ◽  
Cotton Seeds

The removal of lint from cotton seeds is mainly carried out through chemical delinting, but it is an expensive procedure and requires high technology. The objective was to evaluate the physiological quality of Gossypium hirsutum L. seeds delinted by flaming using a thermal delinter prototype. Cotton seeds BRS 286 were flamed in nine settings intensities and compared to chemical delinting and seeds with lint. We analyzed the water content, germination, first count, germination speed index (GSI), length and dry mass of roots and shoots. Using a completely randomized design and the means were compared by Scott-Knott test at 5% probability. In evaluating, the germination percentage did not differ between treatments with chemical and thermal low intensity delinting compared to the control. In vigor tests were observed higher mean values of the chemical treatment to the other treatments, except in GSI test and root dry weight when subjected to thermal delinting of low and medium intensity. The delinting made through the prototype enables efficient results, as well as the chemical delinting with sulfuric acid, without affecting germination and vigor when flamed with low and middle intensity, regardless of the number of active burners.

scholarly journals Combined Effects of Biological and Chemical Treatment on Rice Seed Physiological and Sanitary Quality

2019 ◽  
Vol 11 (15) ◽  
pp. 106
Author(s):  
Alana Emanoele Pereira ◽  
Weliton Lucas da Silva Benites ◽  
Luana de Carvalho Catelan ◽  
Ana Paula Silva ◽  
Nadia Graciele Krohn
Keyword(s):  
Seed Quality ◽  
Dry Weight ◽  
Seed Vigor ◽  
Rice Seed ◽  
Water Control ◽  
Randomized Design ◽  
Seed Health ◽  
Physiological Quality ◽  
Rice Seeds

This study aimed to evaluate the efficiency of integrated biological and chemical control of pathogens in rice seeds and their effects on seed quality. The experiment was conducted in a 2 &times; 5 factorial completely randomized design. Fungicide-treated (carboxin/thiram) and untreated rice seeds were inoculated with distilled water (control), Azospirillum brasilense, Bacillus subtilis, Pseudomonas fluorescens, or Trichoderma harzianum. Seed vigor and viability, shoot and root length, and seedling dry weight were determined. The blotter test was carried out to assess seed health. Fungicide treatment improved seed vigor and viability and reduced the incidence of fungi. Biological treatment did not enhance the physiological quality of seeds but was able to control fungi. A. brasilense, B. subtilis, P. fluorescens, and T. harzianum controlled Phoma sorghina; B. subtilis, P. fluorescens, and T. harzianum were effective against Aspergillus flavus; P. fluorescens and T. harzianum controlled Pyricularia oryzae; and T. harzianum was effective against Gerlachia oryzae.

scholarly journals Influence of seed size and water restriction on germination of soybean seeds and on early development of seedlings

2013 ◽  
Vol 35 (3) ◽  
pp. 316-322 ◽  
Author(s):  
Welison Andrade Pereira ◽  
Sara Maria Andrade Pereira ◽  
Denise Cunha Fernandes dos Santos Dias
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Seed Size ◽  
Biological Process ◽  
Dry Weight ◽  
Soybean Seeds ◽  
Water Restriction ◽  
Soybean Seedling ◽  
Physiological Quality ◽  
Moisture Conditions

Germination is a biological process that depends on adequate water supply to embryo development. Water deficit slows this process and depending on intensity and extent of this deficit may cause seed death. Nevertheless, it has not yet been reported whether seed size influences physiological potential, or tolerance to water stress. This study aimed at assessing the effects of seed size, as well as of water stress on germination of the seeds and on early soybean seedling development. The experiment was composed by seeds of 10 soybean cultivars classified by metallic screens with three sizes of oval holes (S12, S13 and S14) and subjected to three water potentials (0, -0.1, and -0.2 MPa), with four replications. Data on genotypes were grouped as replications and arranged on a factorial 3 x 3 (size x water potential), with 40 replications. Data assessed were: first and final count of germination; length and seedling dry weight; and correlation between length/mass of radicle and hypocotyl. It was concluded that under ideal moisture conditions larger seeds have better physiological quality, producing more vigorous seedlings; but, that under water potential of -0.2 MPa smaller seeds produce larger seedlings; and that the hypocotyl is more influenced by water stress than the radicle.

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