scholarly journals Corynespora cassiicola in soybean seeds – incidence and transmission

2020 ◽  
Vol 36 ◽  
Author(s):  
Augusto César Pereira Goulart ◽  
Carlos Mitinori Utiamada
Keyword(s):  
Seed Germination ◽  
Transmission Rate ◽  
Seedling Emergence ◽  
Point Of View ◽  
Soybean Seeds ◽  
Corynespora Cassiicola ◽  
Initial Development ◽  
Soybean Seedlings ◽  
Target Spot ◽  
Seed Pathology

The fungus Corynespora cassiicola, causal agent of target spot in soybeans, has been considered, from the seed pathology point of view, a seed-borne pathogen of limited importance. Therefore, little importance has been given to the role of the seeds in the transmission of this pathogen. The objectives of this study were to determine the incidence of C. cassiicola in soybean seeds and evaluate the effects of this seed-borne pathogen, inoculated in the seeds, in relation to physiological and epidemiological parameters. The experiments were carried out at TAGRO and Embrapa Western Agriculture under lab (blotter test and seed germination test) and greenhouse conditions (growing on test). The fungus C. cassiicola was detected in 11.3% of the 639 seed samples analyzed, with an average incidence of 0.91% and maximum of 8.5%. The transmission of C. cassiicola from the seeds to above-ground parts of soybean seedlings was demonstrated, by pathogen establishment on the cotyledon, showing circular lesions with concentric rings, reddish-brown in the center and surrounded by a yellowish green halo, as a typical symptoms of target spot. Reddish-brown lesions on the roots and stem of the seedlings were also observed. Considering a sample seed with 66.0% of C. cassiicola incidence, the symptomatic transmission based on cotyledon symptoms was 42.2%, corresponding to a transmission rate of 2.4:1. This is the first report, in a quantified way, about the transmission of C. cassiicola from the seeds to above-ground parts of soybean seedlings. When compared to non-inoculated seeds, seed germination, seedling emergence and seedling initial development were influenced by the presence of the pathogen in the seeds, with the lowest values being observed when the seeds were inoculated.

scholarly journals Seed priming with sodium nitroprusside attenuates the effects of water deficit on soybean seedlings

2019 ◽  
Vol 10 (1) ◽  
pp. 176-184
Author(s):  
Marina Alves Gavassi ◽  
Lucas Aparecido Gaion ◽  
Carolina Cristina Monteiro ◽  
Joel Cabral Santos ◽  
Rogério Falleiros Carvalho
Keyword(s):  
Nitric Oxide ◽  
Sodium Nitroprusside ◽  
Water Deficit ◽  
Field Capacity ◽  
Seed Priming ◽  
Carotenoid Biosynthesis ◽  
Soybean Seeds ◽  
Initial Development ◽  
Soybean Seedlings ◽  
Fundamental Part

Considering that water deficit is one of the main environmental factors responsible for low soybean yield and that nitric oxide (NO) has been shown to be a fundamental part of plant defense signaling during stress, the aim of the present study was to evaluate the effect of seed priming with nitric oxide on the induction of water deficit tolerance during the initial development of soybean. Thus, seeds were treated with 0 (water only), 50, 100 or 250 μmol.L-1 sodium nitroprusside for 6 hours. Additionally, untreated seeds were used. After drying, the seeds were placed in containers filled with a commercial substrate mixture and vermiculite and irrigated to 100% and 50% field capacity. Biometric and biochemical evaluations (pigment and proline contents) were performed after 14 days. It was concluded that pretreatment of soybean seeds with 50 to 250 μmol.L-1 SNP attenuated the effects of water deficit on stem growth, leaf area, and shoot dry matter and induced carotenoid biosynthesis. The accumulation of proline in the leaves was pronounced in the treatments with 100 and 250 μmol.L-1 SNP, while 100 μmol.L-1 SNP induced proline accumulation in the roots.

scholarly journals Effect of the storage of soybean seeds treated with agrochemicals on the physiological quality and on the seedlings morphology

2020 ◽  
Vol 6 ◽  
pp. 1-8
Author(s):  
João Pedro Garcia Nogueira ◽  
Danúbia Aparecida Costa Nobre ◽  
Guilherme Ferreira Alves ◽  
Éder Matsuo ◽  
Willian Rodrigues Macedo
Keyword(s):  
Seed Treatment ◽  
Storage Time ◽  
Soybean Seeds ◽  
Initial Development ◽  
Soybean Seedlings ◽  
Anthranilic Diamide ◽  
Seedling Length ◽  
Physiological Quality ◽  
The One

Seed treatment is the most efficient technique for controlling pests and pathogens that can influence the initial development of the crop. However, storing treated seeds may damage the physiological quality. Thus, the objective of this study was to evaluate the influence of storage on the physiological quality of treated soybean seeds and on the morphology of soybean seedlings. The treatments were carried out with Fludioxonil, Imidacloprid and Anthranilic Diamide, in the dosage of 200, 150 and 100 mL of the commercial product 100 kg of seeds, respectively, from the cultivar BRSMG752S. The experimental designs used were randomized blocks (greenhouse) and completely randomized (laboratory), in a simple factorial 4x4scheme, with 4 sowing times (30, 20, 10 and 0 days after treatments) and 4 treatments (3 products and untreated seeds) with 4 repetitions. The treatment of soybean seeds with Anthranilic Diamide submitted to different storage periods was the one with the closest physiological quality to the treatment without application of agrochemicals. The soybean seeds treated with Imidacloprid showed a reduction in physiological quality with the storage time, reduction (in general) in the root length and presented a lower seedling length at 20 days of storage.

scholarly journals Physiological potential of soybean seeds over storage after industrial treatment

2018 ◽  
Vol 40 (3) ◽  
pp. 272-280 ◽  
Author(s):  
Lucas Caiubi Pereira ◽  
Mayara Mariana Garcia ◽  
Alessandro Lucca Braccini ◽  
Gláucia Cristina Ferri ◽  
Andreia Kazumi Suzukawa ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Emergence ◽  
Accelerated Aging ◽  
Storage Period ◽  
Soybean Seeds ◽  
Fertilizer Use ◽  
Thiophanate Methyl ◽  
Pesticide Mixtures ◽  
Randomized Design ◽  
Completely Randomized Design

Abstract: The aim of this study was to evaluate the effect of industrial seed treatments on the physiological potential of soybean seeds over storage. Four mixtures of agrochemical products in association with two fertilizers were tested. The agrochemical product mixtures were carbendazim/thiram + imidacloprid/thiodicarb; pyraclostrobin, thiophanate-methyl, and fipronil; thiophanate-methyl/fluazinam + bifenthrin/imidacloprid; and metalaxyl-m/fludioxonil + thiamethoxam. The two fertilizers were 7% N, 16% P2O5, 0.6% Co, and 2.5% Mo; and 1% Co, 10% Mo, and 7% P2 O5. The experiment was carried out in a completely randomized design in a split-plot arrangement in time, with four replications. The treatments were allocated in the plots, while the storage periods (0, 30, 60, 90, and 120 days) constituted the split-plots. The following tests were carried out in each period: first count of germination, germination, accelerated aging, emergence speed index in sand substrate, and final seedling emergence in sand substrate. Seed germination and vigor declined over the storage period, especially after industrial treatment. Pesticide mixtures of a carbendazim/thiram fungicide base and an imidacloprid/thiodicarb insecticide base most impaired seed physiological potential throughout storage, regardless of fertilizer use in the industrial treatment.

scholarly journals Conventional PCR for detection of Corynespora cassiicola in soybean seeds

2016 ◽  
Vol 38 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Marcella Viana de Sousa ◽  
Carolina da Silva Siqueira ◽  
José da Cruz Machado
Keyword(s):  
Pure Culture ◽  
Early Stage ◽  
Soybean Seeds ◽  
Inoculum Potential ◽  
Corynespora Cassiicola ◽  
Severe Damage ◽  
Conventional Pcr ◽  
Seed Testing ◽  
Target Spot ◽  
Specificity And Sensitivity

Abstract The fungus Corynespora cassiicola, causal agent of target spot in soybeans, can be transmitted by soybean seeds and as of that point cause severe damage. This disease may be diagnosed at an early stage by seed testing, but knowledge in this area is insufficient. Because of that and increased attack by the disease in soybean areas in Brazil, further studies are required. The aim of this study was to evaluate the use of conventional PCR in detecting C. cassiicola in soybean seeds. The GA4-F/GA4-R primers described in the literature were tested for their specificity and sensitivity for detection of C. cassiicola in pure culture and in soybean seeds. Uninoculated and inoculated seed samples were used with different incidence levels - 100%, 10%, 1%, 0.5%, 0.25%, and 0% of preestablished inoculum potentials, P0, P1, P2, and P3. Detection of C. cassiicola in P1 inoculum potential was observed in samples with incidence levels of 10% to 100%. In the P3 potential, detection of the pathogen was successful in samples at the low level of 0.25%.

scholarly journals Incidence of storage fungi and hydropriming on soybean seeds

2013 ◽  
Vol 35 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Denis Santiago da Costa ◽  
Nathalie Bonassa ◽  
Ana Dionisia da Luz Coelho Novembre
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Seedling Emergence ◽  
Mechanical Damage ◽  
Soybean Seed ◽  
Accelerated Aging ◽  
Soybean Seeds ◽  
Storage Fungi ◽  
Randomized Experimental Design ◽  
Low Incidence

Priming is a technique applicable to seeds of various plant species; however, for soybean seed there is little available information correlating such technique to the storage fungi. The objective of this study was to assess hydropriming on soybeans seeds and correlate this technique to occurrence of such fungi. For this, soon after acquisition the soybean seeds, cv. M-SOY 7908 RR, were characterized by: moisture content, mechanical damage, viability (seed germination and seedling emergence) and seed health. A completely randomized experimental design was used with treatments arranged into a factorial scheme 2 × 2 [2 levels of incidence of storage fungi (low and high) × 2 hydropriming (with and without) ]. After application of treatments, the seeds were analyzed by: moisture content, viability (seed germination and seedling emergence) and vigor (first count and accelerated aging). The hydropriming is beneficial to improve the quality of soybean seeds with low incidence of storage fungi, with increments on speed germination (first count) and seed germination after accelerated aging test. The high incidence of microorganisms can reduce the hydropriming benefits.

PATHOGENICITY OF CORYNESPORA CASSIICOLA ON SOYBEAN

1965 ◽  
Vol 43 (11) ◽  
pp. 1461-1469 ◽  
Author(s):  
W. L. Seaman ◽  
R. A. Shoemaker ◽  
E. A. Peterson
Keyword(s):  
Secondary Infection ◽  
Sesamum Indicum ◽  
Field Bean ◽  
Infested Soil ◽  
Corynespora Cassiicola ◽  
Vigna Sinensis ◽  
Soybean Seedlings ◽  
Target Spot ◽  
Agar Media ◽  
Mature Field

Corynespora cassiicola was pathogenic on the roots and hypocotyls of soybean seedlings grown in infested soil at Ottawa. Extensive superficial necrotic lesions developed on seedlings from inoculated seeds planted in the field in mid-May, but few symptoms appeared on seedlings planted in late May and in June. Infected plants were initially stunted but recovered with little effect on size or yield. In controlled temperature studies, severe root and hypocotyl rot were produced on inoculated seedlings at 15–20 °C. Symptoms were less severe at temperatures alternating from 15 or 20 °C to 25–35 °C and were negligible on seedlings kept constantly at 25–35 °C. Optimum growth of the fungus on agar media occurred at 20 °C. At 5 °C and 35 °C conidia germinated, but no appreciable mycelial growth occurred; at 30 °C growth was greatly restricted. Typical symptoms of target spot were produced on the inoculated foliage of soybeans in the greenhouse and in the field, but secondary infection was not observed in the field. Foliage infection occurred on cowpea (Vigna sinensis), sesame (Sesamum indicum), and Hartsville cotton (Gossypium hirsutum) in the greenhouse. C. cassiicola was isolated from overwintered soybean root debris, from the roots of mature field bean (Phaseolus vulgaris), and from the roots of soybean seedlings grown in soil not previously cropped with soybeans.

scholarly journals The Effect of Mineral Supplementation on the Physiological Quality, Enzymes Activity and the Soybean Seedlings Development

2020 ◽  
Vol 8 (4) ◽  
pp. 678
Author(s):  
Gerusa Massuquini Conceição ◽  
Thomas Newton Martin ◽  
Luciane Almeri Tabaldi ◽  
Glauber Monçon Fipke ◽  
Charleston Dos Santos Lima
Keyword(s):  
Seed Treatment ◽  
Nutrient Content ◽  
Guaiacol Peroxidase ◽  
Soybean Seeds ◽  
Nutritional Content ◽  
Initial Development ◽  
Soybean Seedlings ◽  
Mineral Supplementation ◽  
Physiological Quality

The quality of soybean seeds is influenced by the amount of nutrients that are available for the germination and initial development of the seedlings. Thus, the aim of this research was to evaluate the influence of the nutritional content of the seeds and mineral supplementation via seed treatment on physiological quality, enzymatic activity and initial development of soybean seedlings. We assessed soybean seeds from two lots with low and high nutritional content, submitted or not to mineral supplementation via seed treatment. The physiological quality of seeds was assessed by the germination test and first germination count. The initial development of seedlings was evaluated by the tests of length and root system volume, shoot length, and cotyledons, roots and shoot dry matter. It was also determined the activity of α-amylase in cotyledons, acid phosphatase (APase) and guaiacol peroxidase (POD) in the roots and shoot. Mineral supplementation via seed treatment positively influenced the physiological quality and development of seedlings, and the activity of α-amylase in the cotyledons, POD and APase enzymes in the shoot from the low nutrient lot. Low nutrient seeds have characteristics of soybean seedling production similar to those of high nutrient content by using mineral supplementation via seeds.

scholarly journals Physiological potential of soybean industrially treated with different spray volumes and dry powder

2020 ◽  
pp. 836-841
Author(s):  
Julia Abati ◽  
Cristian Rafael Brzezinski ◽  
Claudemir Zucareli ◽  
Flávia Werner ◽  
Ademir Assis Henning ◽  
...  
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Seed Treatment ◽  
New Technologies ◽  
Seedling Emergence ◽  
Soybean Seeds ◽  
Dry Powder ◽  
Soybean Seedlings ◽  
Randomized Experimental Design ◽  
Physiological Quality

The industrial treatment of seeds has favored the development of new technologies such as the use of dry powder. It has made application of spray volumes higher than those used in the conventional treatment. Therefore, this study aimed to assess the effect of industrial treatments at different spray volumes with and without application of dry powder on physiological quality of soybean seeds. A completely randomized experimental design was performed with four replications in a 5 x 2 factorial arrangement for cultivars BRS 359 RR and BRS 284. The factors were five spray volumes (0, 600, 1200, 1800 and 2400 mL. 100 kg-1) with and without the application of dry powder. The products used to obtain the volumes were fungicides (carbendazim + thiram); insecticides (imidacloprid + thiodicarb); nematicide (abamectin); micronutrients (cobalt, molybdenum and zinc); polymer (peridiam); biostimulant (kinetin + gibberellic acid + 4-indol-3-ylbutyric acid) and inoculant (Bradyrhizobium japonicum). The physiological quality of the seeds was determined by the following assessments: germination, first count of germination test, seedling emergence in sand, emergence speed index, and total length of the seedling shoot and root. The results showed that increased spray volume associated with the application of dry powder in seed treatment reduced the physiological quality of soybean seeds, and spray volumes up to 1200 mL 100 kg-1 in seed treatment without the application of dry powder do not impact the emergence and establishment of soybean seedlings.

scholarly journals Effects of Stenocarpella maydis in seeds and in the initial development of corn

2014 ◽  
Vol 36 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Carolina da Silva Siqueira ◽  
Ellen Noly Barrocas ◽  
José da Cruz Machado ◽  
Ursula Abreu da Silva ◽  
Iara Eleutéria Dias
Keyword(s):  
Seed Germination ◽  
Early Development ◽  
Seed Quality ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Seed Vigor ◽  
Negative Effects ◽  
Initial Development ◽  
Corn Seed ◽  
Stenocarpella Maydis

The association of the fungus Stenocarpella maydis with corn seed may cause a reduction of seed germination and vigor of the emerged seedlings. This work was carried out in order to evaluate the effects of S. maydis on corn seed quality as well as on its early development. To evaluate such effects, seeds of cultivars RB9308YG (C1) and RB9108 (C2) were inoculated by the osmotic conditioner technique with two S. maydis isolates for 24(P1), 48(P2), 72(P3) and 96 hours (P4). Plants were grown in a room chamber at 20 °C and 25 °C and daily assessed until 28 days after emergence. Seed germination, incidence of S maydis, electrical conductivity, speed of emergence index (SEI), initial and final seedling population and dry weight of emerged plants, were assessed. The longer the exposition times of the seeds to the fungal colony, the more severe negative effects of the pathogens on seed vigor were observed. S. maydis caused reduced seed vigor in the speed of seedling emergence in the final stand and early development of corn seedlings.

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