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The objective of this work was to verify the effect of electromagnetic waves on the sanitary and physiological quality of soybean seeds. The seeds were submitted to different exposure periods (0, 20, 40, 60, 80, 100, 120, 140 and 160 seconds), under electromagnetic waves with power of 900 W and frequency of 2.45 GHz, using the micro-ondas and the fungicide dicarboximide (250 g. 100 kg-1 of seeds), as an additional treatment. For the sanity test, 200 seeds were used per treatment, distributed in ten seeds per Petri dish. In the physiological test, 200 seeds per treatment were also used, distributed in 50 seeds per Germitest paper. The experimental design used was completely randomized, with ten treatments and four replications of 50 seeds each. The fungi, Aspergillus niger, Aspergillus flavus, Penicillium sp. and Fusarium sp. All periods of exposure to electromagnetic waves were efficient in reducing fungi identified in seeds. The sanitary and physiological quality was favored when the soybean seeds were exposed for up to 60 seconds, under a power of 900 W and a frequency of 2.45 GHz. The exposure of soybean seeds in periods longer than 80 seconds, under conditions of potency and frequency studied, had a negative effect on the percentage of hard seeds. [ABSTRACT FROM AUTHOR]

Thermal treatment is frequently used to overcome dormancy in forest seeds; however, it can also be used to control seed-born pathogens. This study aimed to evaluate the efficiency of thermotherapy in controlling Fusarium sp. in angico seeds [Anadenanthera colubrina (Vell.) Brenan] collected in the state of Paraíba, Brazil, and its effect on physiological quality. Nine seed sources located in the municipalities of São João do Cariri - PB, Boa Vista - PB, and Sumé - PB were selected for this study. For the sanitary test, the treatments were composed of untreated seeds (control), chemical treatment, and thermal treatment at temperatures of 50, 60, and 70 °C immersed for 10, 20, 30, and 40 minutes. The same treatments were used in the germination test, and the percentage of germination, first count, dead seeds, seedling length, and germination speed index were evaluated. The results showed that the thermal treatments effectively reduced Fusarium sp. in the seeds. Thermotherapy did not negatively affect the physiological quality of angico seeds and led to an increase in germination percentage. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fusarium head blight (FHB) is a disease of wheat caused by the Fusarium graminearum species complex in which Fusarium meridionale is included. The seed is an inoculum source and the use of inoculated seeds for this pathosystem studies can optimize the time of experimental tests. However early germination of seed during the inoculation process can make studies on the FHB pathosystem very challenging. Therefore, this study aimed to determine the optimal water restriction condition and time of exposure for inoculation of F. meridionale in wheat seeds without reducing seed germination, to define a reliable and rapid technique for inoculating FHB using wheat seeds. Mycelial discs of F. meridionale were placed in the center of Petri dishes containing potato dextrose agar (PDA) media with different quantities of mannitol to establish water potentials of −0.4, −0.6, −0.8, −1.0 or − 1.2 MPa. A control plate with only PDA had −0.36 MPa. Mycelial growth was measured for 178 hours post inoculation (hpi). Wheat seeds were placed in contact with the mycelium at 12, 24, 36, 48 or 60 hpi. Seed germination and seed pathology were evaluated. The greatest growth of the pathogen was at water potentials between −0.8 and − 1.06 MPa. Seed germination was not affected by the water potential at 12 hpi. It was verified that at −1.0 MPa the seeds did not germinate early, and the pathogen was detected in 100% of the inoculated seeds. Thus, the use of mannitol at water potential of −1.0 MPa and seed contact with the pathogen at 12 hpi is a method that can be used for inoculation of F. meridionale in wheat seeds. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effect of Eucalyptus globulus essential oil on the health and physiological quality of seeds of Mimosa caesalpiniifolia Benth. and the transmission of Fusarium sp. associated with seeds. The seeds were immersed in four concentrations of E. globulus essential oil (0.25%; 0.50%; 0.75% and 1.0%). The seeds were also treated with Captana fungicide (240g for 100 kg of seeds) and immersed in sterile distilled water (control). After being treated, the seeds were evaluated by the health test, using the filter paper method (blotter test) and by the physiological quality through germination, first count, germination speed index and seedling length. The transmission of Fusarium sp. via seeds was also assessed, as it is considered potentially pathogenic. The identified fungi were: Cladosporium sp. (16.5%), Aspergillus sp. (15.5%), Fusarium sp. (7.5%), Penicillium sp. (4.0%), Rhizopus sp. (2.5%) and Periconia sp. (0.5%). The essential oil of E. globulus, in any concentration, reduced efficiently the incidence of fungi associated with M. caesalpiniifolia seeds and did not affect the physiological quality of the treated seeds. Fusarium sp. was transmitted via seeds and caused root rot and hypocotyl necrosis. [ABSTRACT FROM AUTHOR]

Seed health test prior to planting may prevent the introduction of pathogens in absence areas, provides data to farmers, certification programs, vegetal vigilance service, treatment of seeds and plant improvement. Current study evaluates the sanitary and physiological quality of cotton seeds from different producing areas in the state of Paraíba, Brazil. Seeds from different cotton cultivars were used, coupled to the producing municipality: Rubi (Juarez Távora; PB), Topázio (Juarez Távora; PB), Topázio (Remígio; PB), Aroeira (Remígio; PB), BRS 286 (Alagoinha; PB) and cotton seeds Mocó (Casserengue; PB, Sumé; PB, Quixaba; PB, São Mamede; PB and Remígio; PB). Fungi in seeds were detected by incubation through the blotter test. Physiological quality was evaluated by germination, first germination count, germination speed index, length of aerial part and root, dry matter of aerial part and root. Twenty-five fungus genera associated with cotton seeds were identified: Alternaria sp., Aspergillus spp., A. flavus, A. niger, Botryodiplodia sp., Botrytis sp., Cercospora sp., Chaetomium sp., Cladosporium sp., Colletotrichum sp., Curvularia sp., Fusarium sp., Helmithosporium sp., Monilia sp., Neorospora crassa, Nigrospora sp., Penicillium spp., Periconia sp., Phoma sp., Pytomices sp., Rhizoctonia sp., Rhizopus sp., Sclerotinia sp., Trichoderma sp. and Verticillium sp. Seeds of cultivar BRS 286 had the best health and physiological quality, whilst cotton seeds Mocó from Sumé and São Mamede had the highest occurrence rates of fungi and the lowest physiological quality. [ABSTRACT FROM AUTHOR]

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The chemical control of pathogens in seeds is mainly undertaken by synthetic fungicides, although there is a need for alternatives that would not contaminate the environment and humans, with special reference to biological control by antagonists such as Trichoderma spp. Current research evaluates the influence of Trichoderma spp. on the health and physiological aspects of the seeds of Astronium urundeuva (M. Allemão) Engl. Treatments were applied by direct contact of seeds with the fungus, as blanks (asepsis only); fungicide captana® (240 g 100 kg-1 seeds) and seven different isolates of Trichoderma sp. inoculated seeds by Trichoderma sp. were conditioned on Aspergillus sp. colonies maintained during 24 h in direct contact. After treatments, seeds underwent health, germination and emergence tests. The employment of Trichoderma spp. was sufficient for reduction of Aspergillus niger occurrence in seeds of A. urundeuva and increased germination of seeds and seedlings' strength. [ABSTRACT FROM AUTHOR]

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Quinoa downy mildew, caused by Peronospora variabilis , is the most devastating disease of quinoa globally. Rapid, sensitive diagnostic methods are needed to detect and quantify this pathogen in seeds and plant tissue. A hydrolysis probe-based quantitative real-time PCR (qPCR) assay including a competitive internal control was developed for P. variabilis detection. This assay could detect as low as 20 ag of DNA or approximately 25 internal transcribed spacer (ITS) copies per reaction with efficiencies ranging from 93.9 to 98.2%. No nontarget amplification was observed when tested against DNA from other downy mildew pathogens and related oomycetes. P . variabilis strains from multiple countries were detected using this assay. The assay was successfully applied to quantify the pathogen in quinoa seeds from a field trial conducted in the state of Washington. Downy mildew disease was recorded on all 14 genotypes, with the genotypes 104.88 and 106.49 recording the highest area under the disease progress curve values (mean ± SE; 3,236 ± 303 and 2,851 ± 198, respectively) and J6 and Dutchess recording the lowest (441 ± 107 and 409 ± 129, respectively). Seed washes obtained from field samples were subjected to the qPCR assay, and the pathogen was detected in all samples. The highest pathogen ITS copy number was recorded with 106.49 (194,934 ± 38,171), and the lowest was observed in Pasto (5,971 ± 1,435) and Riobamba (9,954 ± 4,243). This qPCR assay could lead to improved detection and quantification of P. variabilis as well as increased understanding of quinoa- P. variabilis interactions and epidemiology., Competing Interests: The author(s) declare no conflict of interest.

Bacterial canker of tomato caused by Clavibacter michiganensis ( Cm ) is one of the most devastating bacterial diseases affecting the tomato industry worldwide. As the result of Cm colonization of the xylem, the susceptible host shows typical symptoms of wilt, marginal leaf necrosis, stem cankers, and ultimately plant death. However, what makes Cm an even more dangerous pathogen is its ability to infect seeds and plants without causing symptoms. Unfortunately, there are no resistant cultivars or effective chemical or biological control methods available to growers against Cm . Its control relies heavily on prevention. The implementation of a rapid and accurate detection tool is imperative to monitor the presence of Cm and prevent its spread. In this study, we developed a specific and sensitive multiplex TaqMan qPCR assay to detect Cm and distinguish it from related bacterial species that affect tomato plants. Two Cm chromosomal virulence-related genes, rhu M and tom A, were used as specific targets. The plant internal control tubulin alpha-3 was included in each of the multiplexes to improve the reliability of the assay. Specificity was evaluated with 37 bacterial strains including other Clavibacter spp. and related and unrelated bacterial pathogens from different geographic locations affecting a wide variety of hosts. Results showed that the assay is able to discriminate Cm strains from other related bacteria. The assay was validated on tissue and seed samples following artificial infection, and all tested samples accurately detected the presence of Cm . The tool described here is highly specific, sensitive, and reliable for the detection of Cm and allows the quantification of Cm in seeds, roots, stems, and leaves. The diagnostic assay can also be adapted for multiple purposes such as seed certification programs, surveillance, biosafety, the effectiveness of control methods, border protection, and epidemiological studies.[Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license., Competing Interests: The author(s) declare no conflict of interest.

A survey of Diaporthe/Phomopsis Complex (DPC) species was carried out on 479 asymptomatic soybean (Glycine max (L.) Merrill) seed samples collected from commercial soybean fields in the states of Santa Catarina (20 counties) and Rio Grande do Sul (41 counties), in the 2020/21 (n=186), 2021/22 (n=138) and 2022/23 (n=155) seasons from 120 cultivars. The seeds were provided by seed producers who collected according to the sampling standard of the Ministry of Agriculture, Livestock and Food Supply. From each sample received, 200 symptomless seeds were randomly sorted out. The seeds were surface disinfected by immersion in a sodium hypochlorite solution (1%) for two minutes and placed on Potato Dextrose Agar (PDA). The plates were incubated for 7 days at 23°C with a photoperiod of 12-h. The average prevalence of 73.7% of DPC-infected seeds. Colonies were isolated by transferring mycelial tips to PDA and incubating for 14 days at 25ºC in a 12-h photoperiod. One colony (isolate MEMR0500) had morphological characteristics similar to those reported in Lopez-Cardona (2021). This isolate had a floccose, dense colony ranging from grayish beige to brown with greenish regions and black globose pycnidia (3 to 4 pycnidia/cm²). Alpha-conidia, 5.1 to 7.0 µm x 1.5 to 2.8 µm, were observed after 30 days and were hyaline, aseptate and fusiform (Figure S1). No beta-conidia were observed. Soybean plants of cultivars BMX Cromo IPRO, BMX Zeus IPRO, BRS 5804 RR, FPS 1867 IPRO and NEO 750 IPRO were tested for pathogenicity using the toothpick inoculation method (Siviero and Menten 1995). Non-colonized toothpicks served as a negative control. Plants were incubated for four days at 25°C and 90% relative humidity. Elongated 1.0 to 2.5 cm x 0.5 to 0.9 cm lesions gray-brown/reddish-brown with a depressed center were observed in all inoculated cultivars. The fungus was reisolated and the characteristics of the colonies were identical to those previously isolated. For molecular characterization, DNA was extracted from the mycelia using the CTAB method (Doyle and Doyle 1990). End-point PCR was performed using GoTaq® Flexi DNA Polymerase (Promega, USA) and primer pairs, ITS-4F/ITS-5, T2/Bt2b and EF1-728F/EF1-986R to amplify the internal transcribed spacer (ITS) (Costamilan et al. 2008), β-tubulin (TUB2) (Glass and Donaldson 1995), and translation elongation factor 1-α (TEF1) (Carbone and Kohn 1999) genes, respectively. The amplified fragments were sequenced and submitted to blast search (https://blast.ncbi.nlm.nih.gov/Blast.cgi) with the sequences available in GenBank. The fragment from ITS (accession number OR912979) showed 99.8% (549/582 bp) identity with Diaporthe ueckeri Udayanga & Castl. [as 'ueckerae'] [syn. D. miriciae R.G. Shivas, S.M. Thomps. & Y.P. Tan] isolate FAU656 (Ac. N. KJ590726). The sequence of TEF (Ac. N. PP372869) showed 99.7% (339/355 bp) identity with D. ueckeri FAU656 (Ac. N. KJ590747), and of TUB (Ac. N. PP372870) showed 98.9% (436/536 bp) identity with D. ueckeri FAU656 (Ac. N. KJ610881). A phylogenetic tree with amplified sequences of each gene and the corresponding representative sequences from the DPC was constructed in MEGA X (Kumar et al. 2018). The MEMR0500 isolate was clustered only with the D. ueckeri clade, confirming the identity of the fungus (Figure S2). In Brazil, this is the first report of the association of this pathogen with soybean seeds. In other countries, this pathogen has been identified as the causal agent of stem canker (Mena et al. 2020; Lopez-Cardona et al. 2021). Further research is needed to analyze the risk of this seed-associated pathogen.

Cotton bacterial blight (CBB), caused by Xanthomonas citri pv. malvacearum, was a major disease of cotton in the United States in the early part of the twentieth century. The reemergence of CBB revealed many gaps in our understanding of this important disease. In this study, we employed a wild-type (WT) field isolate of X. citri pv. malvacearum from Georgia (U.S.A.) to generate a nonpathogenic hrcV mutant lacking a functional type-III secretion system (T3SS-). We tagged the WT and T3SS-strains with an auto-bioluminescent Tn7 reporter and compared colonization patterns of CBB-susceptible and CBB-resistant cotton seedlings using macroscopic image analysis and bacterial load enumeration. WT and T3SS- X. citri pv. malvacearum strains colonized cotton cotyledons of CBB-resistant and CBB-susceptible cotton cultivars. However, X. citri pv. malvacearum populations were significantly higher in CBBsusceptible seedlings inoculated with the WT strain. Additionally, WT and T3SS- X. citri pv. malvacearum strains systemically colonized true leaves, although at different rates. Finally, we observed that seed-toseedling transmission of X. citri pv. malvacearum may involve systemic spread through the vascular tissue of cotton plants. These findings yield novel insights into potential X. citri pv. malvacearum reservoirs for CBB outbreaks. [ABSTRACT FROM AUTHOR]

Abstract This study aimed to evaluate the effect of atmospheric plasma application on the inactivation of fungi on the surface of Erythrina velutina seeds and on isolated fungal colonies. Two experiments were conducted using a completely randomized design. First, plasma was applied to the surface of the seeds using helium gas and atmospheric plasma for 3, 6, and 9 min in addition to the control (untreated seeds), constituting seven treatments with five repetitions each. In the second experiment, Petri dishes containing the inoculum of different fungi were treated with atmospheric air plasma for 3, 6, and 9 min (Air-3, Air-6, and Air-9) and were compared with untreated fungi in Petri dishes without treatment (control), totaling four treatments and five repetitions each. We found that the application of atmospheric air plasma to E. velutina seeds for 9 min had an antimicrobial effect on the fungi Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp., and Rhizopus sp. The formation of fungal colonies isolated from E. velutina seeds was also inhibited by 3 min of exposure to atmospheric air plasma, except for A. niger, whose inhibition occurred after 6 min of exposure to atmospheric plasma.

Soybean (Glycine max) is an important commodity for the Brazilian economy. However, Colletotrichum truncatum is considered to play a significant role in reducing germination and vigor of soybean seed. This study aimed to determine the optimal temperature for pathogen growth, to verify the effect of different seed inoculum potentials in soybean seed germination and pathogen incidence under controlled conditions. We evaluated the maximum mycelial growth on modified potato dextrose agar at 18, 21, 24, 27, and 30 °C. For inoculum potential assessment, the seeds were exposed to the pathogen for 0, 24, 48, 72, and 96 h under the optimal temperature of pathogen growth. It was found that the maximum mycelial growth temperature ranged from 27.0–29.3 °C among strains tested. A decrease in the germination percentage of soybean seeds was observed as inoculum potential increased. The incidence of the C. truncatum in the seeds was 100% at 48 h exposure time. This study provides an overview of the risk of using soybean seeds with high inoculum potential, since longer exposure times to the pathogen led to more serious negative effects on seed germination and a higher incidence of the C. truncatum in the soybean seeds. [ABSTRACT FROM AUTHOR]

As for most plant species occurring in forests, Caesalpinia ferrea Mart. Ex Tul. has been presenting some phytosanitary problems, and thus research efforts have been increased considering the use of alternative treatments using as basis essential oils like Thymus vulgaris L., which is responsible for antimicrobial activity. The objective of this study was to evaluate the influence of the essential oil from thyme on the sanitary and physiological quality of ironwood seeds. The experiment was carried out in a completely randomized design with four repetitions with 50 seeds. The treatments considered the use of the thyme essential oil at concentrations of 0, 2, 4, 6, 8, and 10%. The ironwood seeds were obtained from matrices taken at random, moved to the laboratory, where sanitary evaluations were carried out using the Blotter test method in 25±2°C temperature and in a 12h photoperiod. After 7 days, with the aid of a microscope, fungi were identified. Next, physiological analysis were conducted -- germination, first count of germination, and germination speed index. Measurements of the shoot and root parts of the seedlings, shoot dry matter, and root dry matter were taken. According to the obtained results in this work, it was verified that the T. vulgaris dry matter in all concentrations presented different results, noting that when the oil concentration increases, the occurrence of pathogens decreases, which proves that the T. vulgaris essential oil has specific action on some genera of fungi. [ABSTRACT FROM AUTHOR]

ABSTRACT: Knowledge of the effect of the seedborne inoculum is important for knowing the level of tolerance of the pathogen by the seed. This research evaluated the effect of the incidence of the fungus Microdochium albescens on the physiological quality of the seeds of different cultivars of irrigated rice. The study was carried out in the seed testing laboratory (STL), phytopathology laboratory and in greenhouse, located at the Center of Agroveterinary Sciences of the Santa Catarina State University, Lages, SC, Brazil. Seeds from six irrigated rice cultivars produced in the Alto Vale do Itajaí Region in the 2016/17 harvest, were used. The lots were submitted to the seed health test, identifying four lots per cultivar with a natural incidence of M. albescens, with two lots of each cultivar with an incidence greater than 40% and two lots equal or less than 40%, totaling 24 seed lots. The following evaluations were carried out on the lots: germination, accelerated aging test, emergence in a greenhouse at 14 days, emergence speed index (ESI), emergence speed (ES), shoot length, root length and fresh and dry mass. There was a significant interaction between cultivar and level of incidence only in the variables germination, vigor and root length. Fresh mass, shoot length and ESI were not affected, regardless of cultivar and incidence of fungus in the seed. The irrigated rice cultivars SCS118 Marquês and SCSBRS Tio Taka are susceptible to a high incidence (> 40%) of the fungus M. allbescens.

Seeds of three important cucurbit species (cucumber, melon and zucchini) were obtained through on-line mail-order providers and tested for selected viruses of biosecurity and agronomic concern. One or more of the targeted viruses were detected in 23 of the 31 seed lots tested. The quarantine pest melon necrotic spot virus was detected by ELISA in melon seeds. Multiple instances of contamination with the quarantine pest cucumber green mottle mosaic virus were also detected, and its presence in seeds of all three plant species was confirmed by inoculation and re-isolation from indicator plants. Cucumber mosaic virus, squash mosaic virus and potyviruses were repeatedly detected, and instances of insect pest and plant trash contamination were also observed. Seeds imported into Australia from some on-line sources have potential to introduce organisms of biosecurity concern. [ABSTRACT FROM AUTHOR]

Blast, caused by Pyricularia oryzae, on wheat can negatively impact yield. This study investigated the effect of blast on seed germination and kernel weight of seeds obtained from the infected spikes of plants from the wheat cultivars BR-18 (moderately resistant) and BRS-Guamirim (susceptible). Spikes of each plant were inoculated at anthesis (0) as well as at 7, 14, and 21 days after anthesis (daa) with a conidial suspension of P. oryzae. Non-inoculated spikes served as the control treatment. Seed germination and the weight of 1000 seeds were determined. Based on regression analyses, blast severity was great both at anthesis and 7 daa causing great reductions on seed germination and weight of 1000 seeds. Blast severity in the spikes of plants from cultivar BR-18 was reduced by 38, 35, 45, and 41% at anthesis and at 7, 14, and 21 daa, respectively, in comparison to spikes from plants of cultivar BRS-Guamirim. Blast severity was lower on spikes from 14 to 21 daa in comparison to anthesis and caused less impact on seed germination and weight of 1000 seeds. In conclusion, the negative effect of blast on seed germination and weight of 1000 seeds was dependent on the level of basal resistance of each cultivar and the time when the spikes were infected by P. oryzae. [ABSTRACT FROM AUTHOR]

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.

Abstract There has been an increase in the occurrence of fungal diseases in Ilex paraguariensis A. St.-Hill. (yerba mate) resulting from their domestication. Seed health tests may indicate pathogens prior to sowing, enabling their control. Our study sought to compare the efficacy of fungi detection methods on yerba mate seeds. Seeds from four lots were subjected to the following detection methods: BDA, V8 and filter paper; as well as the performance of asepsis with 1% sodium hypochlorite and 70% alcohol. The fungi found in the lots were: Penicillium spp., Cladosporium spp., Aureobasidium melanogenum, Aspergillus spp., Pestalotia spp., Nigrospora spp., Trichoderma spp., Fusarium graminearum, F. oxysporum and F. guttiforme. The asepsis in the seeds reduced the occurrence of contaminating organisms. There were differences between the evaluated lots regarding fungal incidence. In general, the BDA and V8 culture media showed better results in fungal detection.

The purpose of seed conditioning process is to separate seeds and their associated structures into different fractions and retain only good and healthy seeds. Thus, the aim of this study was to evaluate the effects the stages of seed conditioning have on the sanitary quality of marandu grass seeds. The seeds were sampled before and during the seed conditioning process, i.e., after exiting the air-screen cleaner and sieves (seeds discharged from the top, middle and bottom sieves), the first gravity separator (seeds drifting around the table, upper and intermediate discharge) and second gravity separator (upper, intermediate and lower discharge). The sanitary analysis was performed using the filter paper method with and without surface disinfestation of the seeds, which were incubated at 20±2°C, with a photoperiod of 12 hours for seven days. The experiment was conducted in a completely randomized design, in a 2x6 factorial scheme (surface disinfestation x stages of the seed conditioning process) and ten replications. The data was submitted to analysis of variance, using the F test and, when significant, the means of the treatments were compared using the Tukey test at 5% probability. It was concluded that it is not possible to improve the sanitary quality of marandú grass seeds through the seed conditioning process.

'Peroba rosa' (Aspidosperma polyneuron Muell. Arg.) is a forest species native to Brazil, which is threatened of extinction due to intense predatory exploitation. Knowing the physiological and sanitary aspects of the seeds or seedlings of native species is essential to determine the viability of the establishment of seedlings and natural regeneration. In tropical regions such as Brazil, the susceptibility of phytopathogens in native forest species is still poorly understood. In this work, we report for the first time Fusarium species associated with pathogenicity in Aspidosperma polyneuron. We identified a diverse group of crop pathogens Fusarium species - F. solani, F. oxysporum, F. verticillioides, F. equiseti, F. fujikuroi, F. pseudocircinatum and F. subglutinans from seeds, able to cause darkening of the leaf limb of inoculated seedlings. These results provide valuable information on the pathogenic association of Fusarium with an indigenous forest tree and possible risks these fungi might pose to the forest species. [ABSTRACT FROM AUTHOR]

ABSTRACT Peroba rosa (Aspidosperma polyneuron) is a native forest species endangered due to intense predatory exploitation. The objective of this study was to evaluate the association and fungi transmission in peroba rosa seeds from four regions of Paraná. Germination and vigor were evaluated using the paper roll method. Sanitary analysis consisted of the detection of endophytic and epiphytic fungi using potato-dextrose-agar medium and Fusarium selective medium. For transmission, non-disinfested seeds were sown in vermiculite and kept in greenhouse. Germination ranged from 9.3% to 60%. Fusarium sp. and Phomopsis sp. were found as epiphytic and also as endophytic. There was transmission of Fusarium sp. and Phomopsis sp. from seeds to seedlings, causing malformation and necrosis on roots and cotyledons.

ABSTRACT: The objective of this work was to conduct a temporal evaluation of incidence of rot base and sanitary severity, and to relate the impact on the seed pathology of common bean cultivars. In the 2015-2016 harvest, in the city of Ipameri, Goiás, ten cultivars of common bean were evaluated (BRS Estilo©, BRS Pérola©, IPR Tangará©, IPR Tuiuiú©, IPR Uirapuru©, IAC Milênio©, Imperador©, IAC F3 R2©, IAC OTG© and IPR Campos Gerais©) and distributed into five blocks, totaling 40 experimental units. The incidence of wilt and base rot and sanitary severity were analyzed by taking ten random samples per block at 21, 28, 56, 63 and 69 days after planting. At the end of 120 days, a total of 20 plants were harvested per cultivar, and 250 seeds were harvested for application of the Blotter Test method. From 21 to 69 days after planting, the cultivars BRS Pérola© and IPR Campos Gerais© deserve to be highlighted for presenting the lowest incidence of wilt in the reproductive and vegetative cycles. The cultivar BRS Pérola© showed the lowest incidence of wilt and sanitary severity. In the analysis of harvested seeds, the cultivar BRS Pérola© presented high physiological quality for all evaluated parameters. On the other hand, Cramberry (OTG)© showed low physiological potential in germination and vigor tests.

This study was carried out towards the development of rapid PCR-based assays for detection and identification of Colletotrichum truncatum, C. gloeosporioides sensu lato and Fusarium sp. infecting green and red bell pepper seeds in Trinidad using DNA templates produced by automated grinding and robotic paramagnetic particle capture. DNA was extracted from freshly collected symptomatic green and red bell pepper seeds using Promega's Maxwell® 16 robotic system. The PCR assay of 220 seeds harvested from field-infected bell pepper fruit compared different optimization parameters including seeds that were symptomatic and asymptomatic of infection, the relative success of two different DNA polymerase enzymes, genus-specific and species-specific primers that were pre-existing in the literature in addition to primers that were newly designed for this study and duplex PCR for the simultaneous detection of DNA templates belonging to two different fungal species. The findings indicated that seeds carried dual infections of C. truncatum and Fusarium sp. Compared to other primers that were screened, our newly designed primers, ITS219-F/ITS419-R with GoTaq® Green Master Hot Start Taq DNA Polymerase, detected C. truncatum in the highest number of symptomatic seeds of infected green and red bell pepper fruit as well as in asymptomatic seeds of infected red bell pepper fruit. Fusarium sp. was detected only in red bell pepper seeds. Duplex PCR using ITS219-F/ITS419-R and Fa/Ra primers successfully simultaneously detected and identified C. truncatum and Fusarium sp. in symptomatic seeds of infected red bell pepper fruit. None of the seeds were infected with C. gloeosporioides sensu lato which is currently considered to be a minor pathogen in bell pepper in Trinidad. PCR-based detection methods are key tools in the detection and identification of fungal plant pathogens especially where seeds are an important inoculum source. The molecular approach as optimized in this study, is faster, more sensitive and the presence of single or dual fungal infections can be assessed in one assay. [ABSTRACT FROM AUTHOR]

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The quality of seeds produced is the result of the management practices used and environmental conditions during growing. The aim of this study was to evaluate the physiological potential and the health of soybean seeds produced in an organic and conventional system. The genotypes UEL 110 and 122 and BRS 257 and 284 were tested in organic and conventional systems in a randomized block design. The following characteristics were evaluated: moisture content; thousand seed weight (TSW); germination (G) and first count of germination (FCG); tetrazolium (TZ); classification, length, and dry matter of seedlings; and seed health. Analysis of variance was performed separately for the management systems, followed by combined analysis. When significant, the Tukey test (p<0.05) was applied. Multivariate analysis was performed using R software. There was not significance between genotypes and management systems. The conventional management system performed positively for the characteristics TSW, G, TZ, FCG, classification, and length and dry matter of seedling roots, as well as for plant health. The UEL genotypes obtained higher TSW; UEL 110, lower germination; and BRS 257, a smaller number of ungerminated seeds and higher infestation by Cladosporium spp. The seeds produced under the organic system have greater weight and lower infestation by contaminants, whereas the conventional system produces seeds of better physiological quality and lower contamination by Phomopsis and bacteria. The genotype BRS 257 may have seeds multiplied in the organic and conventional management systems. [ABSTRACT FROM AUTHOR]

The fungi Aspergillus sp., Penicillium sp., Fusarium sp. and Stenocarpella macrospora are pathogens frequently associated with the complex of diseases responsible for spike rot and incidence of burned grains in susceptible hybrids. In view of the above, the objective of this study was to evaluate the influence of the percentage of burned grains on the sanitary quality of corn grain lots (Zea mays L.), from the field of production and submitted to irrigation and two sowing systems. The experimental design was completely randomized, with four treatments (lot I = with irrigation and conventional seeding system, lot II = with irrigation and direct seeding system, lot III = no irrigation and conventional seeding system, lot IV = no irrigation and no-tillage system), in four replications. The corn grain lots were evaluated for the percentage of burned grains and the incidence of fungi (Blotter test). There was a significant difference between the different corn grain lots for all analyzed variables. The highest percentage of burned grains and the incidence of fungi Penicillium sp., Fusarium sp. and Aspergillus sp. were observed in the lots from the production fields conducted with irrigation. The higher the percentage of burned grains, the higher the incidence of fungi Penicillium sp. and Fusarium sp., in the corn grain lots, these variables showed a high positive correlation between the percentage of burned grains and incidence of fungi. [ABSTRACT FROM AUTHOR]

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Rodents influence plant establishment and regeneration by functioning as both seed predators and dispersers. However, these rodent–plant interactions can vary significantly due to various environmental conditions and the activity of other insect seed predators. Here, we use a combination of both field and enclosure (i.e. individual cage and semi‐natural enclosure) experiments, to determine whether rodents can distinguish sound seeds from those infested with insects. We also demonstrate how such responses to insects are influenced by food abundance and other environmental factors. We presented rodents with 2 kinds of Quercus aliena seeds (sound and insect‐infested seeds) in a subtropical forest in the Qinling Mountains, central China, from September to November of 2011 to 2013. The results showed that rodents preferred to hoard and eat sound seeds than infested seeds in the field and semi‐natural enclosure, while they preferred to eat infested seeds over sound seeds in the individual cages. In addition, both hoarding and eating decisions were influenced by food abundance. Rodents hoarded more sound seeds in years of high food abundance while they consumed more acorns in years of food shortage. Compared with field results, rodents reduced scatter‐hoarding behavior in semi‐natural enclosures and ate more insect‐infested seeds in smaller individual cages. These results further confirm that rodents distinguish infested seeds from non‐infested seeds but demonstrate that this behavior varies with conditions (i.e. environment and food abundance). We suggest that such interactions will influence the dispersal and natural regeneration of seeds as well as predation rates on insect larvae. [ABSTRACT FROM AUTHOR]

In the present study the aspects of discolouration that could influence both the production and consumption of amaranth were analyzed with the objectives to identify the presence of Alternaria alternata on seeds, to analyze possible changes in the anatomy of seed tissues and to detect the presence of fungal secondary metabolites. Component plating, histopathological and mycological analyses on discoloured seeds allowed i) location of propagules of A. alternata in all seminal components; ii) observation of hypertrophies in perisperm and embryo and iii) determination of several fungal secondary metabolites, mainly high concentrations of tenuazonic acid. To our knowledge, the information presented in this paper, related to physiological, histopathological changes and fungal secondary metabolites on discoloured seeds of (Amaranthus mantegazzianus syn. A. caudatus subsp. mantegazzianus (Pass) Hanelt affected by A. alternata, is the first worldwide record.

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%.

Conventional methods for detecting seed-borne fungi are laborious and time-consuming, requiring specialized analysts for characterization of pathogenic fungi on seed. Multispectral imaging (MSI) combined with machine vision was used as an alternative method to detect Drechslera avenae (Eidam) Sharif [Helminthosporium avenae (Eidam)] in black oat seeds (Avena strigosa Schreb). The seeds were inoculated with Drechslera avenae (D. avenae) and then incubated for 24, 72 and 120 h. Multispectral images of non-infested and infested seeds were acquired at 19 wavelengths within the spectral range of 365 to 970 nm. A classification model based on linear discriminant analysis (LDA) was created using reflectance, color, and texture features of the seed images. The model developed showed high performance of MSI in detecting D. avenae in black oat seeds, particularly using color and texture features from seeds incubated for 120 h, with an accuracy of 0.86 in independent validation. The high precision of the classifier showed that the method using images captured in the Ultraviolet A region (365 nm) could be easily used to classify black oat seeds according to their health status, and results can be achieved more rapidly and effectively compared to conventional methods.

The Dimorphandra gardneriana Tul. species is widely distributed in the Brazilian territory presenting an economic and environmental importance. The aim of this study was to determine the fungi associated with Dimorphandra gardneriana seeds, assessing the influence of nystatin, the castor oil plant and Captan® fungicide in the control of these fungi in the seed germination and seedlings growth. The experiment was carried out at the Laboratório de Fitopatologia and Análise de Sementes of the Departamento de Fitotecnia e Ciências Ambientais of Centro de Ciências Agrárias of the Universidade Federal da Paraíba, Areia-PB, Brazil. Ten treatments were applied for mycoflora control: T1 - control (untreated seeds); T2 - nystatin (0.1%); T3 - nystatin (0.2%); T4 - nystatin (0.3%); T5 - nystatin (0.4%); T6 - castor bean oil (0.25%); T7 - castor bean oil (0.5%); T8 - castor bean oil (0.75%); T9 - castor bean oil (1%); T10 - fungicide Captan®. For the evaluation of the effect of the treatments on the Dimorphandra gardneriana seeds the following variables were evaluated: germination, first counting of germination and germination speed index, percentage of abnormal seedlings, length and dry matter of shoots and roots of seedlings. Nystatin (0.1%) reduced the incidence of Aspergillus sp. The Captan® fungicide reduced the incidence of fungi in the seeds and provided the best results for germination and vigor.

Pythium seedling blight, which can be caused by a number of Pythium spp., is a disease that affects soybean (Glycine max) in the United States and Canada. Pythium ultimum var. ultimum, one of the most common pathogenic species, is favored by cool, wet conditions in early spring and causes seed decay, root rot, and seedling damping-off. In all, 102 major ancestors of modem North American cultivars and "first progeny" cultivars developed directly from ancestral lines were evaluated for resistance to P. ultimum var. ultimum and two other species of Pythium in greenhouse assays. Several ancestors and first progeny cultivars, as well as the resistant check Archer, had varying levels of partial resistance to an Illinois isolate of P. ultimum var. ultimum. In a subsequent experiment, four of the most resistant lines (PI 84637, Maple Isle, Fiskeby 111. and Fiskeby 840-7-3) and the susceptible cultivar Kanro were screened for resistance against isolates of P. irregulare and P. sylvaticum, and resistance to P. ultimum var. ultimum was confirmed. The lines that were partially resistant to P. ultimum var. ultimum in the first experiment were also partially resistant to P. irregulare and P. sylvaticum. The P. ultimum var. ultimum isolate was the most aggressive of the three isolates, followed by the P. irregulare and P. sylvaticum isolates. Modern cultivars descended from the soybean lines with partial resistance to these pathogens could be useful sources of resistance to Pythium seedling blight if they are found to have similar levels of resistance. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the transmissibility of Fusarium oxysporum f.sp. vasinfectum by inoculated cottonseeds. The cottonseeds were inoculated using the water restriction technique, at different times of exposure. A completely randomized design was used in the laboratory and a randomized design with blocks was used in the field experiment, with a 2x5 factorial arrangement with two cultivars (FMT 701 and Delta Opal) and five times of exposure of the pathogen in seeds (0 h, 24 h, 48 h, 72 h and 96 h). There was a reduction in the percentage of germination with the increase of the infection of the seeds when in greater time of contact with the fungus. Delta Opal cultivar presented minor disease index and major pathogen incidence when compared to FMT 701 cultivar. The rates of infection and transmission of the seed pathogen were effective and directly proportional to the inoculum potential in the seeds, with rates of 95% and 1.2%, respectively. [ABSTRACT FROM AUTHOR]

An experiment was conducted during 2014-2015 to standardize the seed testing method in Kabuli chickpea MNK-1 by number of seeds and number of germination papers. Among the different testing methods 25 seeds per replication recorded highest seed germination percentage (91.58%), less number of fresh un-germinated seeds (1.91%), abnormal seedlings (4.00%), diseased seeds (2.33%) and significantly higher seedling vigour index-I and II (2215 and 6863), among the number of germination papers used 2+1 as in between paper method(Bottom 2 and one paper above) recorded significantly higher germination percentage (92.12%), less number of fresh un-germinated seeds (1.41%), abnormal seedlings (3.66%), diseased seeds (2.33%) and significantly higher seedling vigour index-I and II (2463 and 6900), when compared to other. Irrespective of number of germination paper and seeds used however, interaction of 25 seeds per replication and 2+1 between paper method of seed germination testing showed significantly germination percentage (96.50%), less number of fresh un-germinated seeds (0.00%), abnormal seedlings (1.00%), diseased seeds (1.00%) and significantly higher seedling vigour index-I and II (2844 and 7792) followed by 50 seeds per replication. [ABSTRACT FROM AUTHOR]

Abstract: Fungi of the Trichoderma spp. genus, notably Trichoderma harzianum, are commonly used for biological management of deleterious seed‐ and soil‐borne pathogens. The global biopesticides market is booming with a major share of various commercial formulations of T. harzianum. However, there are some major drawbacks associated with these commercial formulations including short shelf life, low on‐field stability and irregular performance in different agro‐climatic regions. For effectively resolving these issues, new strategies are urgently required for efficient management of pathogens. The present review provides an overview of the use of Trichoderma spp., with special emphasis on T. harzianum, and discusses future trends for biological control. Technologies are described for the microencapsulation of fungi and for the biogenic synthesis of nanoparticles, with the aim of improving the biological control of pathogens and contributing to sustainable agricultural practices. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

One of the rarer problems that occur in growing medicinal and spice plants is ensuring the quality of the propagating material. Germination of seeds of one of these plants, Allium ursinum L., is slow. To improve that, stratification is used. In the experiment, which was carried out in Lithuania in 2016, evaluation of four-and five-week long stratification and the use of alkaline ionized (pH 8.6) water for germination affect for Allium ursinum L. seeds were evaluated. It was found that the above-mentioned intervals for stratification did not affect the beginning of seed germination. Furthermore, one of the possible reasons for slower germination was found, and it was the incidence of seed diseases caused by fungi and bacteria. Allium ursinum L. seeds were affected the most by Penicillium ssp. micromycetes. The longer the period of stratification, the more alkaline ionized water decreased the effect of Mucor ssp. Micromycetes. [ABSTRACT FROM AUTHOR]

Wheat and chickpea are considered the most important sources of food and energy and stored for longer period of time in the rural areas in the farmers sheds as seed for the next crop and as market commodity to sale. Both of these crops are liable to many mycoflora which not only deteriorate their quality but also leads toward the crop failure during the coming season. A number of seed borne pathogens viz., Aspergills niger, Aspergillus flavus, Aspergillus sulphureus, Aspergillus nidulense, Rhizopus stolonifer, Penicillium spp. and Drechslera spp, were isolated from wheat seed samples while Aspergillus niger, Aspergillus flavus, Bipolaris spp., Penicillium spp. and Rhizopus stolonifer were isolated from seed samples of chickpea. Various broad spectrum fungicides were evaluated against the isolated mycoflora which showed significant result. Score, Topsin-M and ridomil gold to be the most significant fungicides at all doses against the isolated mycoflora. [ABSTRACT FROM AUTHOR]

This study was conducted to estimate the infection of Bruchophagus roddi in 66 alfalfa fields in Igdir, Turkey during the month of August in 2014-2015, and to determine infection preferences of B. roddi for number of pods in a bunch (NPB) and number of seeds in a pod (NSP). CHAID algorithm was preferred in the prediction of the number of seeds damaged (NSD) through district, year, NPB and NSP. In Aralik district, B. roddi preferred the seeds of varieties with NSP⩽3.8 (0.858 NSD) at lower rate in 2015. In Karakoyunlu, Tuzluca and Central districts in 2015, varieties with NPB>11 were preferred less but varieties with 910 were preferred less but varieties whose NSP was greater than 7.6 were preferred at the highest proportion by B. roddi in Aralik district in the 2015. [ABSTRACT FROM AUTHOR]