Peronospora Manshurica Research Articles

Transcription-Aided Selection (TAS) for Crop Disease Resistance: Strategy and Evidence

A transcription-aided selection (TAS) strategy is proposed in this paper, which utilizes the positive regulatory roles of genes involved in the plant immunity pathways to screen crops with high disease resistance. Increased evidence has demonstrated that upon pathogen attack, the expression of diverse genes involved in salicylic acid (SA)-mediated SAR are differentially expressed and transcriptionally regulated. The paper discusses the molecular mechanisms of the SA signaling pathway, which plays a central role in plant immunity, and identifies differentially expressed genes (DEGs) that could be targeted for transcriptional detection. We have conducted a series of experiments to test the TAS strategy and found that the level of GmSAGT1 expression is highly correlated with soybean downy mildew (SDM) resistance with a correlation coefficient R2 = 0.7981. Using RT-PCR, we screened 2501 soybean germplasms and selected 26 collections with higher levels of both GmSAGT1 and GmPR1 (Pathogenesis-related proteins1) gene expression. Twenty-three out of the twenty-six lines were inoculated with Peronospora manshurica (Pm) in a greenhouse. Eight showed HR (highly resistant), four were R (resistant), five were MR (moderately resistant), three were S (susceptible), and three were HS (highly susceptible). The correlation coefficient R2 between the TAS result and Pm inoculation results was 0.7035, indicating a satisfactory consistency. The authors anticipate that TAS provides an effective strategy for screening crops with broad-spectrum and long-lasting resistance.

Leaf-stem diseases of soybean on varieties of diferent ripenity groups in the conditions of the Amur region

The Amur region is the main producer of soybeans in the Russian Federation, where one of the significant phytosanitary problems of soybean cultivation technologies is leaf and stem infections. The susceptibility of soybeans to diseases varies greatly depending on weather conditions, used agricultural technology and the resistance of cultivated varieties. Since the soybean varieties, cultivated in the region, have significant differences in early maturity, it remains relevant to monitor leaf and stem infections and identify the degree of their development depending on the length of the crop growing season and the year conditions. The purpose of the study was to assess the influence of soybean variety by maturity groups and year conditions on the incidence of leaf-stem infections. Research was carried out in 2022 and 2023 in the Tambov district of the Amur region on 32 soybean varieties of domestic and foreign selection, belonging to 3 ripeness groups: early ripening, mid-ripening and late ripening. A phytopathological examination of soybean crops revealed Septoria blight (Septoria glycines T. Hemmi. Syn.), Cercospora blight (Cercospora sojina Hara), Ascochyta blight (Ascochyta sojaecola Abramoff. Syn.), downy mildew (Peronospora manshurica (Naum.) Syd. Syn.), purple Cercospora blight (Cercospora kikuchii (Matsuet Tomoyasu) Yardn) and angular bacterial spot. According to the indicator of disease incidence on soybean varieties of three ripeness groups, it was revealed that the incidence of downy mildew significantly, at the level of 90 %, depended on the variety ripeness group: mid-, and especially late-ripening varieties, were affected by the disease in both years an order of magnitude more strongly than early-ripening varieties. No significant influence of soybean varieties maturity groups on other infections was detected after the use of the fungicide, while analysis of variance according to the two-factor experiment scheme showed a significant influence of year weather conditions on the diseases incidence: Cercospora blight – at the level of 75.7 %, Cercospora purple blight – 77.1 %, Ascochyta blight – 98.5%. Both the ripeness group of soybean varieties and the year conditions influenced the bacteriosis incidence: the disease was more pronounced on early-ripening varieties, which were more populated by mites, the vectors of the disease pathogen, and was noted only in 2023. Analysis of variance according to the two-factor experiment scheme did not reveal a significant influence of varieties and year conditions on the incidence of Septoria blight, which indicates significant adaptations of the pathogen to weather factors and the physiology of plants from different ripeness groups, as well as the stable effectiveness of fungicidal treatment of soybean crops against Septoria blight.

Quarantine pathogen interceptions on crop germplasm in India during 1986 - 2010 and their possible economic impact

The National Bureau of Plant Genetic Resources Regional Station, Hyderabad has facilitated safe introduction of 356 521 (1986–2010) germplasm accessions of various crops into India. About 60 seed-borne pathogens of quarantine importance were intercepted on crop germplasm during seed examination in the laboratory and post-entry quarantine observations in the field. Of these, the quarantine pathogens, viz. Ralstonia solanacearum and peanut stripe virus in groundnut (Arachis hypogaea L.), Peronospora manshurica (Naum.) Syd. and peanut stripe virus in soybean [Glycine max (L.) Merr.], tobacco streak virus in sunflower (Helianthus annuus L.), Xanthomonas campestris pv holcicola (Elliot) Dye, Burkholderia andropogonis (Smith) Gillis et al. on sorghum [Sorghum bicolor (L.) Moench], Drechslera maydis (Nisik.) Subram. & Jain on maize (Zea mays L.) and Pseudomonas syringae pv tomato (Okabe) Young et al. on tomato (Lycopersicon esculentum Mill.) were intercepted from different countries. Yield losses that could have occurred were estimated had these pathogens of groundnut, soybean, sunflower, maize, sorghum and tomato not been intercepted.

Quadruplex and q-PCR based diagnostic assay to delineate the major quarantine and other seed-borne fungal pathogens of soybean.

Soybean is one of the most important crops grown worldwide and accounting for significant global trade including transgenic soybean. The crop is attacked by several seed-borne fungal pathogens and some of them are of quarantine concern for India. Keeping in view of the risks associated with movement of soybean seeds, sensitive and reliable molecular diagnostics have been developed for precise and simultaneous detection of three pathogens of quarantine concern for India namely, Diaporthe phaseolorum (stem blight), D. longicolla (seed decay), Peronospora manshurica (downy mildew), along with Macrophomina phaseolina causing dry root rot. The targeted pathogens after isolation from imported transgenic and non-transgenic soybean seeds were identified. Quadruplex and qPCR assays were developed targeting the sequences of different genes such as Histone-3 for detection of D. longicolla and M. phaseolina. The markers DlHisF2&R2 and MpHisF1&R1 produced 265 and 309bp amplicons for D. longicolla and M. phaseolina, respectively. Actin gene based marker DpActF1&R2 was developed for D. phaseolorum which provided 113bp amplicon whereas, COX2 based marker PmCoxF2&R2 was developed for P. manshurica with amplified product of 152bp. During qPCR analysis, these markers proved highly specific and sensitive for detection of these pathogens up to 0.1 pg of template DNA. Quadruplex PCR protocol was also developed by combining these specific markers which could distinguish all the targeted pathogens simultaneously in a single reaction. The developed diagnostic protocols are extremely valuable for quarantine clearance and to ensure the safe transboundary exchange and healthy conservation of germplasm in the National Genebank.

Detection of Peronospora manshurica in imported soybean and analysis of oospore viability in storage warehouses in Ternate City, Indonesia

The soybean needs of the people in Ternate are fulfilled by imported soybeans that enter through Surabaya. The process of transporting imported soybean seeds from Surabaya to the port of Ternate and storage in warehouses may lead to contamination with Peronospora manshurica fungus, which poses a risk of spreading to soybean crops in Ternate. This study aims to detect the presence of P. manshurica fungus, viability, and growth of P. manshurica oospores in the imported soybean storage warehouses in Ternate. The study was conducted using a combination of qualitative and quantitative methods. The qualitative method was carried out through an exploratory approach, while the quantitative method used a randomized block design (RBD) consisting of four treatments, i.e., G.Tbsi, G.Jbla, G.Tfra, and G.Tfrb, with five replications. The observation variables included disease occurance, presence, and characteristics of oospores, as well as oospore growth and viability percentage. The results showed that the average disease occurance in the soybean storage warehouses was highest in the sample of soybeans from the Tfrb warehouse at 1.88%, followed by the Jbla, Tfra, and Tbsi warehouses at 1.44%, 1.41%, and 1.24%, respectively. The study also found P. manshurica fungus in all four soybean storage warehouses in Ternate, with a viability percentage of G.Tbsi, G.Jbla, G.Tfra, and G.Tfrb were 25.8%, 28.8%, 27.4%, 26.5% respectively. These findings indicate the potential for disease spread to soybean crops in Ternate, thus necessitating appropriate preventive measures to address this problem.

Peronospora manshurica (soybean downy mildew)

Peronospora manshurica (soybean downy mildew)

Microbial diversity and volatile metabolites of kefir prepared by different milk types

ABSTRACT The presence of probiotic microbes and other health promoting nutritional characteristics of kefir increasing the consumer’s interest. The microbial as well as volatile profile of kefir are the two chief factors that determine the basis of quality kefir drink. In this study, we characterized the three milk kefir drinks prepared by sheep, goat and cow milk on the bases of amplicon-based sequencing for microbial diversity and volatile profile along with physio-chemical and colorimetric features. The bacterial and mycobiota analysis showed that the bacteria Acetobacter syzygii, Lactobacillus lactic and Lactobacillus plantarum and yeasts Kluyveromyces marxianus, Saccharomyces cerevisiae, Peronospora manshurica, and Pichia fermentans were predominantly found in sheep kefir which exhibited optimum physio-chemical colorimetric profile and maintained volatile compounds that play important role regarding antimicrobial and pleasant sensory profile of milk kefir. It is concluded that sheep milk significantly supported the probiotic and health promoting features of kefir.

Alternative Products to Control Soybean Downy Mildew in the Field

Soybean mildew caused by Oomycota Peronospora manshurica, is a disease widely spread in Brazil. In order to study the efficiency of soybean mildew control due to the application of alternative products and fungicide in the field, experiments were conducted in Ponta Grossa, PR, Brazil, during the 2013/2014 and 2014/2015 growing seasons. The design used was randomized blocks with four replications. The treatments were: 1-witness; 2-acibenzolar-S-methyl; 3-calcium; 4-micronutrients: copper, manganese and zinc; 5-micronutrients: manganese, zinc and molybdenum; 6-NK fertilizer; 7-Ascophyllum nodosum and 8-azoxystrobin + cyproconazole with the addition of Nimbus adjuvant. Four applications of alternative products (phenological stages V3, V6, R1 and R5.1) and two of fungicide (phenological stages R1 and R5.1) were performed. The mildew severity was estimated using a diagrammatic scale. The severity data made it possible to calculate the area under the disease progress curve (AUDPC). In the 2014/2015 harvest the disease was more severe. The control of downy mildew by the use of fungicide did not reduce the epidemic. The fungicide was not efficient in the two evaluated seasons. All tested alternative products reduced the disease severity and AUDPC in both seasons. The best results in reducing downy mildew were found with the application of acibenzolar-S-methyl, micronutrients (Cu, Mn, Zn) and A. nodosum.

Raznolikost fitopatogenih gljiva na semenu soje u Srbiji

Soybean is one of the most important industrial crops in the world. The rich nutritional content of the seed is the reason for the increased cultivation of this crop all over the world. However, a large number of phytopathogenic fungi that exist in soybean seeds can reduce the nutritional content, germination, and seed vigor. Soybean seed samples were collected from experimental fields in seven locations in Vojvodina Province, Serbia in the period 2016-2018. From each sample, 100 seeds were randomly selected. Seeds were surface-disinfested in 4% sodium hypochlorite for 5 min, washed two times in sterile water, and dried on a filter paper. All 100 seeds were placed in 20 Petri dishes with standard potato dextrose agar medium (PDA), five seeds in each, and incubated at 22 ± 2°C for seven days, under 12 h of alternating light/dark conditions. The first assessment was performed on the fourth day after isolation. The health status analysis of soybean seed showed that Peronospora manshurica, Macrophominaphaseolina, Botrytis cinerea, Cercospora kikuchii as well as the species from genera Alternaria, Diaporthe, and Fusarium had colonized soybean seed in Serbia over three years. Species from the genus Alternaria and Peronospora manshurica were dominant in all three examined years. Furthermore, it has been noticed that weather conditions, location, and cultivar significantly influenced the intensity of the infection. The results of this study have shown which pathogens pose a threat to successful soybean seed production and help in finding preventive measures to control these pathogens during vegetation.

SOYBEAN INTEGRATED PEST MANAGEMENT FOR PROMOTING SUSTAINABLE AGRICULTURE UNDER CLIMATE CHANGE

"In order to protect agroecosystems and to optimize soybean crop yield from the Transylvanian Plain, the adoption of complex methods of sustainable management with minimal impact on the environment has now become a challenge. Therefore, an experiment was conducted at the Agricultural Research-Development Station Turda in 2018, to provide the best methods for the development of an Integrated Management System (IMS) for phytosanitary soybean crop risks. The field factorial experiment was based on a subdivided parcel design with two replications. Experimental models for soybean crop protection have been developed. Field research was carried out for analyzing the technological (agricultural practices), biological (diseases, insects, pests) and environmental (climate change, methods of improving soil fertility with phytosanitary risk by applying environmentally friendly products) factors affecting soybean crop yield and quality. An entomological sampling strategy (pheromone traps, plant surveys) was used for evaluating the IMS environmental risk and methods for increasing plant resistance to biotic and abiotic stress factors were also studied. The obtained data was correlated with the production values for the 3 experimental factors: the tillage system, fertilization and treatments. The following pests were recorded, soil pests Coleoptera, Agriotes larvae, Opatrum, dipterans Delia platura and D. florilega, vectors of viruses and phytoplasmoses, cicadas, aphids, trips and the common red spider Tetranychus urticae, defoliating omissions Vanessa cardui, owls Autographa gamma, Mamestra suasa, M. oleracea, Agrotis segetum) etc. In the climatic conditions of 2018, most frequent pathogens were downy mildew (Peronospora manshurica and bacterial blight Pseudomonas glycinae."

PROTECTION OF THE SOYBEAN CROP AGROECOSYSTEM THROUGH INNOVATIVE TECHNOLOGIES

"Soybean is an important economical crop used for human consumption, animal feed and industrial raw material. Also, soybean is succesfully used in crop roatations with the main cereal crops because it’s biological nitrogen-fixing capabilities. A great diversity of pests and diseases including nematodes, insects and phytopathogenic fungi are known to affect soybean crop. From plant emergence to grain maturity, pests Tetranychus urticae and Etiella zinckenella, pseudofungi Peronospora manshurica and fungi Fusarium sp. and Botrytis cinerea can cause economic damage. In this study was evaluated the influence of tillage systems, different types of fertilizers and pesticide treatments on the most economical important diseases and pests of soybean crop in a field experiment at Agricultural Research and Development Station (ARDS Turda) in the climatic conditions of 2020. Teo TD, an early maturing soybean variety created at ARDS Turda, was used for the experiment. Based on the assessments made, soil tillage system, fertilization and control of pests and diseases have differently influenced the downy mildew and T. urticae attack. To reduce the attack of pathogens in soybean crop, the best technological option is plowing, balanced fertilization and application of fungicides, either without or in combination with an insecticide. The T. urticae populations developed on mineral, organic and green fertilized plants. Integrated control methods must combine agro-technical measures with the application of chemical treatments in accordance with the warning of the appearance of the first adults. "

Bacillus thuringiensis Combined With Fungicide Applications in the Management of Soybean Leaf Diseases

Asian soybean rust (ASR) caused by Phakopsora pachyrhizi is the main soybean leaf disease in Brazil. Downy mildew (Peronospora manshurica) and powdery mildew (Microsphaera diffusa) are important soybean foliar diseases of occurrence in Paraná state. To reduce severity and yield losses caused by soybean foliar diseases, this work aimed to verify the efficacy of different application doses of the commercial product Dipel® Bacillus thuringiensis (Bt), which is a biological insect controller, combined with number of Opera® fungicide (pyraclostrobin + epoxiconazole) intercalated applications, and to investigate the effect of the Bt Dipel® in the resistance induction of soybean. For this study, different methodologies were used, including in vitro, in vivo and field assays. The results showed that Bt Dipel® can reduce soybean foliar diseases by inducing β-1,3 glucanase enzime and phytoalexin gliceolin. The fungicide application in the experiment condition reduced yield losses.

Applications of Next-Generation Sequencing for Large-Scale Pathogen Diagnoses in Soybean.

Soybean (Glycine max) has become an important crop in Manitoba, Canada, with a 10-fold increase in dedicated acreage over the past decade. Given the rapid increase in production, scarce information about foliar diseases present in the province has been recorded. In order to describe the foliar pathogens affecting this legume, we harnessed next-generation sequencing (NGS) to carry out a comprehensive survey across Manitoba in 2016. Fields were sampled during the V2/3 (33 fields) and R6 (70 fields) growth stages, with at least three symptomatic leaves per field collected and subjected to RNA sequencing. We successfully detected several bacteria, fungi, and viruses known to infect soybean, including Pseudomonas savastanoi pv. glycinea, Septoria glycines, and Peronospora manshurica, as well as pathogens not previously identified in the province (e.g., Pseudomonas syringae pv. tabaci, Cercospora sojina, and Bean yellow mosaic virus). For some microorganisms, we were able to disentangle the different pathovars present and/or assemble their genome sequence. Since NGS generates data on the entire flora and fauna occupying a leaf sample, we also identified residual pathogens (i.e., pathogens of crops other than soybean) and multiple species of arthropod pests. Finally, the sequence information produced by NGS allowed for the development of polymerase chain reaction-based diagnostics for some of the most widespread and important pathogens. Although there are many benefits of using NGS for large-scale plant pathogen diagnoses, we also discuss some of the limitations of this technology.

Identification of Disease on Leaves Soybean using Modified Otsu and Learning Vector Quantization Neural Networks

Disease of the soybean crop is one of the obstacles to increase soybean production in Indonesia. Some of these diseases usually are found in the leaves and resulted to the crop become unhealthy. This study aims to identify disease on soybean leaf through leaves image by applying the Learning Vector Quantization (LVQ) algorithm. The identification begins with preprocessing using modified Otsu method to get part of the diseases on the leaves with a certain threshold value. The next process is to identify the type of disease using LVQ. This process uses the minimum value, the maximum value and the average value of the red, green and blue color of the image. The testing conducted in this study is to identify two diseases called Peronospora manshurica (Downy Mildew) and phakopsora pachyrhizi (Karat). The result of testing by using 60 training data and the value of all recommendations parameters obtained the highest accuracy of identification is 95% %, but the more stable accuracy is 90%. This result shows that the method perform quite well identification of two mentioned disease.

Transcriptome analysis of soybean WRKY TFs in response to Peronospora manshurica infection

Soybean downy mildew (SDM) caused by Peronospora manshurica (Pm) is a common disease of soybean that occurs wherever soybean is grown. In order to provide new insights about the defense mechanism of soybean response to Pm infection, differential expression of WRKY transcription factors (TFs) in SDM-high resistant (HR) and SDM-high susceptible (HS) genotypes were analyzed in this study. Totally, 22 WRKY TFs were differentially expressed in HR and HS genotype, while 16 WRKY TFs were found to be specific in response to fungal inoculation. By yeast one-hybrid (Y1H) assay, the GmWRKY31 was characterized to be able to bind the cis-acting W-box element in the promoter region of the GmSAGT1 gene whose higher transcriptional expression was associated with enhanced SDM-resistance. This result of Y1H assay, together with the activation of GmSAGT1 both by SA (salicylic acid) induction and Pm infection in vivo, let us to speculate that the GmWRKY31 might regulate the GmSAGT1 gene expression and involve in SA-mediated immune responses in soybean.

The MAPK Kinase Kinase GmMEKK1 Regulates Cell Death and Defense Responses

MAPK signaling pathways play critical roles in plant immunity. Here, we silenced multiple genes encoding MAPKs using virus-induced gene silencing mediated by Bean pod mottle virus to identify MAPK genes involved in soybean (Glycine max) immunity. Surprisingly, a strong hypersensitive response (HR) cell death was observed when soybean MAPK KINASE KINASE1 (GmMEKK1), a homolog of Arabidopsis (Arabidopsis thaliana) MEKK1, was silenced. The HR was accompanied by the overaccumulation of defense signaling molecules, salicylic acid (SA) and hydrogen peroxide. Genes involved in primary metabolism, translation/transcription, photosynthesis, and growth/development were down-regulated in GmMEKK1-silenced plants, while the expression of defense-related genes was activated. Accordingly, GmMEKK1-silenced plants were more resistant to downy mildew (Peronospora manshurica) and Soybean mosaic virus compared with control plants. Silencing GmMEKK1 reduced the activation of GmMPK6 but enhanced the activation of GmMPK3 in response to flg22 peptide. Unlike Arabidopsis MPK4, GmMPK4 was not activated by either flg22 or SA. Interestingly, transient overexpression of GmMEKK1 in Nicotiana benthamiana also induced HR. Our results indicate that GmMEKK1 plays both positive and negative roles in immunity and appears to differentially activate downstream MPKs by promoting GmMPK6 activation but suppressing GmMPK3 activation in response to flg22. The involvement of GmMPK4 kinase activity in cell death and in flg22- or SA-triggered defense responses in soybean requires further investigation.

Transcriptomic analysis of genes in soybean in response to Peronospora manshurica infection

BackgroundSoybean downy mildew (SDM), caused by Peronospora manshurica (Pm), is a major fungal disease in soybean. To date, little is known regarding the defense mechanism at molecular level and how soybean plants response to Pm infection. In this study, differential gene expression in SDM-resistant (HR) and SDM-susceptible (HS) genotype was analyzed by RNA-seq to identify differentially expressed genes (DEGs) following Pm infection.ResultsOf a total of 55,017 genes mapped to the soybean reference genome sequences, 2581 DEGs were identified. Clustering analysis of DEGs revealed that these genes could be grouped into 8 clusters with distinct expression patterns. Functional annotation based on gene ontology (GO) and KEGG analysis indicated they involved in diverse metabolism pathways. Of particular interest were the detected DEGs participating in SA/ROS and JA signalling transduction and plant/pathogen interaction.ConclusionTotally, 52 DEGs with P value < 0.001 and log2 fold change > 2 or < − 2 upon fungal inoculation were identified, suggesting they were SDM defense responsive genes. These findings have paved way in further functional characterization of candidate genes and subsequently can be used in breeding of elite soybean varieties with better SDM-resistance.

Risk of pathogens associated with plant germplasm imported into India from various countries

During 2012–2014, a total of 309,182 germplasm samples including trial materials were received in the form of seeds, vegetative propagules and in vitro plantlets from different countries. These samples were tested for quarantine clearance resulted in interception of 30 pathogenic fungi and one bacterium in 63 crop species from 35 countries including Peronospora manshurica and Fusarium oxysporum f. sp. cucumerinum (not reported from India); Bipolaris maydis, B. oryzae, Colletotrichum gloeosporioides, C. lindemuthianum, Fusarium solani, F. verticillioides, Puccinia carthami (have different races); Botrytis cinerea, Phoma sorghina, Rhizoctonia solani, Macrophomina phaseolina, Sclerotinia sclerotiorum (have wide host range); Tilletia barclayana (have limited distribution); Alternaria ricini on Tagetes spp., Bipolaris maydis on Capsicum annuum, B. oryzae on Brassica oleracea var. botrytis and Solanum lycopersicum and Colletotrichum capsici on Abelmoschus esculentus (new host record), etc. and Xanthomonas campestris pv. campestris (have different races) which are of quarantine significance to India. Infected samples were salvaged by adopting suitable techniques, however, 636 samples could not be salvaged, hence, rejected and incinerated. Interception of large number of pathogens of quarantine significance on a wide range of crops from different countries emphasizes the need for utmost care and vigilance during quarantine processing of imported plant genetic resources to biosecure India by intercepting the entry of exotic pathogens or more virulent races/strains in the country.

The Pathogens and Lepidopteran Pests on Corn and Soybeans in the Transylvanian Plain

In the climatic conditions in the Transylvanian Plain in corn usually occurs the following diseases and pests: cob rot strains ( Gibberella zeae f.c. Fusarium graminearum ) common smut ( Ustilago maydis ) and rust ( Puccnia sorghi ); Ostrinia nubilalis , Autographa gamma , Agrotis segetum , Agrotis ypsilon , Amathes c-nigrum, Heliothis armigera . In soybeans most common diseases are: bacterial blight ( Pseudomonas glycinea ), midlew ( Peronospora manshurica ) and mold ( Fusarium spp) and of harmful lepidoptera: Autographa gamma , Agrotis segetum , Agrotis ypsilon , Amathes c-nigrum , Mamestra brassicae and Mamestra suas. In the experimental fields of ARDS Turda in corn crop the most frequent disease was FHB and bacterial blight in soybean and the main pests found were the species Autographa gamma and Agrostis segetum.

Influence of infection of soybean seeds with Peronospora manshurica and Pseudomonas syringae pv. glycinea on protein, oil and fatty acids content

The effect of soybean seed infection by &lt;i&gt;Peronospora manshurica&lt;/i&gt; and &lt;i&gt;Pseudomonas syringae&lt;/i&gt; pv. &lt;i&gt;glycinea&lt;/i&gt; on the chemical content of some soybean lines and varieties susceptible to both pathogens was estimated. The amount of protein and oil was determined for soybean seed samples collected from two different localities in 1980. In &lt;i&gt;P. manshurica&lt;/i&gt; oospore-encrusted seeds protein content was higher and oil content lower than in healthy ones. It could be seen especially in samples of the 'Acme' variety cultivated in both localities. Seed infection by &lt;i&gt;P. syringae&lt;/i&gt; pv. &lt;i&gt;glycinea&lt;/i&gt; occasionally influenced the protein, oil and fatty acid content as compared with the control. This was noted only in single cases. Analysis of fatty acid composition demonstrated a higher free fatty acid content in soybean seed infected by &lt;i&gt;P. manshurica&lt;/i&gt;. These results showed undoubtedly the influence of pathogens, specially seed-borne fungi on the chemical soybean seed composition. This analysis can be an introduction for more detailed investigations on the effect of these or other pathogens on soybean seed yield quality.