Common Scab Research Articles

The Influence of Biochar and Substrates Application on the Parameters and Yield of Mini-Tubers of the Charoit Potato Variety

The objects of research were potato meristem plants of the Charoite variety, mass and the number of mini-tubers grown on the “Agrobalt S” peat fertilizer and in a mixture of “ORVI” and biochar substrate in a closed greenhouse. A statistically significant effect of the use of this substrate and biochar on the increase in the number of standard mini-tubers relative to the control variant using only peat soil was established. The yield of standard tubers (9 – 60 mm) was 78 % when using “Agrobalt S” peat soil; 10 % of the substrate "ORVI" and 5 % of biochar, 78 %; 20 % of the substrate “ORVI” and 5 % of biochar, 77 %. A decrease in the standard material of mini-tubers of the Charoite variety against the background of an increase in quantitative indicators does not occur when using the substrate and biochar. Evaluation of latent viral infection of meristem plants and mini-tubers grown from them was performed by ELISA (Sandwich variant) in July and February and did not reveal latent infection in any of the variants. The determination of growing parameters was carried out a month after harvesting and showed that mini-tubers in all variants had no signs of the late blight disease, rhizoctonia disease, common scab, etc.

Breeding of early ripening potato varieties under the conditions of the Kabardino-Balkarian foothill zone

Evolution and thousands of years of artificial selection have contributed to the formation of the widest variety of cultivated potatoes. Thanks to this, more than 4 thousand varieties of potatoes have been created in the world today. All of them are known to differ not only in habit, but also in the level of yield, ripening period, resistance degree to numerous diseases and pests, plasticity to certain climatic and soil conditions. The results of research and evaluation of 4 thousand hybrids of the 1st tuber generation (single-tuberous plants) of joint breeding of the Institute of Agriculture ISKh KBNTs RAN and FSBSI (Federal state budgetary scientific institution) “Federal Research Center (FRC) of Potato name after A.G. Lorkh” that passed the full scheme of breeding tests, 9 promising cross-breed populations with economically useful traits were identified: consistently high yield and resistance to a complex of viral, bacterial and fungal diseases. The selected cross-breeds are distinguished by early and medium early ripening periods with a growing season of 55-70 days and a maximum yield of 38.6-66.2 ton/ha, depending on the prevailing weather conditions during the growing season of potato plants in 2019-2020. The genotypes obtained are involved in the implementation of the federal scientific and technical program for the development of potato growing for 2017-2030. The main goal of the program is to create new varieties of early ripeness group of potatoes. The co-executors of this program are a number of research institutes of the Russian Federation, including the Institute of Agriculture ISKh KBNTs RAN. [1] As a result of many years of investigation, the promising cross-breed 2652-15 that emerged from breeding of the Malinovka variety with the backcross 93.20-12 under the name Zamir was transferred in 2020 for the State test of the Russian Federation in the North Caucasian region. Medium early variety for table use and mashed potatoes processing. Potential yield is 49.5 ton/ha. Tubers of an attractive rounded oval shape with shallow eyes weighing 85.5-108.4 g with a yellow color of the tuber and creamy flesh. The tubers are resistant to mechanical damage during combine harvesting, storability is good. Medium resistant to late blight in tops and highly resistant to tubers. Relatively resistant to rhizoctonia and common scab, banded and wrinkled mosaic of leaves.

BASAL LEVEL OF GENES EXPRESSION OF CINNAMIC ACID METABOLISM ENZYMES IN THE LEAVES OF IN VITRO PLANTS OF POTATOES VARIETIES OF BELARUSIAN BREEDING

The unique gene-specific primers were developed to assess the level of gene expression of cinnamic acid metabolism in potato leaf cells. The basal level of the relative gene expression of tyramine hydroxycynnamoyl transferase (THT) and cinnamate 4-hydroxylase (C4H) was estimated. The presence of correlations between the level of expression of the research genes and potatoes resistance to diseases such as late blight, rhizoctonia,
 common scab, black leg is discussed.

EFFICIENCY OF A NEW PREPARATION BAGRETS PLUS, KS FOR PRE-PLANT TREATMENT OF POTATOES TUBERS

The research results of the biological and economic efficiency of the Bagrets Plus, KS dressing agent in the period 2019–2020 for the pre-planting treatment of seed tubers for the control of Rhizoctonia rot, common scab and Colorado potato beetle are presented.

Inventory of the potato diseases and impact on growth and yield traits in far North Cameroon

Potato (Solanum tuberosum L) production in the Far North Region of Cameroon is faced with scarcity or inequality of rains and with diseases that affect yields. To improve the production a study was conducted in the production area of Mogode subdivision with the objective of identifying potato diseases and pathogens agents. The experimental design was in complete randomized blocks. The plant material used was a local variety of potato (Dosa). Diseases and pathogens have been identified on a base of symptoms and morphological characteristics. The incidence, severity and rainfall were assessed. Yield, number of stems and diameter of the tubers were evaluated. The diseases identified are fungal (late blight, Alternaria or early blight and Fusarium wilt), viral (Virosis M, Rust stain and Potato leaf roll (PLR) and bacterial (Bacterial wilt and Common scab). Conidia of Phytophthora infestans, and Alternaria spp. were found.Whatever the site and disease, the incidence has remained below 25%. Late blight was more present in the Gouria site, Alternaria and virosis M more present in the Mouvou site. The yield was roughly the same at the two sites, around 3 t/ha. The highest number of stems was obtained at Gouria, 18 ± 0.75. The potato is attacked by several diseases. The results of this study represent an important baseline data for the implementation of integrated disease management in Cameroon.Keywords: Solanum tuberosum, diseases, pathogens, incidence, severity, yield.

A Novel Species-Level Group of Streptomyces Exhibits Variation in Phytopathogenicity Despite Conservation of Virulence Loci.

The genus Streptomyces includes several phytopathogenic species that cause common scab, a devastating disease of tuber and root crops, in particular potato. The diversity of species that cause common scab is unknown. Likewise, the genomic context necessary for bacteria to incite common scab symptom development is not fully characterized. Here, we phenotyped and sequenced the genomes of five strains from a poorly studied Streptomyces lineage. These strains form a new species-level group. When genome sequences within just these five strains are compared, there are no polymorphisms of loci implicated in virulence. Each genome contains the pathogenicity island that encodes for the production of thaxtomin A, a phytotoxin necessary for common scab. Yet, not all sequenced strains produced thaxtomin A. Strains varied from nonpathogenic to highly virulent on two hosts. Unexpectedly, one strain that produced thaxtomin A and was pathogenic on radish was not aggressively pathogenic on potato. Therefore, while thaxtomin A biosynthetic genes and production of thaxtomin A are necessary, they are not sufficient for causing common scab of potato. Additionally, results show that even within a species-level group of Streptomyces strains, there can be aggressively pathogenic and nonpathogenic strains despite conservation of virulence genes.

Biocontrol of potato common scab by Brevibacillus laterosporus BL12 is related to the reduction of pathogen and changes in soil bacterial community

Potato common scab (PCS) has caused severe economic losses worldwide. Some biocontrol bacteria have been used for effective control of PCS. It was reported that the occurrence of PCS was related to soil microbial community. However, it is still unclear whether soil microbes participate in the disease control by biocontrol agent. Here, Brevibacillus laterosporus BL12 that antagonized PCS pathogen is reported to suppress PCS by reducing pathogen abundance and regulating soil bacterial community. The results of quantitative PCR and high-throughput sequencing demonstrated that the biocontrol strain BL12 stably colonized the tuberosphere soil and rhizosphere soil, and became a keystone species in the bacterial community network of the tuberosphere soil. The application of biocontrol strain BL12 significantly changed the composition and function of bacterial communities in the tuberosphere soil and rhizosphere soil. Some putative beneficial bacteria related to plant disease control such as Pseudomonas and Microbacterium were significantly positively correlated with biocontrol strain BL12, and significantly negatively related to the disease index and/or pathogen. They may cooperate with biocontrol strain BL12 to control PCS. Functional prediction showed that the application of biocontrol strain BL12 significantly increased the relative abundance of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways such as biosynthesis of macrolides, biosynthesis of ansamycins, and biosynthesis of siderophore group nonribosomal peptides, and significantly reduced the relative abundance of nitrogen metabolism and bacterial secretion system. This research provided potential micro-ecological mechanisms for controlling plant diseases with biocontrol agent.

Waneta, a Variety with Excellent Chip Color out of Cold Storage, Long Tuber Dormancy, and Resistance to the Golden Cyst Nematode

Waneta is a white-skinned, white-fleshed potato variety notable for excellent chip color from cold storage, good yield, long tuber dormancy, and resistance to both common scab and race Ro1 of the golden cyst nematode (Globodera rostochiensis). It was selected from a cross made at Cornell University in 1998 between Marcy and NY115. The tubers are round to oblong with shallow eyes and relatively smooth skin. Chip color out of cold storage is lighter than ‘Snowden’. Marketable yield averaged 91% of Snowden across 88 trials in New York, Pennsylvania and Maine, while specific gravity averaged 0.010 less than Snowden. Waneta was released by the New York Agricultural Experiment Station in 2011.

The Efficacy of the Turmax Drug for Cultivating Potatoes under the Conditions of the Tomsk Oblast

The paper presents the results from field trials of Turmax organomineral supplements. The goal of the study was to investigate the effect of this drug on increasing potato yields and reducing the incidence of potato diseases. The object was the Turmax drug, which includes the basic mineral nutrients and metabolic products of rhizospheric microorganisms. The tests were carried out with the cultivation of Nevsky potatoes for 4 years with different weather conditions on gray forest soil. Test options included control, a single spraying of potato plants by Turmax on seedlings and in the budding phase, and two-time spraying of plants on seedlings and in the budding phase. The results of the study showed that double processing of potatoes was the most effective in different weather conditions—for seedlings and before flowering. Potato yield increased by 21–40% in different years. This treatment not only significantly increased the potato yield but also decreased the incidence of their fungal (late blight, rhizoctonia, common scab) and bacterial (bacterial rot, wet rot, ring rot) infections.

Assessment of technological gap and performance of management of common scab of potato

Common scab (Streptomyces scabies) disease of potato is becoming prominent in many potato-growing districts of Rajasthan resulting in economic losses, since a decade. The experiment was executed out to assess the technological gap and performance of management approaches. Potato tubers of cultivar Kufri Bahar was treated with 3.0 per cent boric acid before planting (spray) for the duration of time 30 min and evaluated against the pathogen. This experiment was conducted as on farm trials (OFT) at different villages likewise Phoospura, Naurangabad, Moosalpur, Saktpur and Sarkankhera in Dholpur district for two years (2017-18 to 2018-19). As a result of this experiment treated tuber plants registered the lowest disease incidence (10.6%) and disease control (75.05) as compared to existing farmer practices (FP). The adoption of demonstrated technology was improved potato production and plant protection measures. The OFT was effective in changing the attitude, skill and knowledge of plant protection approach. Potato yield also increased upto 10.37 per cent as compared to the existing FP. Results indicates that plant protection approach increased the net income by Rs. 80580/- ha over the existing FP. It is suggested to organize demonstrations at farmers field on technology assessed through OFT by agriculture department for minimizing the technological gap and increased yield of quality potato.

Functional Cross-Talk of MbtH-Like Proteins During Thaxtomin Biosynthesis in the Potato Common Scab Pathogen Streptomyces scabiei.

Thaxtomin A is a potent phytotoxin that serves as the principle pathogenicity determinant of the common scab pathogen, Streptomyces scabiei, and is also a promising natural herbicide for agricultural applications. The biosynthesis of thaxtomin A involves the non-ribosomal peptide synthetases (NRPSs) TxtA and TxtB, and an MbtH-like protein (MLP), TxtH, which may function as a chaperone by promoting the proper folding of the two NRPS enzymes in S. scabiei. MLPs are required for the proper function of many NRPS enzymes in bacteria, and they are often capable of interacting with NRPSs from different biosynthetic pathways, though the mechanism by which this occurs is still poorly understood. To gain additional insights into MLP functional cross-talk, we conducted a broad survey of MLPs from diverse phylogenetic lineages to determine if they could functionally replace TxtH. The MLPs were assessed using a protein solubility assay to determine whether they could promote the soluble expression of the TxtA and TxtB adenylation domains. In addition, the MLPs were tested for their ability to restore thaxtomin production in a S. scabiei mutant that lacked TxtH and other endogenous MLPs. Our results showed that the MLPs investigated vary in their ability to exhibit functional cross-talk with TxtH, with two of the MLPs being unable to compensate for the loss of TxtH in the assays performed. The ability of an MLP to serve as a functional partner for the thaxtomin NRPS was not correlated with its overall amino acid similarity with TxtH, but instead with the presence of highly conserved residues. In silico structural analysis of TxtH in association with the TxtA and TxtB adenylation domains revealed that several such residues are situated at the predicted interaction interface, suggesting that they might be critical for promoting functional interactions between MLPs and the thaxtomin NRPS enzymes. Overall, our study provides additional insights into the mechanism of MLP cross-talk, and it enhances our understanding of the thaxtomin biosynthetic machinery. It is anticipated that our findings will have useful applications for both the control of common scab disease and the commercial production of thaxtomin A for agricultural use.

Investigation of Streptomyces scabies Causing Potato Scab by Various Detection Techniques, Its Pathogenicity and Determination of Host-Disease Resistance in Potato Germplasm.

Streptomyces scabies is a Gram-positive bacterial pathogen that causes common scab disease to several crops, particularly in the potato. It is a soil borne pathogen, a very devastating scab pathogen and difficult to manage in the field. Streptomyces has several species that cause common scab such as S. scabiei, S. acidiscabies, S. europaeiscabiei, S. luridiscabiei, S. niveiscabiei, S. puniciscabiei, S. reticuliscabiei, S. stelliscabiei, S. turgidiscabies, S. ipomoeae. Common scab disease harmfully affects potato economic and market value due to the presence of black spots on the tuber. Owing to its genetic diversity and pathogenicity, the determination of pathogen presence in potato fields is still challenging. In this study, S. scabies genetic diversity was measured by surveying five potato-growing areas of Pakistan during the growing season 2019. A total of 50 Streptomyces isolates, including S. scabies, S. acidiscabies, S. griseoflavus were isolated and identified based on morphologic, biochemical and molecular analysis. Virulent confirmation assays confirmed ten virulent strains of Streptomyces spp. On the potato cultivars Cardinal and Santee. Among the Streptomyces species, S. scabies showed the highest scab index, followed by S. acidiscabies and S. griseoflavus by exhibiting the scab-like lesions on potato tubers. Ten potato cultivars were screened against these virulent isolates of Streptomyces. The Faisalabad white variety showed the highest scab index followed By Cardinal, Tourag, Kuroda, Santee, Lady Rosetta, Asterix, Diamant, Faisalabad red and Sadaf. Moreover, genetic diversity and pathogenicity of Streptomyces spp. on potato tubers were also likely diverse in different geographical regions and also potato cultivars. This study represents a contribution to understanding the local interaction between potatoes and Streptomyces spp. in Pakistan. It will aid in supporting a solution for the management of this pathogen around the world.

Genome-Wide Association Analysis of Common Scab Resistance and Expression Profiling of Tubers in Response to Thaxtomin A Treatment Underscore the Complexity of Common Scab Resistance in Tetraploid Potato

Common scab of potato caused by pathogenic Streptomyces species poses an economic burden to commercial potato cultivation. Despite decades of research, no molecular markers linked to this trait are currently available, making the development of scab resistant potato varieties inefficient. We evaluated common scab lesion type and tuber coverage in 198 individuals segregating for common scab resistance in replicated field trials with high natural disease pressure over two growing seasons. To identify genetic features associated with resistance, we genotyped the tetraploid (4x) population and parental lines (Kalkaska and Tundra) using the Illumina Infinium 8303 Potato Array and conducted genome-wide association analysis. Here, we report two significant single nucleotide polymorphism (SNP) markers on chromosome 1 associated with both scab traits in both years as well as a SNP marker on chromosome 2 associated with scab tuber coverage. Gene expression profiling of the parents of this population in response to Thaxtomin A treatment revealed differential expression of genes in tubers putatively involved in cell wall biosynthesis and hormone signaling.

The degradation fragments of gamma-glutamyl transpeptidase from Bacillus subtilis BU108 have antimicrobial activity against Streptomyces scabiei

Bacillus species are often regarded as ideal biocontrol agents against plant pathogens, which can produce various antimicrobial peptides (AMPs). In this study, strain BU108 with good antimicrobial activity against Streptomyces scabiei was isolated from the rhizosphere soil of a potato field, which was then identified as Bacillus subtilis through 16S rDNA sequence analysis. An antimicrobial protein was purified by ammonium sulfate precipitation, ion exchange chromatography and ultrafiltration. The active sample showed a single band on SDS-PAGE gel, which was identified by mass spectrometry as partial fragments of gamma-glutamyl transpeptidase (GGT). To verify this new finding, three potential AMPs (KT20, IF20 and AE26) were predicted based on the sequence and structure of GGT, and the antimicrobial activity test confirmed two AMPs (KT20 and IF20). As GGT was involved in the metabolism of glutathione in former references, in this study, we reported the antimicrobial activity of its degradation fragments for the first time, which not only enriched the antimicrobial substance of Bacillus subtilis, but also provided a new choice for potato common scab biocontrol.

The distribution and economic losses from common scab of sheep in the Republic of Dagestan

The distribution and economic losses from common scab of sheep in the Republic of Dagestan

Prevention of common scab of sheep in the Republic of Dagestan with the use of acaricidal remedies Botox

Prevention of common scab of sheep in the Republic of Dagestan with the use of acaricidal remedies Botox

Assessing the suppressive effects of biopesticides and phosphite on common scab development in potatoes

ABSTRACT Potato common scab (CS) is caused by several saprophytic bacteria of the genus Streptomyces, including Streptomyces scabies. Various methods have been investigated to control CS, but their efficiency is usually low. Biopesticide formulations, including bacteria from the Bacillus spp., are increasingly used to control soil pathogens. Two Bacillus-based products, Double Nickel 55TM and Microflora PROTM, and the phosphite-based fungicide PhostrolTM, alone or in combination, were examined to determine their effects on CS development on tubers of the potato cultivars Red Pontiac, Prospect, Green Mountain, and Goldrush. CS disease incidence and severity were assessed using 4 parameters: percentage of tuber area covered by CS, necrotic areas, the number of deep pits and of shallow pits. The effects of treatments on tuber periderm morphology were assessed by determining the number of suberised cell layers and the thickness of suberised cell layers. Cultivar Goldrush performed much better than the other three cultivars, in all parameters scored. Among the six treatments, only Double Nickel 55TM + PhostrolTM reduced CS more consistently. Suberised cell size, shape, arrangement, number of layers, and phellem thickness, were found to vary largely across cultivars. A thicker phellem, but not the number of cells in the phellem, was found to be associated with improved resistance to CS. Treatments had limited effect on the number of layers of suberised cells and phellem thickness and these effects seemed to be cultivar specific. Overall, Double Nickel 55TM and Microflora PROTM were found to augment the number of suberised cell layers.

The study of a new potato variety Vychegodsky according to a set of economically valuable traits

In the conditions of the Komi Republic in 2017-2019 a comprehensive assessment of the new medium early tablevariety of potato Vychegodsky was carried out. Two zoned and one recommended for the I Northern region of the RussianFederation potato varieties were used as standard. They had different periods of ripening and various parameters of responsiveness to environmental conditions (linear regression coefficient of the yield of varieties bi). The varieties were Udacha(recommended) - early, poorly responsive (bi = 0.5), Nevsky (zoned) – medium early, with close to linear dependence (bi = 1.0)and the variety of local selection Zyryanets (zoned) - medium early, with the highest response coefficient (bi = 1.7). In 2017,the significant excess by 7.0 t/ha of the yield of tubers of the Vychegodsky variety over the Nevsky standard was determined.On average for three years of research the productivity of the new variety was 27.2 t/ha (1.7-2.0 t/ha higher than the controls).The yield of Vychegodsky variety was formed mainly during the last 20 days of vegetation, and the average weight of a tuberhad increased by 134% during that period. On the whole, Vychegodsky variety formed 10-12 tubers weighing 40-60 g.The plasticity of the variety is moderate (bi = 1.2), which is optimal for a risk farming zone. The dry matter content is 24.1%,starch is 15.7%, and vitamin C is 11.2 mg%. Vychegodsky variety has demonstrated high resistance to major diseases affectingthe tops and tubers during the summer vegetation period (late blight, altarnariosis, rhizoctoniosis, common scab). A moleculargenetic expert study of DNA for the presence of 10 major resistance marker genes has been conducted. Genes responsiblefor the resistance of the Vychegodsky variety to potato cancer and golden potato nematode have been revealed.

Unsupervised adversarial deep domain adaptation method for potato defects classification

In the last few years, deep learning methods have been proposed to automate the quality control of various agricultural products. Despite the excellent results obtained, one of their main drawbacks is the need for a large annotated dataset to obtain satisfactory performance. Building this dataset is time-consuming and tedious. Moreover, in some real-world applications, vision systems can be modified over time. Such changes may generate a drop in network performance trained with the initial database (source images). To avoid the creation of a new labeled database every time a change in data distribution occurs (target images), several domain adaptation methods have been proposed. In this article, we introduce an unsupervised deep domain adaptation method based on adversarial training. A large dataset is used, including six classes of potatoes: healthy, damaged, greening, black dot, common scab, and black scurf. Two different scenarios of domain adaptation problem are considered. Firstly, a simply modification of the image acquisition system is simulated by artificially increasing the brightness of some white potatoes images (target images). Secondly, a significantly different dataset including red potatoes is introduced. In this setting, white potatoes are used as source images and red tubers as target images. We propose to train a target classifier using a pseudo-label loss, due to the unavailability of target annotations. Experimental results show that a domain adaptation method is mandatory, going from an average F1-score of 0.46 without adaptation, to 0.84 by applying our method. Finally, a comparative analysis is achieved showing that adversarial-based unsupervised domain adaptation methods outperform discrepancy-based approaches.

A Novel Streptomyces sp. Strain PBSH9 for Controlling Potato Common Scab Caused by Streptomyces galilaeus.

Potato common scab is an important soilborne disease worldwide that can significantly reduce the quality and economic values of potato. The disease is caused by multiple species of Streptomyces, which are not well controlled due to lack of effective strategies. Streptomyces galilaeus has been recently identified as a dominant species causing potato common scab in Inner Mongolia, China. This study was focused on screening and characterizing antagonists for biological control against pathogenic S. galilaeus. Bacterial strain PBSH9 was isolated from a potato tuber. PBSH9 was identified as a Streptomyces sp. on the basis of morphological, physiological, and biochemical characteristics, as well as DNA sequence analysis. PBSH9 inhibited S. galilaeus with a diameter of inhibitory zone of 19.8 mm on agar plates. The extracellular filtrate of PBSH9 also inhibited S. galilaeus growth with a diameter of inhibition zone of 10.0 mm. Furthermore, PBSH9 promoted potato sprouting and emergence. Disease control was up to 81.88% in greenhouse trials, and from 47.64 to 73.97% in 3-year field trials. Among the tested inoculation methods, seed treatment was more effective than soil drenching for PBSH9 application. PBSH9 not only effectively controlled potato common scab but also increased potato growth. Thus, it can be a potential candidate for biocontrol agent.