Control Efficacy of Bacillus velezensis AFB2-2 against Potato Late Blight Caused by Phytophthora infestans in Organic Potato Cultivation

Although late blight is an important disease in eco-friendly potato cultivation in Korea, it is highly dependent on the use of eco-friendly agricultural materials and the development of biological control technology is low. It is a necessary to develop an effective biocontrol agent to inactivate late blight in the field. AFB2-2 strain is a gram-positive with peritrichous flagella. It can utilize 20 types of carbon sources, like L-arabinose, and D-trehalose at 35°C. The optimal growth temperature of the strain is 37°C. It can survive at 20-50°C in tryptic soy broth. The maximum salt concentration tolerated by AFB2-2 strain is 7.5% NaCl. AFB2-2 strain inhibited the mycelial growth of seven plant pathogens by an average inhibitory zone of 10.2 mm or more. Among the concentrations of AFB2-2, 107 cfu/ml showed the highest control value of 85.7% in the greenhouse. Among the three concentrations of AFB2-2, the disease incidence and severity of potato late blight at 107 cfu/ml was lowest at 0.07 and 6.7, respectively. The nucleotide sequences of AFB2-2 strain were searched in the NCBI GenBank; Bacillus siamensis strain KCTC 13613, Bacillus velezensis strain CR-502, and Bacillus amyloliquefaciens strain DSM7 were found to have a genetic similarity of 99.7%, 99.7%, and 99.5%, respectively. The AFB2-2 strain was found to harbor the biosynthetic genes for bacillomycin D, iturin, and surfactin. Obtained data recommended that the B. velezensis AFB2-2 strain could be considered as a promising biocontrol agent for P. infestans in the field.

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Antagonistic activity of Bacillus velezensis SDTB038 against Phytophthora infestans in potato

Plant Disease ◽

10.1094/pdis-08-20-1666-re ◽

2020 ◽

Author(s):

Haohao Yan ◽

Yue Qiu ◽

Shuai Yang ◽

Yongqiang Wang ◽

Kaiyun Wang ◽

...

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Chemical Properties ◽

Good Control ◽

Potato Late Blight ◽

Field Trials ◽

Bacillus Velezensis ◽

High Concentration ◽

Control Effect ◽

Epidemic Disease

Potato late blight is a severe and highly epidemic disease caused by Phytophthora infestans that can affect all parts of the plant. This study mainly screened antagonistic strains for good control of potato late blight and identified strain SDTB038 as Bacillus velezensis according to its morphological and chemical properties and the 16S rRNA, gyrA and gyrB gene sequences. This antagonistic strain achieved good control of potato late blight in greenhouses and fields and promoted potato plant growth. Two-year field trials (2018, 2019) showed that B. velezensis SDTB038 can be used to reduce food losses caused by late blight, achieving late blight reductions of 40.79% (2018) and 37.67% (2019). In two-year field trials, the control effects of the highest concentrations of fluopimomide and B. velezensis SDTB038 were better than those of the other treatments. The control effect of 85 g ha-1 fluopimomide and B. velezensis SDTB038 and that of 170 g ha-1 fluopimomide alone showed no significant differences. These field results indicate that a low concentration of fungicide and a high concentration of SDTB038 can be effective in controlling potato late blight. Foliar detection showed that lipopeptides (LPs) have an inhibitory effect on P. infestans. The amplification of LP genes revealed surfactin (srfAB, srfAC) and fengycin (fenB) genes in SDTB038, but only surfactin production by B. velezensis SDTB038 was observed by UPLC-Q-TOF-MS analysis. Therefore, the strain B. velezensis SDTB038 can produce secondary metabolites that help potato plants resist late blight development, can effectively inhibit the infection of potato leaves by P. infestans, and has potential value for development as a biological pesticide against potato late blight.

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Complete genome sequence of Bacillus velezensis M75, a biocontrol agent against fungal plant pathogens, isolated from cotton waste

Journal of Biotechnology ◽

10.1016/j.jbiotec.2016.11.023 ◽

2017 ◽

Vol 241 ◽

pp. 112-115 ◽

Cited By ~ 24

Author(s):

Sang Yoon Kim ◽

Sang Yeob Lee ◽

Hang-Yeon Weon ◽

Mee Kyung Sang ◽

Jaekyeong Song

Keyword(s):

Genome Sequence ◽

Complete Genome Sequence ◽

Complete Genome ◽

Plant Pathogens ◽

Biocontrol Agent ◽

Bacillus Velezensis ◽

Fungal Plant Pathogens ◽

Cotton Waste

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Pathogens which threaten food security: Phytophthora infestans, the potato late blight pathogen

Food Security ◽

10.1007/s12571-021-01141-3 ◽

2021 ◽

Author(s):

Jonathan Yuen

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Large Scale ◽

Plant Disease ◽

Plant Pathogens ◽

Potato Production ◽

Potato Late Blight ◽

Developed Countries ◽

History Of ◽

Late Blight Pathogen

AbstractPotato late blight, caused by Phytophthora infestans, is a critical disease of potato and other solanaceous crops, such as tomato. The history of late blight is, in some ways, the history of modern plant pathology. It received much attention in the mid 1800’s by causing the Irish potato famine, and the pathogen played a prominent role in the development of the concept of plant disease and plant pathogens. The pathosystem has also been important in the development of pesticides that are active against plant pathogens, and has also been a model system in understanding concepts ranging from cellular processes, such as how resistance to plant pathogens functions, to large scale processes, such as implementation of regional plant disease warning systems. P.infestans has a secured a place in modern potato production, both in developed and less-developed countries.

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Masa Inkubasi Gejala Penyakit Hawar Daun Tanaman Kentang yang Diinduksi Ketahanannya oleh Jamur Antagonis Trichoderma viride

Bioma Berkala Ilmiah Biologi ◽

10.14710/bioma.18.2.41-47 ◽

2016 ◽

Vol 18 (2) ◽

pp. 41

Author(s):

Susiana Purwantisari ◽

Achmadi Priyatmojo ◽

Retno Peni Sancayaningsih ◽

Rina Sri Kasiamdari

Keyword(s):

Late Blight ◽

Phytophthora Infestans ◽

Disease Incidence ◽

Trichoderma Viride ◽

Potato Late Blight ◽

Biocontrol Agents ◽

Trichoderma Spp ◽

Late Blight Disease ◽

Blight Disease

Late blight disease caused by Phytophthora infestans, is probably the single most important disease of potatoes worldwide. Infected plants were quickly killed and were difficult for replanting, causing significant losses for the growers. Various control methods were examined including the use of biocontrol agents of Trichoderma spp. The biocontrol potential of Trichoderma viride against potato late blight pathogen, Phytophthora infestans, were studied under greenhouse conditions. The research objective was to determine the ability of biocontrol agents Trichoderma viride to delay late blight disease incidence on potato plants in the field. The in vivo experiment was carried out at potato land area located at BALITSA in Cikole Sub District, Lembang District and Bandung Regency. Completely Randomized Design was used with six treatment and five replicates. The treatment tested consist of control (without pathogen fungal and antagonists fungus application too), control (with pathogen fungal application and without antagonist fungal application), chemical fungicide application, antagonist fungal application 2 weeks before planting, application 1 week after planting and both application 2 weeks before and 1 week after planting. Result of the research showed that application of antagonists fungal could delay disease intensity until 14 days. These antagonist could be used as biological agents initials to control leaf blight disease. Key words: Biological control, Potato late blight, Phytophthora infestans, Trichoderma viride

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Phytophthora infestans Populations in Latvia

Proceedings of the Latvian Academy of Sciences Section B Natural Exact and Applied Sciences ◽

10.2478/v10046-009-0004-y ◽

2008 ◽

Vol 62 (6) ◽

pp. 223-226 ◽

Cited By ~ 1

Author(s):

Gunita Bimšteine

Keyword(s):

Late Blight ◽

Disease Control ◽

Laboratory Experiment ◽

Phytophthora Infestans ◽

Disease Severity ◽

Plant Pathogens ◽

Certified Seed ◽

Growing Season ◽

Potato Late Blight ◽

The World

Phytophthora infestans Populations in Latvia Potato late blight caused by Phytophthora infestans (Mont.) de Bary is one of the most investigated plant pathogens. However, problems with disease control have increased in recent years, which plant pathologists have explained by its ability of forming oospores in potato leaves. Consequently, the P. infestans population over the world has become more aggressive and virulent and late blight on potato stems is common. Oospores could be found in field conditions in potato leaflets with two or more separate spots. In Latvia the P. infestans mating type A2 was found in the 1980s. A laboratory experiment on the formation of oospores in Latvia was started in 2002. The total number of collected samples was 215. The samples were collected from potato trial fields, conventional fields and from private gardens in different regions of Latvia. Many potato leaflets with two spots were observed at the end of the growing season when the disease severity exceeded 50%. The results showed that the formation of oospores on potato leaflets in the field took place in the P. infestans population in Latvia. Oospores were found in 80-94% of the investigated cases. The occurrence of oospores means that plant rotation and certified seed material are important measures for potato late blight control and the usage of fungicides may not be effective.

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MANAGEMENT OF POTATO LATE BLIGHT THROUGH HOST PLANT RESISTANCE AND FUNGICIDE USE IN SOUTH OMO ZONE, SNNPR, ETHIOPIA

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v5.i5.2017.1866 ◽

2017 ◽

Vol 5 (5) ◽

pp. 342-348

Author(s):

Misgana Mitiku ◽

Yesuf Eshete

Keyword(s):

Late Blight ◽

Potato Variety ◽

Disease Incidence ◽

Late Blight Resistance ◽

Potato Late Blight ◽

Total Weight ◽

Local Variety ◽

Significant Difference ◽

South Omo ◽

Blight Disease

The study was carried out in April 2015 at South Ari district, Senmamer kebele of South Omo Zone Southern Nation Nationality People Regional State to test and demonstrate the effects of integrating host resistance and fungicide application for management of potato late blight disease. In this experiment one relatively late blight resistance improved Irish potato variety (Belete) was collected from Holleta Seed producer Association and susceptible local control potato varieties were used. RCBD with four replications (farmers as replication) were used. A recommended rate of CurzateR R WP fungicide was applied while susceptible local variety developed the first blight symptom. GLM procedures were followed to analyze yield, disease incidence and severity. LSD (P<0.01) values were used to separate treatments mean. Total weight of tubers per plot (kg) was show significant difference (P<0.01) among treatments. The highest total weight of tubers per plot (kg) was given by treated belete (T1) (22.625) followed by untreated belete (T3), untreated local (T4) and treated local (T2) (18.525, 11.875and 10.125) respectively (Table 2). Local potato variety also gave the highest unmarketable tubers weight per plot. The result indicated that there were a significant difference (P<0.01) and (P<0.05) among treatments on late blight incidence and severity respectively. Untreated local variety (T4) showed highest late blight incidence and severity as compare to treated belete variety (T1). The experiment result suggested that application CurzateR R WP fungicide twice on variety belete results in significant reduction on late blight progress, with a corresponding increased tubers yield.

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