Potato Wilt Research Articles

Efficacy of Fungicides and Plant Extracts against Fusarium oxysporum f. sp. batatas Incitant of Fusarium Wilt of Sweet Potato (Ipomeae batatas L.)

In vitro experiments were conducted to evaluate the effect of some fungicides and some plant extracts against Fusarium oxysporum f. sp. batatas (Fob). The experiments were conducted in the Plant Pathology Laboratory of the Department of Crop Protection, Bayero University Kano. Three fungicides (Mancozeb, Hexaconazole and Metalaxyl + coprous oxide) and sterile distilled water as control were arranged in a completely randomized design. The treatments were repeated five times. Mancozeb as the most promising fungicide against the fungus was used as a check, other treatments include; 25% aqueous neem leaf extract, 50% aqueous neem leaf extract, 25% aqueous garlic bulb extract, 50% aqueous garlic bulb extract, 25% aqueous callotropis leaf extract, 50% callotropis leaf extract and control. The treatments were arranged in a completely randomized design and repeated thrice. Data on radial growth and percent growth inhibition of the fungus were recorded and subjected to analysis of variance using GenStat 17th Edition. Among the fungicides tested against Fob, Mancozeb significantly had the least radial growth (13mm) and inhibited growth of the pathogen by 71.1% compared to the other fungicides. Bioassay on plant extracts revealed least radial growth of the fungus (36.7mm) and highest percent growth inhibition (43.5%) when 50% aqueous neem leaf extract was used. This differed significantly with the use of 25% aqueous neem leaf extract which caused 39.3 mm radial growth of the fungus and inhibited growth by 38.5%. This was followed by 50% and 25% callotropis leaf extract, respectively with lower fungal growth and higher percent growth inhibition compared to aqueous garlic bulb extract at the different concentrations, exhibiting similar effect on the growth of the fungus and its inhibition. Aqueous neem leaf extract (50%) contained higher phytochemicals than the other botanical extracts at the different concentrations. These phytochemicals are responsible for better suppression of Fob. Application of 50% aqueous neem leaf extract could be further evaluated as potential bio-pesticide to supplement the use of fungicide against Fusarium wilt of sweet potato.

Causes of dangerous fungal diseases of potatoes in the western region of Ukraine due to climate change

Goal. To determine the species composition of pathogens of potato fungal diseases in the western region of the forest-steppe zone under climatic changes.
 Methods. Research was conducted during 2021—2022 on the basis of the Ukrainian Plant Quarantine Research Station of the Institute of Plant Protection using laboratory (identification of pathogens) and field (examination of potato plantations and analysis of tuber material) methods.
 Results. According to the research results, the most common fungal diseases on vegetative plants during the studied period were: anthracnose (Colletotrichum coccodes (Wallr.) S. Hughes), Alternaria solani (Ellis & G. Martin) L.R. Jones & Grout, Alternaria alternata (Fr.) Keissl.), fusarium wilt (Fusarium oxysporum Sсhl.) and late blight (Phytophthora infestans (Mont.) de Bary). As a result of phytopathological analysis of tubers, it was established that the greatest danger during potato storage is caused by pathogens of the genera Fusarium, Phoma, Colletotrichum, Phytophthora, causing fusarium, fomosis, anthracnose, phytophthora and mixed types of rot. the causative agents of fusarium were identified — Fusarium oxysporum Sсhl., F. sambucinum Fuck., F. solani Vart.; phomoza — Rhoma exigua Desm. var. exigua rhizoctonia — Rhizoctonia solani (J. G. Kühn) [teleomorph Thanatephorus cucumeris (A. B. Frank) Donk]; Alternaria solani (Ellis & G. Martin) L.R. Jones & Grout; Alternaria alternata (Fr.) Keissl.; anthracnose — Colletotrichum coccodes (Wallr.) S. Hughes, late blight — Phytophthora infestans (Mont.) de Bary); the share of fusarium was 42.1%, the causative agent of anthracnose — 27.5%.
 Conclusions. Fungal diseases (anthracnose, fusarium wilt) of potatoes, which at the end of the twentieth century were considered to be of limited distribution, have become widespread, which requires their further study in order to optimize crop protection.

Screening for Resistance Resources against Bacterial Wilt in Wild Potato.

Potato is an important crop, used not only for food production but also for various industrial applications. With the introduction of the potato as a staple food strategy, the potato industry in China has grown rapidly. However, issues related to bacterial wilt, exacerbated by factors such as seed potato transportation and continuous cropping, have become increasingly severe in the primary potato cultivation regions of China, leading to significant economic losses. The extensive genetic diversity of Ralstonia solanacearum (R. solanacearum), which is the pathogen of bacterial wilt, has led to a lack of highly resistant potato genetic resources. There is a need to identify and cultivate potato varieties with enhanced resistance to reduce the adverse impact of this disease on the industry. We screened 55 accessions of nine different wild potato species against the bacterial wilt pathogen R. solanacearum PO2-1, which was isolated from native potato plants and belongs to phylotype II. Three accessions of two species (ACL24-2, PNT880-3, and PNT204-23) were identified with high resistance phenotypes to the tested strains. We found these accessions also showed high resistance to different phylotype strains. Among them, only PNT880-3 was capable of flowering and possessed viable pollen, and it was diploid. Consistent with the high resistance, decreased growth of R. solanacearum was detected in PNT880-3. All these findings in our study reveal that the wild potato PNT880-3 was a valuable resistance source to bacterial wilt with breeding potential.

Races and Biovar Characterization of Ralstonia solanacearum Causing Bacterial Wilt Disease of Potato

Ralstonia solanacearum, the causative agent of brown rot/bacterial wilt, is a major cause of severe potato illnesses in many impoverished nations located in tropical and subtropical regions of the world. When it occurs, the disease is to blame for significant losses to the potato industry. The illness has the potential to completely destroy a crop and stop using a piece of land for potato cultivation for a number of years. A survey was carried out to investigate the extent of Ralstonia solanacearum-caused bacterial wilt of potato crops in important potato-growing talukas in the Banaskantha district of Gujarat, India, including Deesa, Dantiwada, Palanpur, and Amirgadh. The frequency of bacterial wilt disease in potatoes is rather low in this region. Four talukas were utilised to identify ten isolates (RsSt1 to RsSt10) of R. solanacearum, which were then used to determine the biovar and race. Gram-negative rod-shaped cells were present in the isolates of R. solanacearum. On TZC agar medium, these isolates developed colonies that were creamy or dull white in colour with a hint of pink or red in the centre. The oxidation of disaccharides (sucrose, lactose, maltose) and sugar alcohols (manitol, sorbitol, and dulcitol) by R. solanacearum isolates was used to determine the biovar characteristics. This revealed that, of the ten isolates, eight were classified as bv2, and the two remaining isolates (RsSt5 and RsSt7) belonged to bv2T. The pathogenicity test conducted on tobacco, tomato, and brinjal allowed for the race identification of R. solanacearum isolates, which were classified as race 3 due to their limited host range and ability to exclusively elicit wilt symptoms in potatoes and tomatoes. As a result, Races 3 and bv2 and bv2T were represented among the R. solanacearum isolates that caused bacterial wilt of potatoes in the Banaskantha district.

Effect of intercropping on potato bacterial wilt disease and tuber yield in Kenya

Potato (Solanum tuberosum L.) is a major tuber crop in Kenya, whose productivity is heavily impaired by bacterial wilt disease, caused by Ralstonia solanacearum (Smith). Existing management strategies have not been effective, owing to the diversity and robustness of the pathogen and variation in the host range. The objective of this study was to evaluate the effectiveness of intercropping on the incidence of bacterial wilt and yield of potato in Kenya. A field experiment was conducted in four potato-growing counties, namely; Nyandarua, Nakuru, Bomet and Bungoma in Kenya. Treatments included intercroping with spring onion (Allium fistulosum L.); garden pea (Pisum sativum L.); and cabbage (Brassica oleracea var. capitata L.). Treatments also included a pure stand of potato as the control. Generally, intercropping had a significant suppressive effect (P<0.05) on the incidence and severity of bacterial wilt disease. Intercropping potato with spring onion, in particular, had the highest disease suppressive effect, followed by intercropping potato with cabbage; and lastly by potato with garden pea. Accordingly, potato-onion intercrop recorded the highest potato tuber yield (12.9 t ha-1), while the potato pure stand recorded the lowest tuber yield (7.9 t ha-1). Bacterial wilt disease incidence positively correlated with disease severity (r = 0.931; P<0.05). In contrast, the disease incidence and severity negatively correlated with tuber yield. In terms of Land Equivalent Ratio (LER), the highest value (1.64) was with potato-onion intercrop; and the lowest (1.35) with the potato-garden pea intercrop.

Culture-based Determination of Verticillium Densities in Soil Overestimates Disease Pressure of Verticillium Wilt of Potato in Manitoba

Verticillium wilt affects potato fields in Manitoba where 80% of the fields are planted to the moderately susceptible cultivar, Russet Burbank. An accurate determination of Verticillium dahliae inoculum in soil is critical for disease management. In this study, we investigated the presence of microsclerotia-producing Verticillium species in potato fields in Manitoba and compared published quantitative real-time PCR assays for V. dahliae, V. tricorpus and V. longisporum against a traditional plating method. Selected real-time PCR assays could differentiate and quantify the major microsclerotia-producing species, V. dahliae, V. tricorpus and V. longisporum. Results showed that the presence of V. tricorpus caused an overestimation of V. dahliae propagule density when using the plating method. As a result, Verticillium wilt severity was negatively related to cfu from traditional plating, while positive with the amounts of V. dahliae genomic DNA in soils.

A Comprehensive Assessment of Verticillium Wilt of Potato: Present Status and Future Prospective

The fungal disease Verticillium wilt is a soil-borne pathogen that is caused by Verticillium dahliae. This disease affects a wide range of crops and can cause significant yield losses. Recent findings suggest that Verticillium wilt has been affecting potato crops in abundant domains around the global world, including in North America, parts of Europe, and Asia. In some cases, the disease has been observed in fields where it has not been previously reported, indicating that it has been spreading. Farmers and researchers are working to manage the disease through a variety of measures, including rotation of crops, the use of resistant varieties of potato developed from resistant strains, and the application of fungicides. However, the potency of these measures can vary depending on the ferocity of the disease and the local growing circumstances. Overall, the recent findings of Verticillium wilt in potato underscore the importance of continued monitoring and research to better understand the disease and develop effective management strategies. This review has highlighted the up-to-date information on Verticillium wilt and management strategies. The study also helps the scientific community understand this devastating plant disease by offering a thorough review of the situation.

Mechanisms of Surfactin from Bacillus subtilis SF1 against Fusarium foetens: A Novel Pathogen Inducing Potato Wilt.

Fusarium wilt is a severe and worldwide disease in potato cultivation. In this study, Fusarium foetens was first identified as the pathogen of potato wilt. Bacillus subtilis SF1 has the potential for controlling potato wilt induced by F. foetens, resulting in a mycelium growth inhibition of 52.50 ± 2.59% in vitro and a significant decrease in incidence rate by 45.56% in vivo. This research highlighted the antifungal activity of surfactin from B. subtilis SF1 and attempted to reveal the unknown antifungal mechanisms. Surfactin inhibited F. foetens mycelium growth beyond the concentration of 20 μg/μL. Surfactin-treated mycelium appeared to have morphological malformation. Surfactin enhanced reduced glutathione production and caused the increase in values of the extracellular fluids in OD260 and OD280. Surfactin induced differential protein expression and changed the genes' transcription levels. Surfactin binds to fungal DNA via groove-binding mode, with a binding constant of Kb 2.97 × 104 M-1. Moreover, B. subtilis SF1 harbored genes encoding plant-promoting determinants, making potato seedlings grow vigorously. The results will help provide a comprehensive understanding of the mechanisms of surfactin against filamentous fungi and the application of surfactin-producing microbial in the biocontrol of plant pathogenic fungi.

Early detection of Verticillium wilt of potatoes using near-infrared spectroscopy and machine learning modeling

Verticillium wilt, primarily caused by the pathogen Verticillium dahliae, is an economically devastating disease of potato crops. Early detection of this disease is critical in informing growers to apply management measures to reduce Verticillium wilt incidence and severity. However, early detection of V. dahliae can be challenging due to the cryptic nature of its symptom emergence and expression. This paper presents the implementation of near-infrared (NIR) spectroscopy coupled with machine learning to develop an efficient and objective tool for the early detection of Verticillium wilt in potato plants. Two artificial neural network (ANN) models were developed using the raw absorbance values within the 1596 – 2396 nm light spectral range as inputs to predict photosynthetic rate (A), transpiration rate (E), and stomatal conductance (gs), as well as predict whether plants were infected or non-infected. The results showed high accuracy for Model 1 (R = 0.89 using all samples from trial 1) with a deployment accuracy of R = 0.76 using all samples from trial 2. High accuracy was also obtained for Model 2 using samples from trial 1 (94 %) with a deployment accuracy of 84 % using samples from trial 2. Results showed that V. dahliae presence could correctly be identified in plants two days after inoculation (DAI) without any visible symptomatology. These model types have never been presented for Verticillium wilt of potato and show high potential in introducing a cost-effective, efficient, and user-friendly means for growers to detect Verticillium wilt before symptoms occur.

Dose-response relationship of Ralstonia solanacearum and potato in greenhouse and in vitro experiments.

Ralstonia solanacearum is the causative agent of bacterial wilt of potato and other vegetable crops. Contaminated irrigation water contributes to the dissemination of this pathogen but the exact concentration or biological threshold to cause an infection is unknown. In two greenhouse experiments, potted potato plants (Solanum tuberosum) were exposed to a single irrigation with 50mL water (non-invasive soil-soak inoculation) containing no or 102 - 108 CFU/mL R.solanacearum. The disease response of two cultivars, Kondor and HB, were compared. Disease development was monitored over a three-month period after which stems, roots and tubers of asymptomatic plants were analyzed for latent infections. First wilting symptoms were observed 15 days post inoculation in a plant inoculated with 5x109 CFU and a mean disease index was used to monitor disease development over time. An inoculum of 5x105 CFU per pot (1.3x102 CFU/g soil) was the minimum dose required to cause wilting symptoms, while one latent infection was detected at the lowest dose of 5x102 CFU per pot (0.13 CFU/g). In a second set of experiments, stem-inoculated potato plants grown in vitro were used to investigate the dose-response relationship under optimal conditions for pathogen growth and disease development. Plants were inoculated with doses between 0.5 and 5x105 CFU/plant which resulted in visible symptoms at all doses. The results led to a dose-response model describing the relationship between R.solanacearum exposure and probability of infection or illness of potato plants. Cultivar Kondor was more susceptible to brown-rot infections than HB in greenhouse experiments while there was no significant difference between the dose-response models of both cultivars in in vitro experiments. The ED50 for infection of cv Kondor was 1.1x107 CFU. Results can be used in management strategies aimed to reduce or eliminate the risk of bacterial wilt infection when using treated water in irrigation.

Determination of Bioactive Compounds Against Bacterial Wilt of Potato (Ralstonia pseudosolanacearum sp. nov.) in Psidium guajava and Pelargonium zonale Leaf Extracts

Common guava (Psidium guajava) and Pelargonium (Pelargonium zonale) have shown in-vitro antibacterial activity against Ralstonia pseudosolanacearum sp. nov. in previous studies. However, their phytochemical constituents and bioactive compounds against the pathogen have not been identified. The present study investigated the phytochemical components of P. guajava and P. zonale leaf extracts by phytochemical screening and gas chromatography-mass spectrometry (GC-MS). Phytochemical screening was done using different solvents while 100 mg of the dried ethanolic extract pastes from each plant sample was subjected to GC-MS analysis. Automated mass spectral deconvolution and identification system software (AMDIS, US) was used to analyze chromatograms and spectra representing individual compounds. Compound identification was performed by comparing each of the mass spectra with the database of NIST 11 (Gaithersburg, MD, USA), Wiley 7N (John Wiley, NY, USA) and by comparing the calculated Kovats linear retention indices using retention times of n-alkane series against the values in the NIST webbook. Flavonoids, phenols, alkaloids, saponins, terpenoids and tannins were detected in both plant samples. GC-MS analysis revealed presence of 35 and 26 compounds from P. zonale and P. guajava respectively. Both P. zonale and P. guajava had 7 similar compounds with antibacterial properties; Fumaric acid, Phytol, Pyrogallol, 4-Hydroxybenzoic acid, Shikimic acid, Protocatechuic acid and 3, 4, 5-Trihydroxybenzoic acid ethyl ester but P. zonale had one additional antibacterial compound; Lactic acid. In both cases, Shikimic acid had the highest percent peak areas of 3.2% for P. zonale and 6.8% P. guajava respectively. Therefore, P. zonale and P. guajava can serve as alternative sources of active ingredients for formulation of commercial botanicals for the management of bacterial wilt of potato.

Potato wilt caused by co-infection of Fusarium spp. and Verticillium dahliae in potato plants

Potato wilt caused by co-infection of Fusarium spp. and Verticillium dahliae in potato plants

Ralstonia Strains from Potato-Growing Regions of Kenya Reveal Two Phylotypes and Epidemic Clonality of Phylotype II Sequevar 1 Strains.

Bacterial wilt, caused by the Ralstonia solanacearum species complex (RSSC), is the most destructive potato disease in Kenya. Studies were conducted to (i) determine the molecular diversity of RSSC strains associated with bacterial wilt of potato in Kenya, (ii) generate an RSSC distribution map for epidemiological inference, and (iii) determine whether phylotype II sequevar 1 strains exhibit epidemic clonality. Surveys were conducted in 2018 and 2019, in which tubers from wilting potato plants and stem samples of potential alternative hosts were collected for pathogen isolation. The pathogen was phylotyped by multiplex PCR and 536 RSSC strains typed at a sequevar level. Two RSSC phylotypes were identified, phylotype II (98.4%, n = 506 [sequevar 1 (n = 505) and sequevar 2 (n = 1)]) and phylotype I (1.6%, n = 30 [sequevar 13 (n = 9) and a new sequevar (n = 21)]). The phylotype II sequevar 1 strains were haplotyped using multilocus tandem repeat sequence typing (TRST) schemes. The TRST scheme identified 51 TRST profiles within the phylotype II sequevar 1 strains with a modest diversity index (HGDI = 0.87), confirming the epidemic clonality of RSSC phylotype II sequevar 1 strains in Kenya. A minimum spanning tree and mapping of the TRST profiles revealed that TRST27 '8-5-12-7-5' is the primary founder of the clonal complex of RSSC phylotype II sequevar 1 and is widely distributed via latently infected seed tubers. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Antibacterial activity of guava, moringa, camphor bush and pelargonium extracts against bacterial wilt (Ralstonia pseudosolanacearum sp. nov.) of potato

Bacterial wilt (Ralstonia pseudosolanacearum sp. nov.) is a major disease devastating global potato production. Proposed management options are mostly expensive and ineffective. This has necessitated efforts to develop cheaper and eco-friendly management options such as use of botanicals. Antibacterial activity of ethanol and acetone plant extracts from guava (Psidium guajava), drumstick (Moringa oleifera), camphor bush (Tarchonanthus camphoratus) and pelargonium (Pelargonium zonale) against R. pseudosolanacearum sp. nov. was evaluated in-vitro at a concentration of 100 mg/mL of 1 % Dimethlysulfoxide (DMSO) using disk diffusion technique. The R. pseudosolanacearum sp. nov was isolated from infected haulms collected from potato growing field at the University of Nairobi. The most effective extracts were subjected to further screening at different concentrations to determine their minimum inhibitory concentrations (MICs). All the four plant extracts showed varied antibacterial efficacy. P. zonale leaves extract was the most effective with growth inhibition zone of 18.73 mm and 18.60 mm for ethanol and acetone solvents respectively. The average of growth inhibition zones for each plant extract was not significantly different at p ≤ 0.05 among extraction solvents. The minimum inhibitory concentration (MIC) results showed that antibacterial activity of P. zonale and P. guajava leaf started at 6.25 mg/mL with growth inhibition zones of 7.67 and 8.0 mm for ethanol and acetone solvents respectively. P. zonale and P. guajava leaf extracts exhibited significantly higher antibacterial activity at p ≤ 0.05 compared to other extracts. Thus, further research should be conducted to assess their antibacterial potency against R. pseudosolanacearum sp. nov. both in-vivo and under field condition.

Resistance to Bacterial Wilt in Solanum commersonii Dun.

The levels of resistance to bacterial wilt (BW) of potatoes caused by Ralstonia solanacearum (Rs) are limited. Solanum commersonii (cmm) is a wild tuber-bearing potato highlighted for its resistance to BW. This research aimed to (i) characterize cmm genotypes for resistance to Rs (race 3, biovar 2) using a soil inoculation method, (ii) determine to what extent resistance in cmm is transmissible through sexual reproduction to a susceptible genetic background, and (iii) determine the relationships between a set of Rs strains (race 3, biovar 2) and cmm genotypes in the expression of resistance. The screening was performed under controlled conditions of temperature and light. Accessions collected from different regions of Uruguay showed diversity for resistance to BW: some genotypes were asymptomatic in the response, while for others the symptoms were similar to the susceptible control. Two cmm genotypes with contrasting responses to BW were crossed, and an offspring of 121 genotypes was obtained. The distribution of BW resistance levels in the progeny suggested a polygenetic control for BW resistance; though this conclusion is preliminary regarding that one of the cmm parents was triploid. A factorial experiment using five R. solanacearum strains isolated in Uruguay and five cmm clones showed differences in the virulence between strains. There was no interaction between plant genotype and bacterial isolate, and therefore, under the conditions of this research, BW resistance in cmm was not dependent on the isolate of the pathogen.

Application of Secondary Metabolites of Two Pseudomonas fluorescens Isolates to Control Bacterial Wilt of Potato

The focus of this research was to determine how secondary metabolites from two isolates of Pseudomonas fluorescens (P8 and P60) affected potato plant resistance to bacterial wilt (Ralstonia solanacearum) as well as potato growth and productivity. For four months, this experiment was carried out at Serang Village’s potato field, in Karangreja District, Purbalingga Regency, at an altitude of 1285 m above sea level, with Andisol soils, an average temperature of 22.31 C, and relative humidity of 84.09%. A randomized block design was used with a control treatment, drenching with 1.5 g/L bactericide (20% streptomicin sulphate) administered six times, and drenching with secondary metabolites of P. fluorescens P8 or P. fluorescens P60 administered three, six, nine, and 12 times. Each treatment was carried out five times. Each treatment resulted in a different incubation period, disease intensity, infection rate, plant height, number of tubers, tuber weight per plant, wet and dry weight of crop, fresh and dry weight of root, number of branches, and phenolic compound analysis. The results showed that applying P. fluorescens P8 and P. fluorescens P60 secondary metabolites to potato plants can induce resistance by increasing the content of phenolic compounds in the plants. Drenching with secondary metabolites from P. fluorescens P8 or P. fluorescens P60 12 times can reduce the incubation period by 9.23%, the intensity of disease by 75%, and the incidence of disease by 53.57%. Plant height, crop dry weight, root fresh weight, root dry weight, number of tubers, and tuber weight per plant can all be increased by using secondary metabolites.
 Keywords: bacterial wilt, potato, Pseudomonas fluorescens, secondary metabolites.

Effectiveness of bioactive compounds in amending the soil infested with soil-borne Ralstonia solanacearum of potato

Three natural bioactive compounds, viz. cow dung, bee propolis and turmeric powder were applied to amend the Ralstonia solanacearum infested soil of potato. Sun dried cow dung @ 30 t/ha, aqueous extraction of turmeric powder @ 30 kg/ha and propolis @ 5 lit/ha were applied to the inoculated soil by mixing with field soil in SAU (Dhaka) and BARI (Gazipur). Data on pH, organic matter, total cfu/ml and avirulent cfu/ml of the treatment applied soil and per cent disease index (PDI) of bacterial wilt of potato were recorded. Significant difference in soil pH and per cent organic matter (OM) occurred in all the amended soil as compared to control. A decreased total cfu/ml of R. solanacearum occurred in all the treated soil, but propolis (8.2 X 107) and cow dung (1.1 X 108) showed the lowest count. However, in increasing the avirulent count of R. solanacearum, turmeric powder (1.8 X 109) showed the highest count compared to other amended soil. Significant disease reduction over control was also observed in all the treatments, but propolis (45.65%) and turmeric powder (43.48%) showed the best results in wilt disease reduction. J. Biodivers. Conserv. Bioresour. Manag. 2021, 7(1): 43-50

Dickeya dadantii (bacterial wilt and soft rot of ornamentals and potato)

Dickeya dadantii (bacterial wilt and soft rot of ornamentals and potato)

Dickeya dadantii (bacterial wilt and soft rot of ornamentals and potato)

This datasheet on Dickeya dadantii covers Identity, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Seedborne Aspects, Impacts, Prevention/Control, Further Information.

Screening of Bacillus subtilis HAAS01 and Its Biocontrol Effect on Fusarium wilt in Sweet Potato

Fusarium wilt, a disease caused by Fusarium oxysporum f.sp batatas (Fob) is an important disease in sweet potato production. Using endophytic bacteria for biological control of sweet potato diseases is one of the important ways. A Bacillus subtilis with antagonistic effect on Fusarium wilt of sweet potato was isolated from soil by confrontation culture. According to the biological characteristics, 16S rDNA sequence analysis, and physiological and biochemical analysis, the Bacillus subtilis HAAS01 was named. A pot experiment was conducted for the biological control experiment of strain HAAS01, and the endogenous hormone content, antioxidant enzyme activity, soluble protein content, and related gene expressions of sweet potato plants were detected. The results showed that the HAAS01 strain could promote the production of endogenous hormones and resist the infection of plant diseases together with defensive enzymes and upregulation of related gene expressions. In summary, Bacillus subtilis HAAS01 was effective in controlling Fusarium wilt of sweet potato and has potential for application and development.