콩 불마름병 방제를 위한 살균제 선발

Bacterial pustule of soybean is a foliar disease caused by Xanthomonas axonopodis pv. glycines. The organism produces pustules which causes premature defoliation and ultimately results in significant reduction in seed yield and quality. Use of resistant cultivars can be a cost effective and eco-friendly approach to address the issue. This study was aimed at development of a rapid and reliable in-vitro screening method and screening of soybean genotypes for the identification of resistance sources to bacterial pustule disease. One hundred thirty-six soybean genotypes including released varieties, indigenous and exotic germplasm were screened by excised leaf technique for their reaction to bacterial pustule disease. An improved in-vitro technique for screening of bacterial pustule disease was developed. Rooting and survival studies indicated that soybean leaves excised from 25 days old plants could survive up to 30 days at room temperature in plain water. Inoculation with bacterial suspension of 107 to 109 colony forming units (cfu/ml) at 27±1°C under the photoperiod of 12h/day light showed initiation of chlorotic lesions 48 hours after inoculation. Based on the latent period and appearance of the chlorotic lesions, the genotypes were classified as susceptible, moderately resistant and resistant. Four soybean genotypes (TS-3, P-4-2, Hara Soya and Himso 1685) were resistant while, seventeen genotypes (AMS MB5-19, Bhatt, DSb-12, JS-335, JS93-05, MACS- 1188, MAUS- 71, PK-262, PS- 1241, Pusa-5, RKS- 18, SL-688, SL-744, SL-958, SL97-52, SL-979, and T99-76) were moderately resistant and rest of the genotypes were susceptible to bacterial pustule disease.

This chapter discusses the early season diseases - seed decay (Phomopsis longicolla), damping-off (Rhizoctonia solani and Pythium), root and stem rot (Phytophthora sojae); mid-season diseases - bacterial pustule (Xanthomonas axonopodis pv. glycines), viral diseases (Bean pod mottle virus BPMV and Soybean mosaic virus SMV), Sclerotinia stem rot (Sclerotinia sclerotiorum), Frogeye leaf spot (Cercospora sojina), soyabean rust (Phakopsora meibomiae and P. pachyrhizi); late-season diseases - soyabean cyst (Heterodera glycines), stem canker (Diaporthe phaseolorum var. caulivora and D. phaseolorum var. meridionalis), sudden death syndrome (Fusarium virguliforme), leaf blight (Cercospora kikuchii), anthracnose (Colletotrichum truncatum), and charcoal rot (Macrophomina phaseolina) of soyabeans. Disease management practices are also discussed.

Identification of benzoic acid and 3-phenylpropanoic acid in tobacco root exudates and their role in the growth of rhizosphere microorganisms

Preparatory work for the pest categorisation of three bacteria listed in the annexes of the Council directive 2000/29/EC Erwinia amylovora Winslow et al. Xylophilus ampelinus (Panagopoulos) Willems et al. Clavibacter michiganensis subsp. insidiosus(McCulloch) Davis et al

The current research work was designed to evaluate, test, and characterize effective antifungal extracts from Trichoderma isolates against coffee wilt pathogen ( Gibberella xylarioides) . For extraction of antifungal extracts from fungal mycelium different organic solvents, viz., chloroform, ethanol, methanol, ethyl acetate, n-hexane and butane were used. A direct bioautographic procedure was conducted, involving spraying suspension of Fusarium xylarioides on Thin Layer Chromatography ( tlc) plates developed in solvents of varying polarities to detect a number of antifungal substances present in the extracts. Moreover, in vitro antagonistic bioassays were performed to evaluate and determine the potentiality of Trichoderma isolates as biocontrol agents against F. xylarioides. Antifungal extracts were successfully extracted from malt extract agar medium with all organic solvents used except from hexane. Bioautography assay revealed 60 zones of inhibition spots and the highest inhibition zone was observed in aut 5 (51 mm) and aut 6 (44 mm) with ethanol extract at R f value of 0.43. In in vitro bioassay, the highest mean inhibitory effect on the growth of the pathogen was achieved by aut 2 (77.4%) isolate in dual culture. In general, tlc -directed bioautography assay was found to be useful in isolating active compounds with antifungal activity and all Trichoderma isolates significantly reduced mycelial growth of the test pathogen compared to the control under in vitro condition.

Bacterial pustule caused by Xanthomonas citri pv. glycines (syn. X. axonopodis pv. glycines) is an important bacterial disease for soybean production worldwide. Currently, the planting of resistant soybean cultivars is the main measure for control of the disease. Therefore, the objectives of this study were to determine the aggressiveness of different X. citri pv. glycines isolates and to establish a new protocol to evaluate the reaction of soybean cultivars to bacterial pustule under greenhouse conditions. The molecular analysis based on the entire 16S rRNA gene sequence revealed that the isolates GDM 01, GDM 02, 333 and 87-2 belong to the X. citri pv. glycines pathovar with 100% identity with the pathotype strain K29 of this bacterium. Differences in aggressiveness were observed among the X. citri pv. glycines isolates. There were differences in the reaction of the soybean cultivars to bacterial pustule, depending on the inoculation method. The isolates 333, GDM 01 and GDM 02 were the most aggressive, while 87-2 and GDM 03 were the least aggressive ones. The best conditions for inoculation of the soybean plants were in the V3 vegetative growth stage with the inoculum concentration of 108 CFU mL−1, and moist chamber for 24 h before and after inoculation. Spraying without injury was the quickest and most practical inoculation method to screen soybean genotypes for resistance to bacterial pustule in breeding programs. Further, this method of inoculation closely simulates the natural bacterial infection under field conditions and produces typical symptoms of the disease. The standard brush inoculation method overestimated disease severity, so we do not recommend this method for the evaluation of bacterial pustule resistance in soybean breeding programs.

Bacterial blight, caused by Xanthomonas citri pv. punicae (Xcp), severely impacts the global pomegranate industry, with alarming yield losses up to 80%. This pathogen becomes a glitch in the pomegranate industry, leading to reduced commercial pockets globally, especially in Pakistan. The objective of this study was to conduct biochemical characterisation and in vitro evaluation of copper compounds and antibiotics against Xcp, for optimal fruit quality and yield. The pathogen was isolated from infected tissues of the pomegranate, and various biochemical tests were performed to identify the bacteria. Pathogenicity was confirmed using the pin-prick and infiltration method on cv. Golden. The in vitro efficacy of antibiotics and copper compounds was assessed using the disk diffusion method against Xcp. The pathogen was aseptically cultured via the streak plate method, and disks impregnated with different chemical concentrations were placed on solidified media. A control disk was treated with sterile water containing 1% v/v surfactant. Plates were incubated at 28 ± 2°C for 48 and 72h to observe bacterial growth inhibition. Biochemical analysis showed positive results for the oxidase test, catalase test, KOH solubility test, gelatin liquefaction, and starch hydrolysis test, while Gram staining was negative. Antibacterial efficacy was determined by measuring inhibition zones after 48 and 72h of incubation. The highest inhibition zones, measuring 29.55mm and 37.73mm at 48 and 72h, respectively, were recorded with 550µg/ml oxytetracycline hydrochloride, followed by streptomycin sulfate (550µg/ml) with zones of 29.12mm and 32.42mm. In contrast, copper-based compounds, particularly copper sulfate (2000µg/ml), exhibited the lowest inhibition, with zones of 8.85mm and 8.86mm at the respective time intervals. A comparative analysis demonstrated that antibiotics showed outstanding and prodigious results compared to copper compounds. The results of this experiment demonstrate the effectiveness of oxytetracycline hydrochloride and streptomycin sulfate in inhibiting the radial growth of Xcp under controlled conditions. Furthermore, changes in dosage/concentration, time of application, and field application method may help researchers with field-oriented results in the future.

Aqueous and methanol extracts of Allium sativum (clove and peel) were investigated for its in vitro antibacterial properties against four marine pathogens, Aeromonas hydrophila, Vibrio anguillarum, Vibrio alginolyticus, and Vibrio harveyi. Antibacterial activity of different concentrations of aqueous and methanol garlic extracts were evaluated based on the inhibition zone using disc-diffusion method, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. The aqueous extract of A. sativum (clove and peel) had no antibacterial effect against the pathogenic bacteria tested whereas the clove extract of methanol had inhibitory effects on the growth of all pathogenic bacteria tested. The maximum zone of inhibition was observed in A. hydrophila and the minimum was observed in V. anguillarum and V. harveyi. The MIC and MBC values revealed that A. hydrophila was able to be inhibited by supernatant extract of clove at lower concentration (0.6 mg/ml) while other pathogens are inhibited at slightly higher concentration. This study suggests that clove extract of A. sativum has the potential to be used as phytobiotics in controlling the growth of marine pathogens.

Ultrastructural and immunocytochemical investigation of pathogen development and host responses in resistant and susceptible wheat spikes infected by Fusarium culmorum

Abstract. Prihatiningsih N, Arifianto RA, Istiqomah D, Irwandhi. 2026. Evaluation of Bacillus cereus bioinoculants for biocontrol of bacterial leaf blight and growth promotion in shallots. Asian J Agric 10 (1): g100136. https://doi.org/10.13057/asianjagric/g100136. Bacterial leaf blight (Xanthomonas axonopodis pv. allii) is a major disease of shallots (Allium cepa) that requires continuous control. The use of rhizobacterial bioinoculants is an environmentally friendly strategy that serves a dual role, as a biocontrol and a plant growth promoter. This study aims to evaluate the bioinoculant Bacillus cereus in controlling bacterial leaf blight and increasing shallot growth. This research was conducted using a factorial Randomized Block Design (RBD) with 2 factors (cropping pattern and biofertilizer) and 3 replications. All B. cereus treatments inhibited the pathogen's growth in vitro via a bacteriostatic mechanism, with isolate Bm3 producing the largest inhibition zone (14.75 mm). In addition, each B. cereus isolate can produce siderophores and proteases, as well as dissolve phosphate. In field tests, B. cereus treatment can significantly reduce disease development compared to the control. The consortium treatment tended to show the highest efficacy, with low disease intensity (8.33%), control effectiveness of 51.93%, reduced AUDPC (23.50%), and increased nutrient uptake of shallot. These results indicate that the B. cereus bioinoculant, in the form of a consortium, has the potential to be an effective multifunctional inoculant for controlling bacterial leaf blight and enhancing growth in sustainable shallot cultivation.

Kamran khan, Sufian Ikram, Ammara Noreen, Muhammad Ashfaq, Muhammad Jafar Jaskani & Waqar Shafqat.2021.Citrus rootstock characterization against citrus canker and evaluation of antibiotics effect against Xanthomonas axonopodis pv. citri.Journal of Innovative Agriculture.volume 8, issue 2, Pages 1-8. Citrus canker (X. axonopodis pv. citri) widespread bacterial disease which limits citrus productivity and causes quality deterioration. Citrus canker is mostly a leaf-spotting and fruit rind-blemishing disease, but under highly favorable conditions, infections cause defoliation, shoot dieback, and fruit drop. Citrus rootstocks exert a high degree of influence to scions in fruit production and plant susceptibility to diseases including citrus canker. Keeping in view the importance of citrus rootstock present study was planned to evaluate the performance of citrus rootstocks against citrus canker and antibiotics response to control X. axonopodis pv. citri. Eleven exotic citrus rootstocks were selected to evaluate against canker which was inoculated by grafting. Disease index was observed after 9 months of inoculation. Five different commercially available antibiotics were selected for the Invitro treatment, applied at 300, 400 and 500ppm. Inhibition zone was observed at four time points (24, 48, 72 and 96 hours). Kirumakki showed maximum resistance followed by Rangpur Poona nucellar and X639 while Rough lemon was highly susceptible. In Invitro evaluation maximum inhibition zone was expressed by Kanamycin sulphate at 500 ppm followed by Streptomycin sulphate. Lincomycin showed minimum inhibition zone as compared with control (Distilled water, No inhibition). Biochemical analysis exhibited that the disease index (%) decrease with increase of total phenolics contents and total protein contents. Whereas disease index had increasing trend with TSS. This study concludes that according to rootstocks evaluation Kirumakki and Rangpur Poona nucellar showed resistant performance while, on other hand Kanamycin Sulphate having maximum inhabitation against canker.

Soybean [Glycine max (L.) Merrill] is one of the most important oilseed crop in India as well as in the World belonging to family leguminoceae. Colletotrichum truncatum, the causal organism of anthracnose/ pod blight of soybean is one of the destructive pathogen. Seven systemic fungicides (@ 500, 1000 ppm each), seven bio-agents and seven botanicals @ 10% and 20% each were evaluated in vitro against C. truncatum using PDA as basal medium. The results revealed that all the fungicides, bio-agents and botanicals were found fungistatic and significantly inhibited the mycelial growth of the test pathogen over control. Among the fungicides, carbendazim and propiconazole recorded highest mean inhibition (96% @1000 ppm and 94.33% @ 500 ppm) of mycelial growth of the test pathogen. Among phyto-extracts tested, garlic extract recorded highest mean inhibition (79.66 @10% and 87.33 @20%) of mycelial growth of the test pathogen. Among bio-agents tested, Trichoderma asperellum recorded highest mean mycelial inhibition (74.88) of the test pathogen.

Rainfed soybean (Glycine max) crops in the northern coastal region of New South Wales were surveyed from 1985 to 1987 for the prevalence and severity of diseases. Sixteen diseases were recorded over the 3 seasons, but only rust (Phakopsora pachyrhizi), black leaf blight (Arkoola nigra) and bacterial pustule (Xanthomonas campestris pv. glycines) were present each season. Rust was the most significant disease, infecting 50, 20 and 6% of crops in 1985, 1986 and 1987. The severity of rust was related to rainfall and temperature after flowering, with the most severe outbreaks in the higher rainfall area of the lower Richmond Valley. Black leaf blight was also significant and occurred in 39, 10 and 27% of crops in 1985, 1986 and 1987, but in most crops severity was low. The other diseases recorded were downy mildew (Peronospora manschurica), root and stem rot (Phytophthora megasperma f. sp. glycinea), stem canker (Rhizoctonia sp.), pod and stem blight (Phomopsis spp.), anthracnose (Colletotrichum spp.), seedling blight (Rhizoctonia sp.), stem rot (Phytophthora sp.), white mould (Sclerotinia sclerotiorum), flower blight (Botrytis cinerea), leaf spot (Phoma sp.), bacterial blight (Pseudomonas syringae pv. glycinea), mosaic (soybean mosaic virus) and orange bark (not identified). All of these diseases were generally of low prevalence and severity.

‘NC‐Tinius’ soybean [ Glycine max (L.,) Merr.] (Reg. No. CV‐503, PI 664027) was cooperatively developed and released by North Carolina State University (NCSU) and the North Carolina Agricultural Research Service. It was first tested in North Carolina yield trials in 2003. NC‐Tinius is a determinate, maturity‐group‐V, conventional cultivar. It is a high‐yielding conventional line adapted to the northern and central regions of eastern North Carolina. It was derived from the cross of the low‐palmitate and low‐linolenate conventional line TN99‐76,077 to a high‐yielding conventional line V91‐3036. In the NCSU breeding trials (11 environments), NC‐Tinius averaged 3443 kg ha −1 , or 353 kg ha −1 more than ‘5601T’, under full‐season conditions. In eight average‐ to high‐yield environments in the North Carolina Official Variety Trials, NC‐Tinius produced significantly higher yields (4031 kg ha −1 ) than did the standard cultivar 5601T in narrow (19 cm) row spacing. Seed protein and oil contents were similar to those of 5601T. NC‐Tinius is resistant to Soybean mosaic virus (G1), frogeye leaf spot (caused by Cercospora sojina Hara), bacterial pustule [caused by Xanthomonas campestris pv. glycines (Nakano) Dye], and stem canker (caused by Diaporthe phaseolorum var. meridionalis ) and is moderately resistant to sudden death syndrome (caused by Fusarium solani f. sp. glycines ).

Soybean [Glycine max (L.) Merr.] germplasm line LG04‐6863 (Reg. No. GP‐364, PI 658307) was developed and released by the University of Missouri Agricultural Experiment Station, Delta Center, Portageville, MO, the USDA–ARS, and the Illinois Agricultural Experiment Station, Urbana, IL. It was approved for release May 2009. LG04‐6863 is an F5 plant selection composited in the F6 generation from ‘Rend’ × LG97‐9486. It has shown high yield potential in tests across the southern United States with 38% of its pedigree from plant introductions and unique diversity not known in soybeans adapted to southern U.S. environments. LG04‐6863 (relative maturity 4.4) has yielded, 101, 100, and 97% of yields of ‘Asgrow AG4403’ (3193, 4047, and 3833 kg ha−1), a widely grown Roundup Ready cultivar of similar maturity, across eight locations in the USDA Uniform Preliminary Early Group IV Test–Southern States; eight locations in the United Soybean Board Southern Early Group IV Diversity Trials; and 15 southeastern Missouri tests, respectively. It is resistant to stem canker and bacterial pustule. Reaction to phytophthora root rot (PRR; caused by Phytophthora sojae M.J. Kaufmann & J.W. Gerdemann) is unknown, but LG04‐6863 has shown good performance on heavy clay soils where PRR often occurs. Soybean introductions have been under utilized in breeding programs. LG04‐6863 will have use as an elite parent in soybean breeding programs to improve yield and broaden the germplasm base.