Mikroorganisma Antagonis Sebagai Kawalan Biologi Penyakit Utama Padi

2014 ◽  
Vol 70 (6) ◽  
Author(s):  
Allicia Jack ◽  
Kogeethavani Ramachandran
Keyword(s):  
Paenibacillus Polymyxa ◽  
Gene Bank ◽  
Blast Disease ◽  
Dual Culture ◽  
Bacterial Isolates ◽  
Rice Soils ◽  
16S Rdna Sequence ◽  
16S Rdna Sequence Analysis ◽  
Fungal Isolates

In present study, 26 microbes consisted of 11 fungal isolates and 16 bacterial isolates were screened against blast disease pathogen (Pyricularia oryzae). All isolates were screened in vitro via dual culture bioassay. All fungal isolates collected were isolated from aerobic rice soils and the endophyic bacteria were isolated from the stem of healthy rice plants. Five isolates have been identified to be potential biocontrol agents as they recorded high PIRG (percentage inhibition of radial growth) values of more than 80%. Two isolates were identified as Trichoderma (F15 and F16) while the rest of them were bacteria isolates (I5, I6 and I16). 16S rDNA sequence analysis results showed that all three bacterial isolates were 100% similar to Paenibacillus polymyxa (Gene Bank assession number:  GU332610.1).

scholarly journals Antagonistic Activity and Characterization of Indigenous Soil Isolates of Bacteria and Fungi Against Onion Wilt Incited by Fusarium sp

2021 ◽  
Author(s):  
Hilda Karim ◽  
Andi Asmawati ◽  
Oslan Jumadi
Keyword(s):  
Fusarium Oxysporum ◽  
Evolutionary Relationship ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Bacterial Isolates ◽  
Gene Markers ◽  
Culture Techniques ◽  
Fungal Isolates ◽  
Bacteria And Fungi

Abstract Tuber rot disease due to phytopathogen Fusarium oxysporum f. sp. cepae (Foc) infection is one of the main factors causing the decreasing amount of global shallot production. This study aims to find bacteria and fungi candidates which have Foc antagonistic activity through in vitro tests using dual culture techniques. A total of five bacterial isolates and three fungal isolates isolated from the rhizosphere of healthy onion plants showed the ability to inhibit Foc growth. B1 and B4 bacterial isolates had an average inhibitory capability of 65.93% and 72.27% respectively. Whereas C1 and C2 fungal isolates have the ability to inhibit the growth of Foc by as much as 74.82% and 67.76% respectively. The four tested microbial isolates were able to significantly inhibit Foc activity in vitro based on the ANOVA test, with values α = 0.05, and n = 3. Molecular analysis based on 16S-rRNA markers showed bacterial isolates B1 and B4 have an evolutionary relationship with B. subtilis. Whereas fungi C1 and C2 have evolutionary relationships with Aspergillus tubingensis and Trichoderma asperellum respectively, based on internal transcribed spacer (ITS) gene markers. The results of this study can be used to develop indigenous microbial consortiums as biological control agents for phytopathogenic fungi Fusarium oxysporum f. sp. cepae (Foc) on shallots.

Papaya shoot tip associated endophytic bacteria isolated from in vitro cultures and host–endophyte interaction in vitro and in vivo

2007 ◽  
Vol 53 (3) ◽  
pp. 380-390 ◽  
Author(s):  
Pious Thomas ◽  
Sima Kumari ◽  
Ganiga K. Swarna ◽  
T.K.S. Gowda
Keyword(s):  
Culture Medium ◽  
Carica Papaya ◽  
In Vitro Cultures ◽  
Dependent Manner ◽  
16S Rdna Sequence ◽  
16S Rdna Sequence Analysis ◽  
Single Organism ◽  
Dose Dependent

Fourteen distinct bacterial clones were isolated from surface-sterilized shoot tips (~1 cm) of papaya (Carica papaya L. ‘Surya’) planted on Murashige and Skoog (MS)-based papaya culture medium (23/50 nos.) during the 2–4 week period following in vitro culturing. These isolates were ascribed to six Gram-negative genera, namely Pantoea ( P. ananatis ), Enterobacter ( E. cloacae ), Brevundimonas ( B. aurantiaca ), Sphingomonas , Methylobacterium ( M. rhodesianum ), and Agrobacterium ( A. tumefaciens ) or two Gram-positive genera, Microbacterium ( M. esteraromaticum ) and Bacillus ( B. benzoevorans ) based on 16S rDNA sequence analysis. Pantoea ananatis was the most frequently isolated organism (70% of the cultures) followed by B. benzoevorans (13%), while others were isolated from single stocks. Bacteria-harboring in vitro cultures often showed a single organism. Pantoea, Enterobacter, and Agrobacterium spp. grew actively on MS-based normal papaya medium, while Microbacterium, Brevundimonas, Bacillus, Sphingomonas, and Methylobacterium spp. failed to grow in the absence of host tissue. Supplying MS medium with tissue extract enhanced the growth of all the organisms in a dose-dependent manner, indicating reliance of the endophyte on its host. Inoculation of papaya seeds with the endophytes (20 h at OD550 = 0.5) led to delayed germination or slow seedling growth initially. However, the inhibition was overcome by 3 months and the seedlings inoculated with Pantoea, Microbacterium, or Sphingomonas spp. displayed significantly better root and shoot growths.

scholarly journals ASAI KEMAMPUAN BAKTERI ENDOFIT DARI KACANG TANAH DALAM MENGHAMBAT PERTUMBUHAN Sclerotium sp. PADA KECAMBAH KACANG TANAH

2020 ◽  
Vol 14 (2) ◽  
pp. 178-186
Author(s):  
Lisa Novita Arios ◽  
Dwi Suryanto . ◽  
Kiki Nurtjahja . ◽  
Erman Munir .
Keyword(s):  
Endophytic Bacteria ◽  
Culture Method ◽  
Dry Weight ◽  
Dual Culture ◽  
Seedling Height ◽  
Bacterial Isolates ◽  
Peanut Seed ◽  
Number Of Leaves

Assay on ability of endophytic bacteria isolated from peanut to inhibit Sclerotium sp. growth in peanut seedlings.   A study on assay of ability of endophytic bacteria to inhibit Sclerotium sp. in peanut seedling has been done. The bacteria were isolated from peanut healthy plants, while Sclerotium sp. was isolated from infected peanaut plant. Antagonistic assay was conducted by dual culture method.  In vivo assay of inhibiting Sclerotium sp. was conducted by dipping peanut seed in bacterial solution, and planting the seed in soil:compost (3:1) growing media. Six endophytic bacterial isolates showed to inhibit the growth of Sclerotium sp. in vitro. LN1 seemed to inhibit more of Sclerotium sp., while LN5 showed to inhibit less. Two potential isolates LN1 of gram-negative and LN2 of gram-positive using for further study showed to decrease more of dumping off. It also seemed that the isolates increased the seedling height, number of leaves, and dry weight.

scholarly journals Comparison of Bacterial Community Structures in the Rhizoplane of Tomato Plants Grown in Soils Suppressive and Conducive towards Bacterial Wilt

1999 ◽  
Vol 65 (9) ◽  
pp. 3996-4001 ◽  
Author(s):  
Yoshitaka Shiomi ◽  
Masaya Nishiyama ◽  
Tomoko Onizuka ◽  
Takuya Marumoto
Keyword(s):  
Bacterial Wilt ◽  
In Vitro Assays ◽  
Gram Negative Bacteria ◽  
16S Rdna Sequence ◽  
Tomato Plants ◽  
16S Rdna Sequence Analysis ◽  
Bacterial Groups ◽  
Chloroform Fumigation ◽  
Tomato Bacterial Wilt

ABSTRACT It has been reported that the growth of Ralstonia solanacearum is suppressed at the rhizoplane of tomato plants and that tomato bacterial wilt is suppressed in plants grown in a soil (Mutsumi) in Japan. To evaluate the biological factors contributing to the suppressiveness of the soil in three treated Mutsumi soils (chloroform fumigated soil; autoclaved soil mixed with intact Mutsumi soil; and autoclaved soil mixed with intact, wilt-conducive Yamadai soil) infested with R. solanacearum, we bioassayed soil samples for tomato bacterial wilt. Chloroform fumigation increased the extent of wilt disease. More of the tomato plant samples wilted when mixed with Yamadai soil than when mixed with Mutsumi soil. Consequently, the results indicate that the naturally existing population of microorganisms in Mutsumi soil was significantly able to reduce the severity of bacterial wilt of tomato plants. To characterize the types of bacteria present at the rhizoplane, we isolated rhizoplane bacteria and classified them into 22 groups by comparing their 16S restriction fragment length polymorphism patterns. In Yamadai soil a single group of bacteria was extremely predominant (73.1%), whereas in Mutsumi soil the distribution of the bacterial groups was much more even. The 16S rDNA sequence analysis of strains of dominant groups suggested that gram-negative bacteria close to the β-proteobacteria were most common at the rhizoplane of the tomato plants. During in vitro assays, rhizoplane bacteria in Mutsumi soil grew more vigorously on pectin, one of the main root exudates of tomato, compared with those in Yamadai soil. Our results imply that it is difficult for the pathogen to dominate in a diversified rhizobacterial community that thrives on pectin.

In vitro evaluation of bio-agents against Pyricularia oryzae (Cav.) causing rice blast disease

2017 ◽  
Vol 37 (03) ◽  
Author(s):  
Akhilesh Kumar Kulmitra ◽  
Neha Sahu ◽  
V.B. Sanath Kumar ◽  
Thejesha A. G. ◽  
Amlan Ghosh ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Pseudomonas Fluorescens ◽  
Rice Blast ◽  
Mycelial Growth ◽  
Trichoderma Viride ◽  
Culture Technique ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Dual Culture

The five different bio-agents viz., Trichoderma viride, T. harzianum, T. virens, Pseudomonas fluorescens and Bacillus subtilis were evaluated against Pyricularia oryzae at four and eight days after incubation through dual culture technique. Among the five different bio-agents, highest per cent inhibition of mycelial growth of fungus was recorded in T. virens i.e. 67 per cent and 70 percent after four and eight days after incubation respectively with mean of 68.5 per cent followed by Trichoderma viride with the inhibition of 61 and 63 per cent respectively with mean of 62 per cent. The Pseudomonas fluorescens did not show any inhibition of mycelial growth of P. oryzae as the pathogen over grew the bio-agents.

scholarly journals KARAKTERISASI BAKTERI DARI PERAKARAN Nepenthes mirabilis UNTUK PENGENDALIAN HAYATI Fusarium oxysporum

2020 ◽  
Vol 31 (1) ◽  
pp. 48
Author(s):  
NFN Mardhiana ◽  
Muh. Adiwena ◽  
Ankardiansyah Pandu Pradana
Keyword(s):  
Fusarium Oxysporum ◽  
Plant Protection ◽  
Physiological Activity ◽  
Physiological Characteristic ◽  
Dual Culture ◽  
Antagonistic Bacteria ◽  
Bacterial Isolates ◽  
Chitinolytic Enzyme ◽  
Physiological Tests

<em>Phytopathogenic fungi </em>Fusarium oxysporum<em> causes significant yield losses in various spices plants. The fungus can be controlled with numerous types of antagonistic bacteria. Th</em><em>is study aimed to determine the physiological characteristic and antagonistic properties of the bacterial from the roots of </em>Nepenthes mirabilis<em>, as a biological control </em><em>to </em>F. oxysforum<em>. The study was conducted at the Plant Protection Laboratory, Faculty of Agriculture, the University of Borneo, Tarakan</em><em>, from October to November 2017. Nutrient Agar medium was used to isolate antagonistic bacteria from the roots of </em>N. mirabilis<em>. Biosafety test against plants and mammals were conducted using hypersensitive and hemolysis </em><em>analysis. The bacterial isolates passed from those tests were characterized further for their phenotype and physiological properties as well as their ability to inhibit the growth of </em>F. oxysporum<em> in a dual culture test  in  vitro.  The  results  showed  that  there  were  10  out  of</em><em>26 bacterial isolates originated from </em>N. mirabilis<em> roots that were safe for plants and mammals. </em><em>Physiological tests showed  that four  isolates  could produce the proteolytic enzyme, five isolates produced the chitinolytic enzyme, six isolates were able to dissolve phosphate, and four isolates could produce HCN. Furthermore, three isolates (Mrb2, Mrb6, and Mrb16) showed inhibitory activity against </em>Fusarium<em> spp. There were differences in the phenotype character and physiological activity between the Mrb2, Mrb6, and Mrb16 isolates, but all three have the potential to inhibit </em>F. oxysporum<em>.</em>

Bioefficacy of rhizospheric fungal isolates against wilt and root-rot pathogens of Pea

2019 ◽  
Vol 5 (01) ◽  
pp. 133-137
Author(s):  
Rashmi S. Nigam ◽  
R. U. Khan ◽  
Reshu Singh ◽  
Joginder Singh
Keyword(s):  
Root Rot ◽  
Pythium Ultimum ◽  
Culture Technique ◽  
Dual Culture ◽  
Yield And Quality ◽  
Fungal Isolates ◽  
Antagonistic Potential ◽  
Production Areas

Pea (Pisum sativum) is an important leguminous crop in many countries including India. Wilt and root rot of pea is an important and widespread disease that often causes significant reduction in the yield and quality of harvested peas throughout the production areas. It is the most important and widespread disease of pea grown in relatively dry and warm area. In-vitro effectiveness of various antagonistic fungal isolates namely T. harzianum (Th1, Th2, Th3, Th4 and Th5) was evaluated against Fusarium oxysporum f. sp. pisi, Rhizoctonia solani and Pythium ultimum by dual culture technique on potato dextrose agar. According to the observation recorded after 5 days, all the rhizospheric fungal isolates evaluated for their antagonistic potential against wilt and root-rot pathogens, exhibited significant effect on radial growth inhibition of pathogens in comparison to control. Among the fungal isolates, Th3 and Th5 of T. harzianum proved to be most effective in reducing the growth of F. oxysporum f. sp. pisi, R. solani and P. ultimum. It was worthy to note that all rhizospheric fungal isolates visualized an increase in their antagonistic potential over the period of time in subsequent hours of inoculation.

scholarly journals In vitro evaluation of grapevine endophytes, epiphytes and sap micro-organisms for potential use to control grapevine trunk disease pathogens

2021 ◽  
Author(s):  
Robert Blundell ◽  
Molly Arreguin ◽  
Akif Eskalen
Keyword(s):  
Biological Control ◽  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Dual Culture ◽  
Biological Control Agents ◽  
In Planta ◽  
Eutypa Dieback ◽  
Fungal Isolates ◽  
Wound Protection

SummaryGrapevine trunk diseases (GTDs) threaten the economic sustainability of viticulture worldwide causing a significant reduction of both yields and quality of grapes. Biological control presents a promising sustainable alternative to cultural and chemical methods to mitigate the effects of pathogens causing GTDs, including Botryosphaeria dieback, Eutypa dieback and Esca. This study aimed to identify naturally occurring potential biological control agents from a variety of grapevine tissues, including sap, cane and pith and evaluate their antagonistic activity against selected fungal pathogens responsible for GTDs in vitro. Bacterial and fungal isolates were preliminary screened in vitro to determine their antifungal activity via a dual culture assay against Neofusicoccum parvum and Eutypa lata. Among the fungal isolates, Trichoderma spp. inhibited E. lata mycelial growth up to 64% and N. parvum mycelial growth up to 73% with overgrowth and stopped growth being the likely antagonistic mechanisms. Among the bacterial isolates, Bacillus spp. inhibited E. lata mycelial growth up to 20% and N. parvum mycelial growth up to 40%. Select antagonistic isolates of Trichoderma, Bacillus and Aureobasidium spp. were subject to further dual culture antifungal analysis against Diplodia seriata and Diaporthe ampelina, with Trichoderma isolates consistently causing the greatest inhibition. Volatile organic compound antifungal analysis revealed that these Trichoderma isolates resulted significantly inhibited mycelial growth of N. parvum, E. lata and D. ampelina causing up to 20.11%, 60.55% and 70.9% inhibition respectively (P≤0.05). Multilocus sequence analysis revealed that the Trichoderma isolates are most closely related to Trichoderma asperellum and Trichoderma hamatum. This study identifies grapevine sap as a novel source of potential biological control agents for control of GTDs to support existing efforts to control GTDs. Further testing will be necessary to fully characterize these microbes mode of antagonism and assess their efficacy for pruning wound protection in planta.

scholarly journals Evaluation of Plant Origin Essential Oils as Herbal Biocides for the Protection of Caves Belonging to Natural and Cultural Heritage Sites

2021 ◽  
Vol 9 (9) ◽  
pp. 1836
Author(s):  
Anthoula A. Argyri ◽  
Agapi I. Doulgeraki ◽  
Eftychia G. Varla ◽  
Vasiliki C. Bikouli ◽  
Pantelis I. Natskoulis ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Essential Oils ◽  
Inhibitory Concentration ◽  
Plant Origin ◽  
Bacterial Isolates ◽  
Origanum Vulgare ◽  
Heritage Sites ◽  
Fungal Isolates ◽  
Satureja Thymbra

The present study concerns the serious issue of biodeterioration of the caves belonging to natural and cultural heritage sites due to the development of various microorganisms. Thus, a series of 18 essential oils (EOs) extracted from various Greek plants were evaluated in vitro (concentrations of 0.1, 0.2, 0.5, 1.0 and 5.0% v/v) against 35 bacterial and 31 fungi isolates (isolated from a Greek cave) and the antimicrobial activity was evident through the changes in optical density of microbial suspensions. In continuance, eight (8) representative bacterial and fungal isolates were further used to evaluate the minimum inhibitory concentration (MIC) and non-inhibitory concentration (NIC) values of the most effective EOs. According to the results, two EOs of Origanum vulgare were the most effective by inhibiting the growth of all the tested microorganisms at 0.1% (v/v), followed by that of Satureja thymbra which inhibited all bacterial isolates at 0.1% (v/v) and fungal isolates at 0.1, 0.2 and 0.5% (v/v) (depending on the isolate). The MIC ranged between 0.015–0.157 and 0.013–0.156 (v/v) for the bacterial and fungal isolates respectively, depending on the case. The current study demonstrated that conventional biocides may be replaced by herbal biocides with significant prospects for commercial exploitation.

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