scholarly journals Affectivity evaluation of Bacillus subtilis in controlling eggplant root rot caused by Rhizoctonia solani and Fusarium solani

Author(s):  
Q. H. Madhi ◽  
A. M. Jumaah
2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Manzoor R. Khan ◽  
Zaki A. Siddiqui

AbstractEffects of Pseudomonas putida and Bacillus subtilis alone, and in combinations for the management of Meloidogyne incognita, Pectobacterium betavasculorum, and Rhizoctonia solani disease complex of beetroot (Beta vulgaris L.), were studied. Application of P. putida or B. subtilis to plants with M. incognita or P. betavasculorum or R. solani singly or in combinations caused a significant increase in plant growth parameters and the activities of defense enzymes. A significant increase in chlorophyll fluorescence attributes, viz., Fv/Fm, ɸPSII, qP, NPQ, and ETR were recorded in plants treated with P. putida or B. subtilis over pathogen-inoculated plants. Inoculation of P. putida results in a higher reduction in galling and nematode multiplication than B. subtilis. Maximum reduction in nematode multiplication and galling occurred when a mixture of P. putida and B. subtilis was used. Soft rot and root rot indices were 3 when Pectobacterium betavasculorum and Rhizoctonia solani were inoculated alone. The disease indices were rated 5 when these pathogens and M. incognita were inoculated in combinations. Inoculation of P. putida/B. subtilis with P. betavasculorum or R. solani reduced soft rot and root rot indices to 2 out of 3, while the use of P. putida + B. subtilis reduced indices to 1. Disease indices were reduced to 2–3 out of 5, when P. putida + B. subtilis were used to plants inoculated with two or three pathogens. The principal component analysis showed significant correlations among the various studied attributes. Two principal components explained a total of 86.1 and 93.4% of the overall data variability. Therefore, the use of P. putida together with B. subtilis had the potential for successful management of disease complex of beetroot.


1993 ◽  
Vol 73 (1) ◽  
pp. 365-367 ◽  
Author(s):  
J. C. Tu ◽  
S. J. Park

A bean (Phaseolus vulgaris) line, A - 300, resistant to Rhizoctonia solani and Fusarium oxysporum was introduced into Ontario from Colombia. The results of tests conducted in a root-rot nursery, in a greenhouse and in a growth room showed that this bean line is resistant to Fusarium solani f. sp. phaseoli and Pythium ultimum. Key words: Bean, Phaseolus vulgaris, root rot resistance


2017 ◽  
Vol 14 (1) ◽  
pp. 59 ◽  
Author(s):  
Bruno Sérgio Vieira ◽  
Hyann Markos Pereira Vieira ◽  
Luciana Alves de Sousa ◽  
Karoline Damasceno Ribeiro de Mendonça

<p>Durante uma seleção de bactérias antagonistas realizada no Laboratório de Microbiologia e Fitopatologia da UFU, o isolado de <em>Bacillus subtilis</em>, BSV – 05 se destacou. Diante disso, objetivou-se no presente trabalho avaliar o potencial antagonístico <em>in vitro</em> deste isolado bacteriano contra quatro patógenos radiculares do feijoeiro: <em>Fusarium solani </em>f. sp. <em>phaseoli, Fusarium oxysporum</em> f. sp. <em>phaseoli, Macrophomina phaseolina </em>e <em>Rhizoctonia solani</em>. Foram utilizadas as seguintes metodologias <em>in vitro </em>versus os patógenos citados:<em> </em>cultivo pareado, influência da inoculação conjunta, produção de metabolitos voláteis e não voláteis. Os percentuais de inibição do isolado BSV – 05 sobre <em>M. phaseolina, R. solani, F. solani,</em> <em>F. oxysporum</em>, foram de 61,43%; 50,36%; 13,74% e 7,7%, respectivamente, para a metodologia do cultivo pareado. O contato direto da bactéria com os patógenos inibiu em 100% o crescimento micelial de <em>M. phaseolina, R. solani</em>; e para <em>F. solani </em>e <em>F. oxysporum</em>, foram observadas inibições de 90 e 92 %, respectivamente. Possíveis metabólitos secretados pelo isolado BSV 05 apresentaram níveis de inibição de 100% para <em>R. solani</em>. Para <em>M. phaseolina</em>, observou-se uma porcentagem de inibição de 80,26%, e 45,31% e 47,80% para <em>F. solani </em>e <em>F. oxysporum</em>, respectivamente. A porcentagem de inibição da germinação de conídios de <em>F. solani </em>e <em>F. oxysporum </em>e<em> M. phaseolina</em> num meio de cultura contendo substâncias metabolizadas por BSV – 05 foi de 87,70; 91,28% e 100%, respectivamente. O isolado bacteriano BSV-05 não apresentou produzir nenhum metabólito volátil.</p>


2019 ◽  
Vol 45 (4) ◽  
pp. 355-360
Author(s):  
Maria Alice Formiga Porto ◽  
Márcia Michelle de Queiroz Ambrósio ◽  
Selma Rogéria de Carvalho Nascimento ◽  
Beatriz Letícia Silva da Cruz ◽  
Taffarel Melo Torres

ABSTRACT Root diseases represent one of the main reasons for yield loss in melon crops, especially root and stem rots caused by pathogens like the fungi Fusarium solani (Fs), Macrophomina phaseolina (Mp) and Rhizoctonia solani (Rs), frequently observed in muskmelon either alone or in combination. The objective of this study was to evaluate the effect of the interaction between the pathogens Fs, Mp and Rs on the incidence and severity of root rot and muskmelon development. Two greenhouse experiments were performed using plastic pots with substrate infested with each pathogenic agent alone or in combination. The second experiment was conducted in the same pots that were used in the first experiment. In the first experiment, the disease incidence was higher for the treatment with Fs alone. In the second experiment, the disease incidence and severity were greater for treatment Fs + Rs than for Fs alone. Macrophomina phaseolina was the most commonly isolated pathogen when applied to the plants in a paired mixed inoculum (Fs + Mp and Mp + Rs) in the first experiment. In the second experiment, Fs was more prevalent than the other studied pathogens. Soil infested with Fs had the lowest fresh weight of muskmelon. The pathogens Fs and Mp were more competitive than Rs.


2016 ◽  
Vol 30 (2) ◽  
pp. 109 ◽  
Author(s):  
Ashwini Narasimhan ◽  
Srividya Shivakumar

The chilli crop suffers massive yield loss due to root rot caused by <em>Rhizoctonia solani</em>. An increase of 10 × 10<sup>5</sup> root colonizing units/cm was obtained as a result of <em>Bacillus subtilis</em> in vitro root colonisation assay post germination. Shelf life studies of the formulations revealed stable population level of the biocontrol agent upto 180<sup>th</sup> day (30°C - 1.6 × 10<sup>8</sup>; 4°C - 1.9 × 10<sup>8</sup>) in talc and upto 150<sup>th</sup> day in lignite (30°C - 1.5 × 10<sup>8</sup>; 4°C - 1.3 × 10<sup>8</sup>). Soil, seed, foliar spray and dip treatment methods of <em>B. subtilis</em> and chlorothalonil brought about a considerable enhancement of all biometric parameters and reduced disease incidence compared to the untreated control. In comparison to the untreated control (50 g and 21 g fresh and dry weight, respectively), highest plant fresh weight (76.84 g) and dry weight (34.17 g) was achieved by the Seed application method. Comparison of plant height revealed maximum values 70 cm (soil application) and 77 cm (dip treatment) with <em>B. subtilis</em> application which was analogous to chlorothalonil treatment (56.5 cm with soil application and 70.33 cm with dip treatment) which was considerably superior to the untreated control (58.2 cm with dip treatment and 61 cm with soil application, respectively). Root dip treatment showed considerable increase in root length with <em>B. subtilis</em> (33 cm) and chlorothalonil (28.5 cm) when compared to untreated control (15 cm). Growth promotion was better with Root dip application while disease control was achieved better with seed application. A 66% and 84% reduction in incitation of disease was noticed with soil and seed application methods, respectively.


1994 ◽  
Vol 40 (2) ◽  
pp. 113-119 ◽  
Author(s):  
M. S. Reddy ◽  
R. K. Hynes ◽  
G. Lazarovits

One hundred and twenty diverse bacterial strains were screened under greenhouse conditions for their ability to protect white bean seedlings from preemergence damping-off caused by Pythium ultimum and Rhizoctonia solani and postemergence root rot by Fusarium solani f.sp. phaseoli. Preemergence mortality or root rot increased with an increase in the inoculum concentration of fungal isolates. For further testing, 200 propagules/g soil of P. ultimum, 3 propagules/g soil of R. solani, and log 3 conidia/g vermiculite of F. solani f.sp. phaseoli were used, as these rates provided an optimal level (approximately 50%) of disease severity. Bacterial strains suspended in sterile distilled water were added to pathogen-amended soil or vermiculite at log 7 colony-forming units/g soil or vermiculite prior to seeding. Final healthy stand and root rot were recorded 4 weeks after planting. Nine bacterial strains on P. ultimum, five on R. solani, and nine on F. solani f.sp. phaseoli provided significant (P = 0.05) suppression of disease severity compared with the nonbacterized control. Bacterial strains were also tested in vitro against the mycelial growth of the fungi on solid and liquid media. There was no relationship between the ability of bacterial strains to inhibit fungal vegetative growth on solid culture media and their ability to suppress pathogen activity in the greenhouse, but, for a few strains, the reduction in disease was linked to reduced growth of the pathogens in liquid media.Key words: White bean, damping-off, root rot, Pythium ultimum, Rhizoctonia solani, Fusarium solani f.sp. phaseoli.


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