Evaluation of direct antagonism by phylloplane bacteria, and induced systemic resistance by piriformospora indica on the suppression of foliar blight disease of amaranthus (Amaranthus tricolor L.)
By: Gayathri Nair.
Contributor(s): Anitha, K N (Guide).
Material type:
BookPublisher: Vellayani Department of Plant Biotechnology, College of Agriculture 2017Description: 67p.Subject(s): Biotechnology | Plant BiotechnologyDDC classification: 660.6 Online resources: Click here to access online Dissertation note: BSc-MSc (Integrated) Abstract: The study entitled “Evaluation of direct antagonism by phylloplane bacteria,
and induced systemic resistance by Piriformospora indica on the suppression of
foliar blight disease of amaranthus (Amaranthus tricolor L.)” was carried out at the
Department of Agricultural Microbiology and Department of Plant Biotechnology,
College of Agriculture, Vellayani, Trivandrum.
The study was mainly focused on evaluating the potential of a combination of
the root colonizing fungus Piriformospora indica and bacterial isolates from
amaranthus (var. Arun) phyllosphere in suppressing the foliar blight disease by the
pathogen Rhizoctonia solani. The pathogen was isolated from the amaranthus fields
of College of Agriculture, Vellayani. Pathogenicity testing of R. solani revealed that
it could infect the detached leaves of healthy amaranthus plants with and without
giving a pin prick on the detached leaves. Two phylloplane isolates isolated on the
various concentrations of agar showed inhibition in the mycelial growth of R. solani
upon dual culture plate assay and were identified as Bacillus velezensis and
Roseomonas gillardi upon molecular characterization. P. indica did not show any
direct antagonism against the R. solani.
Effective colonization by the P. indica was established and confirmed by
various staining procedures like trypan blue staining and WGA-AF 488 staining and
confocal microscopy and confirmed by DNA isolation and PCR. Prominent
colonization was found in amaranthus plants cocultured with P. indica in artificial
media like PDA, MS and PDA-MS.
The results of the in vivo field experiments, showed that P. indica could
increase the plant growth parameters like shoot length, number of leaves, fresh and
dry weight of shoot and roots. Since amaranthus is one of the widely used leafy
vegetable in the market, its commercial production can be effected if the vegetative
growth parameter, are increased in production. It was also observed that the
endophytic fungus P. indica as well as a combination of both the fungus along with
the phylloplane isolate Bacillus velezensis could reduce the disease incidence by
84.13% and 63.84% compared to the control on the first day of symptom incidence
which might favour the amaranth growers especially in the monsoon in tackling the
blight. It was also seen that P. indica colonized treatments showed elevated defense
enzyme levels like phenyl alanine ammonia lyase, peroxidase and poly phenol
oxidase after inoculation with the pathogen Rhizoctonia solani.
| Item type | Current location | Collection | Call number | Status | Date due | Barcode |
|---|---|---|---|---|---|---|
Theses
|
KAU Central Library, Thrissur Theses | Reference Book | 660.6 GAY/EV (Browse shelf) | Not For Loan | 174181 |
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BSc-MSc (Integrated)
The study entitled “Evaluation of direct antagonism by phylloplane bacteria,
and induced systemic resistance by Piriformospora indica on the suppression of
foliar blight disease of amaranthus (Amaranthus tricolor L.)” was carried out at the
Department of Agricultural Microbiology and Department of Plant Biotechnology,
College of Agriculture, Vellayani, Trivandrum.
The study was mainly focused on evaluating the potential of a combination of
the root colonizing fungus Piriformospora indica and bacterial isolates from
amaranthus (var. Arun) phyllosphere in suppressing the foliar blight disease by the
pathogen Rhizoctonia solani. The pathogen was isolated from the amaranthus fields
of College of Agriculture, Vellayani. Pathogenicity testing of R. solani revealed that
it could infect the detached leaves of healthy amaranthus plants with and without
giving a pin prick on the detached leaves. Two phylloplane isolates isolated on the
various concentrations of agar showed inhibition in the mycelial growth of R. solani
upon dual culture plate assay and were identified as Bacillus velezensis and
Roseomonas gillardi upon molecular characterization. P. indica did not show any
direct antagonism against the R. solani.
Effective colonization by the P. indica was established and confirmed by
various staining procedures like trypan blue staining and WGA-AF 488 staining and
confocal microscopy and confirmed by DNA isolation and PCR. Prominent
colonization was found in amaranthus plants cocultured with P. indica in artificial
media like PDA, MS and PDA-MS.
The results of the in vivo field experiments, showed that P. indica could
increase the plant growth parameters like shoot length, number of leaves, fresh and
dry weight of shoot and roots. Since amaranthus is one of the widely used leafy
vegetable in the market, its commercial production can be effected if the vegetative
growth parameter, are increased in production. It was also observed that the
endophytic fungus P. indica as well as a combination of both the fungus along with
the phylloplane isolate Bacillus velezensis could reduce the disease incidence by
84.13% and 63.84% compared to the control on the first day of symptom incidence
which might favour the amaranth growers especially in the monsoon in tackling the
blight. It was also seen that P. indica colonized treatments showed elevated defense
enzyme levels like phenyl alanine ammonia lyase, peroxidase and poly phenol
oxidase after inoculation with the pathogen Rhizoctonia solani.
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