FACTORS AFFECTING VIABILITY OF STRANDS OF PHYMATOTRICHUM OMNIVORUM (SHEAR) DUGGAR.

Persistent Link:
http://hdl.handle.net/10150/185881
Title:
FACTORS AFFECTING VIABILITY OF STRANDS OF PHYMATOTRICHUM OMNIVORUM (SHEAR) DUGGAR.
Author:
ABDUL SATTAR, MUSTAFA HASSAN.
Issue Date:
1983
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Declining infestations and the cyclic appearance of Phymatotrichum root rot of cotton from season to season led to the suggestion that antagonistic microorganisms were the cause of this phenomenon. This study was concerned primarily with Actinomycetes spp., fluorescent Pseudomonads, Trichoderma spp., and other fungi. There was a continuous fluctuation in the population of Actinomycetes spp. and fluorescent Pseudomonads on the surface of strands. Populations of these antagonistic organisms dropped as the viability of strands of P. omnivorum decline. Comparison of the rhizoplane microflora from infected and healthy roots showed no relationship between the populations of Actinomycetes spp. and fluorescent Pseudomonads and the resistance of healthy roots to invasion by P. omnivorum. Similarly, soil samples collected from areas with declining infestations and assayed for populations of Actinomycetes spp. and fluorescent Pseudomonads, revealed no differences in the populations of these antagonistic organisms. This indicates that the absence of the disease in areas with declining infestations is not due to the microorganisms investigated in this study. Higher mortality rates of strands of P. omnivorum occurred when strands were exposed to Actinomycetes spp. and fluorescent Pseudomonads or to their metabolites. The hyphal deformation observed on strands from the field could not be reproduced in vitro. The same antagonistic microorganisms sprayed on cotton roots containing strands failed to reduce strand viability.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Cotton root rot.; Soil microbiology -- Arizona -- Marana Region.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Plant Pathology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Hine, Richard B.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleFACTORS AFFECTING VIABILITY OF STRANDS OF PHYMATOTRICHUM OMNIVORUM (SHEAR) DUGGAR.en_US
dc.creatorABDUL SATTAR, MUSTAFA HASSAN.en_US
dc.contributor.authorABDUL SATTAR, MUSTAFA HASSAN.en_US
dc.date.issued1983en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractDeclining infestations and the cyclic appearance of Phymatotrichum root rot of cotton from season to season led to the suggestion that antagonistic microorganisms were the cause of this phenomenon. This study was concerned primarily with Actinomycetes spp., fluorescent Pseudomonads, Trichoderma spp., and other fungi. There was a continuous fluctuation in the population of Actinomycetes spp. and fluorescent Pseudomonads on the surface of strands. Populations of these antagonistic organisms dropped as the viability of strands of P. omnivorum decline. Comparison of the rhizoplane microflora from infected and healthy roots showed no relationship between the populations of Actinomycetes spp. and fluorescent Pseudomonads and the resistance of healthy roots to invasion by P. omnivorum. Similarly, soil samples collected from areas with declining infestations and assayed for populations of Actinomycetes spp. and fluorescent Pseudomonads, revealed no differences in the populations of these antagonistic organisms. This indicates that the absence of the disease in areas with declining infestations is not due to the microorganisms investigated in this study. Higher mortality rates of strands of P. omnivorum occurred when strands were exposed to Actinomycetes spp. and fluorescent Pseudomonads or to their metabolites. The hyphal deformation observed on strands from the field could not be reproduced in vitro. The same antagonistic microorganisms sprayed on cotton roots containing strands failed to reduce strand viability.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectCotton root rot.en_US
dc.subjectSoil microbiology -- Arizona -- Marana Region.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePlant Pathologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorHine, Richard B.en_US
dc.contributor.committeememberStanghellini, M. E.en_US
dc.contributor.committeememberGilbertson, R. L.en_US
dc.contributor.committeememberMisaghi, I. J.en_US
dc.contributor.committeememberMcClure, M. A.en_US
dc.identifier.proquest8315269en_US
dc.identifier.oclc688635458en_US
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