THE INTERACTIONS OF TRICHODERMA HAMATUM, PYTHIUM APHANIDERMATUM, AND CUCUMIS SATIVUS AS INFLUENCED BY CARBON DIOXIDE AND OXYGEN CONCENTRATIONS (CONTROLLED ATMOSPHERES, BIOLOGICAL CONTROL, SOIL ATMOSPHERES). Item Type text; Thesis-Reproduction (electronic) Authors Mauk, Peggy Ann. 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. Download date 28/09/2021 18:22:50 Link to Item http://hdl.handle.net/10150/275388 INFORMATION TO USERS This reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. 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Zeeb Road Ann Arbor, Ml 48106 1326385 Mauk, Peggy Ann THE INTERACTIONS OF TRICHODERMA HAMATUM, PYTHIUM APHANIDERMATUM, AND CUCUMIS SATIVUS AS INFLUENCED BY CARBON DIOXIDE AND OXYGEN CONCENTRATIONS The University of Arizona M.S. 1985 University Microfilms International 300 N. Zeeb Road, Ann Arbor, Ml 48106 PLEASE NOTE: In all cases this material has been filmed in the best possible way from the available copy. Problems encountered with this document have been identified here with a check mark V . 1. Glossy photographs or pages \/ 2. Colored illustrations, paper or print 3. Photographs with dark background v/ 4. Illustrations are poor copy 5. Pages with black marks, not original copy 6. Print shows through as there is text on both sides of page 7. Indistinct, broken or small print on several pages 8. Print exceeds margin requirements 9. Tightly bound copy with print lost in spine 10. Computer printout pages with indistinct print 11. Page(s) lacking when material received, and not available from school or author. 12. Page(s) seem to be missing in numbering only as text follows. 13. Two pages numbered . Text follows. 14. Curling and wrinkled pages 15. Dissertation contains pages with print at a slant, filmed as received 16. Other University Microfilms International THE INTERACTIONS OF TRICHODERMA HAMATUM. PYTHIUM APHANIHFRMATIIM. AND CUCUMIS SAT I VUS AS INFLUENCED BY CARBON DIOXIDE AND OXYGEN CONCENTRATIONS by Peggy Ann Mauk A Thesis Submitted to the Faculty of The DEPARTMENT OF PLANT PATHOLOGY In Partial Fulfillment of the Requirements For the Degree of MASTERS OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 19 8 5 STATEMENT BY AUTHOR This thesis has been submitted In partial fuflllment of requirements for an advanced degree at The University of Arizona and Is deposited In the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable with out special premlsslon, provided that accurate acknowledgement of source Is made. Requests for permission for extended quotation from or reproduction of this manuscript In whole or In part may be granted by the head of the major department on the Dean of the Graduate College when In his or her judgement the proposed use of the material Is In the Interests of scholarship. In all other Instances, however, permission must be obtained from the author. SIGNED APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: <K J. MISAGHI ^ Department of Plant Pathology ACKNOWLEDGEMENTS I wou I d I Ike to thank Dr. I raj MIsagh I for h Is cont Inued help, encouragement, and advice through-out the course of my research, I wouId also I Ike to thank Mr. Pat Paschal for bulIdlng the gas mixing system and for help with the gas chromatograph; Dr. Mary 01sen for her advIce In system desIgn; Dr. Mike Stanghelllnl for his technlea I and critical advice; Dr. J. P. LIndsey for her encouragement; and Mr. Jim Adaskaveg for his encouragement and support through-out the course of my work. I like to thank the Graduate College of the University of Arizona for their financial award which helped me to purchase necessary laboratory equipment. Ill TABLE OF CONTENTS Page LIST OF TABLES v LIST OF ILLUSTRATIONS vl 1. INTRODUCTION 1 2. MATERIALS AND METHODS 5 Mixing and delivery of gases 5 Controlled atmosphere treatment system and gas analysis . 5 Selection of the antagonist and the pathogen 6 Microscopic evaluation of the parasitic activity of I. hamatum on £. aphan f dermatum 6 Pathogenicity of P.aphanIdermatum on cucumber and antagonist ability of J. hamatum 7 Effect of CA on linear growth of E. aphanldermatum and I. hamatum 8 The effect of CA on propagule production by E. aphanldermatum and I. hanatum 9 Effect of CA on Interactions among E* aphanldermatum. X. hamatum. and cucumber 10 3. RESULTS M Parasitic activity of I. hamatum on E. aphanldermatum. 14 Interactions of E. aphanldermatum. cucumber and X. hamatum 14 The effect of CA on linear growth 16 The effect of CA on propagule production 16 Effect of CA on Interactions among E. aphanldermatum Ihamatum and cucumber ..... 20 4. DISCUSSION 24 5. LITERATURE CITED 28 LIST OF TABLES Page 1. Effect of controlled atmospheres on the linear growth of Pyth1um aphanldermatum (Pa-1) and Trlchoderma hamatum (Co 1215) on 5% V8 juice agar 17 2. Effectof control led atmospheres on oospore and sporangia production by Pyth1um aphanidermatum In the presence and absence of Trlchoderma ha^tum 18 3. Propagule production by Pvth1um aphanIdermatum In the presence and absence of Trlchoderma hamatum under 5 C02/02 concentrations 19 4. Effect of controlled atmospheres on the Interactions between PythIum aphanIdermatum and Trlchoderma hamatum on cucumber. 23 v LIST OF ILLUSTRATIONS Figure t. Apparatus for the exposure of germinating seeds under controlled atmospheres 11 2. Progression of parasitic activity of Tclchoderma hamatum on PythIum aphanIdermatum on water agar 15 3. Effect of control led atmospheres on oospore production by Pyth1um aphanldermatum Isolates, Pa-1 and PaERL-9, In the presence of 2 Isolates of Trlchoderma hamatum (Co 1215 and ss1215-4) 21 4. Effect of gas composition on propagule production by TrIchoderma hamatum 22 vl ABSTRACT Pyth1um aphanldermatum and an antagonist, Trlchoderma hamatum. were grown Individual ly and col lectlvely on 5% V8 agar at 27 C In the dark under the following percentages of C02/02: 0.03/20.9, 1/20, 4/17, 7/14, and 10/11. Oospore and sporangia production by E. aphanldermatum was suppressed under C02/02 concentrations of 1/20, 4/17, 7/14, and 10/11 compared to ambient air (0.03/20.9). The C02-!nduced suppression was more pronounced when Pythlum was cocultured with I. hamatum Isolate, ss1215-4. In contrast, I. hamatum Isolate, Co 1215 partially counteracted the C02-lnduced suppression. Contdla production by I. hamatum Increased by 45$ when under C02/ 02 levels of 1/20. Chlamydospore production was not affected by changes In C02/02 levels. Changes In the levels of C02 and 02 did not affect disease Incidence caused by PYthlum aphanldermatum on cucumber seeds. L hamatum almost completely protected cucumber seeds from Pyth1um at the ambient atmosphere while providing no protection at C02/02 levels of 4/17. vll INTRODUCTION Biological control of plant pathogens Is an attractive alternative to chemical control. However, at the present time, the successful use of blocontrol agents (bacteria and fungi) In greenhouse situations far exceeds field application. The major drawback Is the Inability of antagonists to become established In the soil ecosystem (Cook and Baker 1983). Researchers have found various methods of applying fungal antagonists to the soil. These methods Involve culturlng of fungi In wheat-bran culture (Hadar, Chet, and Henls 1979), or mixing cultures grown In molasses with dlatomaceous earth as a carrier (Bachman and RodrIguez-Kabana 1975) In hopes of favoring their establishment In the soil. These methods, for the most part, have been unsuccessful. Several species of TrIchoderma. a known fungal antagonist, have shown potential for use as blocontrol agents. However, field success has been Inconsistent.