Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1980 Inheritance of Brown Leaf Spot of Rice Caused by Cochliobolus Miyabeanus and Varietal Reaction to Isolates of This Fungus. Peter Godwin Eruotor Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Eruotor, Peter Godwin, "Inheritance of Brown Leaf Spot of Rice Caused by Cochliobolus Miyabeanus and Varietal Reaction to Isolates of This Fungus." (1980). LSU Historical Dissertations and Theses. 3477. https://digitalcommons.lsu.edu/gradschool_disstheses/3477 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or “target” for pages apparently lacking from the document photographed is “Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or duplicate copy. Unless we meant to delete copyrighted materials that should not have been filmed, you will find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., is part of the material being photo­ graphed the photographer has followed a definite method in “sectioning” the material. It is customary to begin filming at the upper left hand comer of a large sheet and to continue from left to right in equal sections with small overlaps. If necessary, sectioning is continued again—beginning below the first row and continuing on until complete. 4. For any illustrations that cannot be reproduced satisfactorily by xerography, photographic prints can be purchased at additional cost and tipped into your xerographic copy. Requests can be made to our Dissertations Customer Services Department. 5. Some pages in any document may have indistinct print. In all cases we have filmed the best available copy. University/ M icrofilm s International 300 N. ZEEB ROAD, ANN ARBOR. Ml 48106 18 BEDFORD ROW, LONDON WC1 R 4EJ. ENGLAND 8021739 ERUOTOR, PETER GODWIN INHERITANCE OF BROWN LEAF SPOT OF RICE CAUSED BY COCHLIOBOLUS MIYABEANUS AND VARIETAL REACTION TO ISOLATES OF THIS FUNGUS The Louisiana State University and Agricultural and Mechanical Col. PH.D. 1980 University Microfilms International300 N. Zeeb Road, Ann Arbor, MI 48106 18 Bedford Row, London WC1R 4EJ, England Copyright i9so by ERUOTOR, PETER GODWIN All Rights Reserved 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 . 1. Glossy photographs 2. Colored illustrations____ 3. Photographs with dark background ^ '4. Illustrations are poor copy ______ 5. °rint shows through as there is text on both sides of page _______ 6. Indistinct, broken or small print on several pages _________ throughout 7. Tightly bound copy with print lost in spine ______ 8. Computer printout pages with indistinct print ______ 9. Page(s) ____ lacking when material received, and not available from school or author ______ 10. Page(s) ______ seem to be missing in numbering only as text fo11ows ______ 11. Poor carbon copy ______ 12. Not original copy, several pages with blurred type _ 13. Appendix pages are poor copy ______ 14. Original copy with light type _______ 15. Curling and wrinkled pages ______ 16. Other University Microfiims International 300 .\ Z=== »D. AMN A 3 3 0 S VII JS '06 -312! 761-4700 INHERITANCE OF BROWN LEAF SPOT OF RICE CAUSED BY COCHLIOBOLUS MIYABEANUS AND VARIETAL REACTION TO ISOLATES OF THIS FUNGUS A DISSERTATION Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Agronomy by Peter Godwin Eruotor B. S., Ahmadu Bello University, 1972 M. S., Texas A. & M. University, 1977 May 1980 ACKNOWLEDGEMENTS The author wishes to express his sincere appreci­ ation to Dr. B. J. Hoff, for his guidance in organ­ izing the study and in the preparation of the dissertation. He is grateful for his advice, encouragement, friendship and patience throughout the course of this study. Sincere appreciation is extended to Dr. M. C. Rush for helpful suggestions and assistance with the pathology aspects of this study. Special appreciation is expressed to other members of his committee: Drs. M. T. Henderson, P. E. Schilling, J. E. Jones, W. O. Mcllrath, and W. B. Birchfield who advised and encouraged him throughout the investigation and for their comments and cooperation in reviewing this dissertation. He is grateful to Dr. K. L. Koonce for assistance in the sta­ tistical analyses and interpretation of the data. Thanks are also extended to Dr. W. H. Willis, former Head, Department of Agronomy, Louisiana State University, Mr. M. D. Faulkner, Superintendent, Louisiana State University Rice Ex­ periment Station, Crowley and to Dr.W. J. Martin, head, Depart­ ment of Plant Pathology, for providing the necessary facili­ ties for this study. Sincere thanks are extended to the government of the Fed­ eral Republic of Nigeria for granting the fellowship which enabled him to complete his graduate studies, and to the National Cereals Research Institute for granting study leave. ii Deep and heart-felt appreciation is extended to his wife, Christiana and his sons Mudiaga Christopher, Ogheneochuko Jerome and Emuesiri Jude, for their love, patience, understand­ ing and encouragement throughout the course of this study. Further acknowledgement is extended to Ms. Susan Besse for her efforts in typing this manuscript. Finally, he dedicates this dissertation to the memories of his late father and father-in-law Chief Kosin Erheruvwereyo Eruotor and Chief Johnson Gbosien Sokoh, respectively. iii TABLE OF CONTENTS PAGE ACKNOWLEDGEMENTS .......................................... li LIST OF TABLES ............................................. v LIST OF FIGURES ............................................. x ABSTRACT ................................................... INTRODUCTION ............................................... ! REVIEW OF LITERATURE ...................................... 3 MATERIALS AND METHODS ...................................... 20 Origin of Test Isolates ................................20 Isolation of Cultures ............................... 21 Selection of Test V a r i e t i e s ........................... 26 Inoculation of Test Varieties ......................... 29 Comparative Study of Six Isolates of Cochliobolus miyabeanus 3 5 Inheritance of an Atypical Brown Leaf Spot of C. miyabeanus and of Leaf Sheath Color 3 6 RESULTS AND DISCUSSION ........................ 41 Studies on 29 Isolates of Cochliobolus miyabeanus. 41 Comparative Study of Six Isolates of Cochliobolus miyabeanus .........................................64 Morphological differences in Conidia ................. 84 Inheritance of Resistance to Cochliobolus m i y a b e a n u s ............................................. 94 Inheritance of Leaf Sheath Color .................... 13 2 SUMMARY ....................................................... 139 SELECTED BIBLIOGRAPHY ...................................... 146 APPENDIX ..................................................... 153 VITA ......................................................... IPS iv LIST OF TABLES TABLE PAGE 1. COMPARISONS OF CONIDIAL MEASUREMENTS OF C. MIYA­ BEANUS AS REPORTED BY DIFFERENT AUTHORS ............ 12 2. SOURCES OF THE ISOLATES USED IN THIS STUDY.......... 22 3. DISEASE REACTIONS AND DAYS TO HEAD OF SELECTED VARIETIES AND LINES IN THE 197 6 DISEASE NURSERY . 27 4. RATING SYSTEM FOR DETERMINING RESISTANCE TO COCHLIOBOLUS MIYABEANUS .............................. 33 5. AVERAGE LESION SIZE FOR 12 TEST VARIETIES INOCULATED WITH 23 ISOLATES OF COCHLIOBOLUS MIYABEANUS.............................................. 45 6 . AVERAGE RATING FOR LESION SIZE FOR 12 TEST VARIETIES INOCULATED WITH 29 ISOLATES OF COCHLIOBOLUS m i y a b e a n u s ......................... “ r -: : : T . 50 7. AVERAGE LESION NUMBER ON 12 TEST VARIETIES . INOCULATED WITH 23 ISOLATES OF COCHLIOBOLUS MIYABEANUS.................. ........................... 53 8 . AVERAGE RATING FOR LESION NUMBER ON 12 TEST VARIE­ TIES INOCULATED WITH 29 ISOLATES OF COCHLIOBOLUS MIYABEANUS ......................... ................ 55 9. AVERAGE DISEASE RATING FOR 12 TEST VARIETIES INOCULATED WITH 29 ISOLATFS OF COCHLIOBOLUS MIYABEANUS.............................................. 58 10. AVERAGE MAXIMUM AND MINIMUM TEMPERATURE IN