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Evaluating Alien Germplasm for the Improvement of Maize Hybrids

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Evaluating Alien Germplasm for the Improvement of Maize Hybrids University of Massachusetts Amherst ScholarWorks@UMass Amherst Doctoral Dissertations 1896 - February 2014 1-1-1982 Evaluating alien germplasm for the improvement of maize hybrids. Joel Ivan Cohen University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/dissertations_1 Recommended Citation Cohen, Joel Ivan, "Evaluating alien germplasm for the improvement of maize hybrids." (1982). Doctoral Dissertations 1896 - February 2014. 6000. https://scholarworks.umass.edu/dissertations_1/6000 This Open Access Dissertation is brought to you for free and open access by ScholarWorks@UMass Amherst. It has been accepted for inclusion in Doctoral Dissertations 1896 - February 2014 by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. EVALUATING ALIEN GERMPLASM FOR THE IMPROVEMENT OF MAIZE HYBRIDS A Dissertation Presented By JOEL IVAN COHEN Submitted to the Graduate School of the University of Massachusetts in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY February 1982 Plant and Soil Sciences Joel Ivan Cohen 1982 c All Rights Reserved SEA/CR Grant No. 701-15-50 11 EVALUATING ALIEN GERMPLASM FOR THE IMPROVEMENT OF MAIZE HYBRIDS A Dissertation Presented By JOEL IVAN COHEN Approved as to style and content by: n f- Dr. Walton C. Galinat, Chairperson of Committee Dr. Allen V. Barker, Department Head Department of Plant and Soil Sciences To the loving memory of my father, Rubin Cohen, Who was always the light at the end of all those cascading years; Who never left my thoughts. And who must somehow know. Because his faith never seemed to leave me. Of this document's final completion. ACKNOWLE DGMENTS Now it has come to writing the acknowledgments, a page I thought of quite often over the past few years, wondering when I would get this far. I am very indebted to a number of people who have each added his or her own very special touch to the completion of this dissertation. Dr. Walton C. Galinat, whose guidance was always present, was the chairperson of my committee. It has been a privilege to work and study with him, and I hope this dissertation makes a significant contribution to his pro¬ gram. My time with Dr. -Galinat has provided me with a unique perspective on the evolution of maize and the evolution of a man's ideology. Dr. Chandra V. Pasupuleti has been a continuous source of help and guidance. This has,included directing my cyto- logical studies, field collection of anthers, and preparing many of the photographs used here. Beyond all of this though, her friendship and generosity will be most remembered. My committee members. Dr. Dave Mulcahy and Dr. Steve Herbert, as well as past-member Dr. David MacKenzie were all helpful wherever possible. I wish to thank a number of people at the Experiment Station in Waltham. Dr. Bill McEnroe was instrumental in getting my electrophoretic work started by providing me with needed equipment, chemicals, and funding when other money had run out. Beyond this. Bill provided a perspec¬ tive on just about everything, which has become of ever increasing value. Jane Mika and Dr. Bill Feder both pro¬ vided help and support in a number of technical areas and were a constant source of feedback. Jo Starbuck's help in data collection was most appreciated. I would like to extend special thanks to my wife, Rosalyn Blogier, who helped with just about everything from making graphs and slides for presentations to harvesting in the field. Finally, I want to thank my friends and my mother and brother who provided a continuous atmosphere of support for my work. They listened and listened, even if they did not understand, as the whole process unfolded. V ABSTRACT This research was designed to investigate the effects of alien germplasm on maize hybrids and to evaluate this material as a potential buffer against problems inherent in phenotypically uniform dent lines. A performance trial was grown in three replications over two years to accomplish the above goals. These trials consisted of three separate groups of maize hybrids each differentiated by the amount and type of alien genes pres¬ ent in their backgrounds. The first group was based on lines containing alien genes only from teosinte which were transferred as a result of repeated backcrossing. These were used in the form of seven isogenic lines of dent in- bred A158. The third group contained these seven intro- gressed teosinte lines as well as an additional extra chromosome derived from Tripsacum which had been transferred to a Havels-Al58 background. The second group was a control and consisted of crossing the Havels-Al58 inbred, without the Tripsacum chromosome, by the A158 teosinte substitution lines. The data collected from these crosses were statisti¬ cally analyzed by utilizing different computer programs. A significant increase in heterosis was seen for two of the hybrids containing the extra Tripsacum chromosome. The VI Havels line containing the Tripsacum germplasm also had the largest general combining ability value. Standard deviations increased almost eighty percent from Group I to Group III, indicating the increased diversity generated as the parental genotypes of the hybrids became more diverse. In addition, a cytological examination for the extra Tripsacum chromosome was performed. This necessitated meiotic studies in both pachytene and diakinesis. This confirmed the transmission of the alien chromosome into the eight hybrids of Group III. Finally, kernel storage proteins were examined via polyacrylamide isoelectric focusing. This provided an additional measure of increased genotypic diversity. Both the inbred Havels line containing the alien chromosome and the hybrids of Group III showed a more complex protein profile than the other testers and the other two groups of hybrids. Vll TABLE OF CONTENTS ACKNOWLEDGMENTS . V LIST OF TABLES. xi LIST OF ILLUSTRATIONS.xii LIST OF APPENDIX TABLES.xiii Chapter I. INTRODUCTION . 1 Preface . .. 1 Taxonomic Considerations . 3 Biosystematic Approaches . 8 Gene Flow and Genetic Exchange.14 Introgression . 14 Recombination ..19 Evolutionary Considerations . 21 II. LITERATURE REVIEW . 25 Heterosis.25 Introduction and theories . 25 Recent topics of discussion . 29 Techniques for Genome Modification . 32 Wide crosses.22 Alien addition and substitution lines .... 34 Experimental introgression . 37 Genetic engineering . 29 Electrophoresis . ^9 Breeding with Exotic Germplasm . 42 Programs utilizing exotic germplasm . 42 Genetic vulnerability . 45 III. STATEMENT OF THESIS PROBLEM . 49 IV. FIELD PERFORMANCE OF THE HYBRIDS.54 Statistical and Field Design . 54 Description of the Hybrid Lines . 54 Planting Technique for Yield Trials . 57 Field Measurements.28 Yield data.29 Metric weight . 29 Percent moisture . 29 viii Ear number.61 Days to anthesis.62 Number of tillers.62 Plant height.62 Ear measurements.63 Ear length.63 Ear width.6 3 Kernel row number.6 3 V. CYTOLOGICAL AND BIOCHEMICAL PERFORMANCE . 64 Cytological Survey . 64 Materials and methods . 64 Results.65 Electrophoretic Survey . 65 Materials and methods . 70 Running conditions . 71 Results.74 VI. RESULTS AND ANALYSIS . .•.88 Statistical Analysis . 88 Individual group traits . 88 Group I plant traits.8 8 Group II plant traits.90 Group III plant traits .94 Heterosis.97 Duncan's Multiple Range Test . 101 Combining Ability . 104 Frequency Distribution . 109 Scatter Diagrams and Correlations Analyzed by Groups.113 Scatter Diagrams and Correlations Analyzed by Hybrid Lines.110 Agronomic Analysis . 121 VII, DISCUSSION AND CONCLUSIONS . 126 Genome Variation . 126 Enhanced genome variation . 126 Heterosis Reexamined . 130 Heterosis of yield.130 Heterosis as related to hybrid pedigree ... 136 Effects of the Tripsacum chromosome associated with yield.143 Prolificacy in maize hybrids . 146 Combining Ability . 1^1 IX General combining ability . 151 Specific combining ability . 153 Alien Gene Expression.154 Genetic Improvement of Maize . 156 REFERENCES CITED . 159 APPENDIX.173 X LIST OF TABLES 1. Tribal Classifications for Corn, Teosinte, and Tripsacum. 4 2. Taxonomy of Zea as Done by Doebley and litis with Reference to that of Wilkes. 7 3. Pedigree Listing of Inbred and Hybrid Lines .... 51 4. Experiment Design Showing Mean Yields . 55 5. Analysis of Data: F Values.60 6. Cytological Examination . 66 7. Gel Reagents for Isoelectric Focusing . 72 8. Index of Electrophoretic Results . 75 9. Group I Plant and Ear Traits Expressed on a Per Plant Basis . ..89 10. Group II Plant and Ear Traits Expressed on a Per Plant Basis.92 11. Group III Plant and Ear Traits Expressed on a Per Plant Basis.95 12. Heterosis in Yield.98 13. Duncan's Range Test.102 14. General Combining Ability Values . 105 15. Parental Analysis of Variance . 106 16. Regression Analysis of Variance . 107 17. Specific Combining Ability Values . 110 18. Frequency Distribution of Yield . Ill 19. Hybrid Correlations by Group . 114 20. Hybrid Correlations for Lines 1 through 4 . 118 21. Hybrid Correlations for Lines 5 through 8 . 119 22. Agronomic Characters Ranked in Relation to Yield.122 23. Standard Deviations as Related to Heterosis .... 129 24. Total Yield as Related to Genome Constitution of the Hybrids.142 25. Phenotypic Expression of Tripsacum Chromosome . 145 XI LIST OF ILLUSTRATIONS Figure 1. Diagram of Protein Profile for the Three Imbred Tester Lines . 76 2. Diagram of Protein Profile for the Hybrids of Group I.78 3. Diagram of Protein Profile for the Hybrids of Group II.8 0 4. Diagram of Protein Profile for the Hybrids of Group III.82 5. Graphic Presentation of General Combining Ability Values . 108 6. Frequency Distribution of Total Yield Data for the Three Groups.112 7. Group I Scattergram for Total versus Prolific Yield ..131 8. Group II Scattergram for Total versus Prolific Yield . 132 9. Group III Scattergram for Total versus Prolific Yield . 133 10. Histogram Showing Total Yield Arranged by Teosinte Substitution Lines . 138 11. Histogram for Group I Hybrids Indicating the Percent of Total Yield Obtained from Prolific Yield.148 12.
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