Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2010 Soybean improvement strategies: Insect-pollinator attraction and genetic resistance to whitefly and to brown stem rot Paola T. Perez Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Agronomy and Crop Sciences Commons Recommended Citation Perez, Paola T., "Soybean improvement strategies: Insect-pollinator attraction and genetic resistance to whitefly nda to brown stem rot" (2010). Graduate Theses and Dissertations. 11402. https://lib.dr.iastate.edu/etd/11402 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Soybean improvement strategies: Insect-pollinator attraction and genetic resistance to whitefly and to brown stem rot by Paola Tatiana Perez A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Plant Breeding Program of Study Committee: Reid G. Palmer, Co-Major Professor Silvia R. Cianzio, Co-Major Professor Dianne Cook John Nason Randy Shoemaker Iowa State University Ames, Iowa 2010 ii TABLE OF CONTENTS LIST OF TABLES ................................................................................................................. iv LIST OF FIGURES ............................................................................................................... vi ACKNOWLEDGEMENTS ................................................................................................viii CHAPTER 1: GENERAL INTRODUCTION..................................................................... 1 INTRODUCTION ................................................................................................................ 1 LITERATURE REVIEW ..................................................................................................... 3 Brown stem rot (BSR) ...................................................................................................... 3 Whitefly ............................................................................................................................ 4 Soybean hybrids................................................................................................................ 5 Wild perennial Glycine species......................................................................................... 7 DISSERTATION ORGANIZATION .................................................................................. 8 REFERENCES ..................................................................................................................... 9 CHAPTER 2: GENETIC ANALYSIS OF NEW SOURCES OF SOYBEAN RESISTANCE TO BROWN STEM ROT.......................................................................... 16 ABSTRACT........................................................................................................................ 16 INTRODUCTION .............................................................................................................. 17 MATERIALS AND METHODS........................................................................................ 20 Plant material .................................................................................................................. 20 Inoculation protocol........................................................................................................ 21 Severity assays................................................................................................................ 21 DNA marker analysis...................................................................................................... 23 Data analysis ................................................................................................................... 23 RESULTS ........................................................................................................................... 24 Phenotypic analysis......................................................................................................... 24 Single marker analysis .................................................................................................... 26 DISCUSSION..................................................................................................................... 27 Acknowledgements............................................................................................................. 29 REFERENCES ................................................................................................................... 30 CHAPTER 3: QTL MAPPING OF WHITEFLY RESISTANCE IN SOYBEAN ......... 43 ABSTRACT........................................................................................................................ 43 INTRODUCTION .............................................................................................................. 44 MATERIALS AND METHODS........................................................................................ 47 Population development.................................................................................................. 47 Phenotypic evaluation..................................................................................................... 48 DNA marker analysis...................................................................................................... 49 Statistical analysis........................................................................................................... 49 RESULTS ........................................................................................................................... 51 Phenotypic analysis......................................................................................................... 51 Genotypic analysis.......................................................................................................... 52 QTL analysis................................................................................................................... 53 iii DISCUSSION..................................................................................................................... 54 Acknowledgements............................................................................................................. 57 REFERENCES ................................................................................................................... 58 CHAPTER 4: NECTAR COMPOSITION AND FLOWER CHARACTERISTICS OF WILD PERENNIAL GLYCINE SPECIES ....................................................................... 71 ABSTRACT........................................................................................................................ 72 INTRODUCTION .............................................................................................................. 73 MATERIALS AND METHODS........................................................................................ 76 Study plants..................................................................................................................... 76 Study site and methods ................................................................................................... 77 Nectar analysis and flower evaluation ............................................................................ 77 Data analysis ................................................................................................................... 78 RESULTS ........................................................................................................................... 79 Summary statistics .......................................................................................................... 79 Nectar and flower characteristics of perennial Glycine species...................................... 80 Analysis of variance........................................................................................................ 81 DISCUSSION..................................................................................................................... 82 Acknowledgements............................................................................................................. 85 REFERENCES ................................................................................................................... 85 CHAPTER 5: GENERAL CONCLUSIONS ................................................................... 106 iv LIST OF TABLES CHAPTER 2 Table 1. Visual assessment scale of brown stem rot (BSR) severity in soybean plants five weeks after inoculation.................................................................................................... 36 Table 2. Brown stem rot (BSR) resistance ratings for plate susceptibility and vigor in four F2 populations and their parental lines............................................................................ 37 Table 3. Number of F2:3 lines with higher brown stem rot (BSR) resistance than the most resistant parent or lower than the most susceptible parent by two standard deviations......... 38 Table 4. Means of genotypic classes and R2 values of molecular markers on chromosome 16 (formerly molecular linkage group J)