Edith T. Lammerts van Bueren holds an endowed chair at Wageningen University as Professor of Organic Plant Breeding and senior researcher Organic Plant Breeding at the Louis Bolk Institute in the Netherlands. James R. Myers is the Baggett-Frazier Professor of Vegetable Breeding and Genetics in the Department of Horticulture at Oregon State University.

“The editors have done an excellent job in putting together a well-organized and informative book, which covers theory, practice, issues and the latest research.”  (Experimental Agriculture, 4 October 2012)

• Contributors xiiiForeword xixWilliam F. TracyPreface xxiEdith T. Lammerts van Bueren and James R. MyersAcknowledgments xxiiiSection 1 General Topics Related to Organic Plant Breeding 1Chapter 1 Organic Crop Breeding: Integrating Organic Agricultural Approaches and Traditional and Modern Plant Breeding Methods 3Edith T. Lammerts van Bueren and James R. MyersIntroduction 3How Different Are Organic Farming Systems? 4Consequences for Cultivar Requirements 5From Cultivar Evaluation to Organic Seed Production and Plant Breeding Programs 6The History of Organic Crop Breeding in Europe and the United States 8Perspectives and Challenges for Breeding for Organic Agriculture 11Conclusion 12References 12Chapter 2 Nutrient Management in Organic Farming and Consequences for Direct and Indirect Selection Strategies 15Monika Messmer, Isabell Hildermann, Kristian Thorup-Kristensen, and Zed RengelIntroduction 15Availability of Nutrients in Organic Farming 16Roots: The Hidden Potential 17Even Greater Complexity: Plant-Microbe-Soil Interactions 21Importance of Selection Environments 27Breeding Strategies 30References 32Chapter 3 Pest and Disease Management in Organic Farming: Implications and Inspirations for Plant Breeding 39Thomas F. Döring, Marco Pautasso, Martin S. Wolfe and Maria R. FinckhIntroduction 39Plant Protection in Organic Farming 42Key Target Areas of Plant Breeding for Organic Plant Protection 46Breeding Goals for Ecological Plant Protection 49Plant Breeding Approaches Directly Targeting Pests or Diseases 50Plant Breeding Approaches with Indirect Effects on Plant Health 53Discussion and Conclusions 54References 55Chapter 4 Approaches to Breed for Improved Weed Suppression in Organically Grown Cereals 61Steve P. Hoad, Nils-Øve Bertholdsson, Daniel Neuhoff and Ulrich Köpke Background 61Crop Competitiveness against Weeds 62Crop Traits Involved in Weed Suppression 63Selection of Traits and Their Evaluation in Plant Breeding Programs 64Selection Strategies 68Understanding Crop-Weed Interactions to Assist Plant Breeding 70Concluding Remarks and Wider Perspectives 71References 72Chapter 5 Breeding for Genetically Diverse Populations: Variety Mixtures and Evolutionary Populations 77Julie C. Dawson and Isabelle GoldringerIntroduction 77Benefits of Genetic Diversity for Organic Agriculture 79On-Farm Conservation of Useful Genetic Diversity 80Breeding Strategies 81Conclusion 94References 94Chapter 6 Centralized or Decentralized Breeding: The Potentials of Participatory Approaches for Low-Input and Organic Agriculture 99Dominique Desclaux, Salvatore Ceccarelli, John Navazio, Micaela Coley,Gilles Trouche, Silvio Aguirre, Eva Weltzien, and Jacques LançonIntroduction 99Centralized and Decentralized Breeding: Definitions 100What Can Be Decentralized in Breeding and Why? 100Participatory Approaches 102PPB: A Single Term Yielding Different Approaches 102Some Examples of PPB for Organic and Low Input Agriculture in Southern Countries 106Some Examples of PPB for Organic and Low Input Agriculture in Northern Countries 113General Conclusions and Limits of PPB Approaches in Organic Farming 119References 120Chapter 7 Values and Principles in Organic Farming and Consequences for Breeding Approaches and Techniques 125Klaus P. Wilbois, Brian Baker, Maaike Raaijmakers and Edith T. Lammerts van BuerenIntroduction 125Arguments against Genetic Engineering 126Organic Basic Principles 127Toward Organic Breeding 130From Values to Criteria: Evaluation of Breeding Techniques 131How to Deal with Varieties Bred with Non-compliant Techniques? 132Toward Appropriate Standards to Promote Organic Plant Breeding 135Discussion and Challenges for Organic Plant Breeding 136References 136Chapter 8 Plant Breeding, Variety Release, and Seed Commercialization: Laws and Policies Applied to the Organic Sector 139Véronique Chable, Niels Louwaars, Kristina Hubbard, Brian Baker, and Riccardo BocciIntroduction 139The Developments of Plant Breeding and the Emergence of Seed Laws 139Variety Registration 142Seed Quality Control and Certification 144Special Needs for Organic Agriculture 146A Recent Development in Europe: Conservation Varieties 148Intellectual Property Rights and Plant Breeding 151Discussion 154Conclusions 156Notes 156References 157Section 2 Organic Plant Breeding in Specific Crops 161Chapter 9 Wheat: Breeding for Organic Farming Systems 163Matt Arterburn, Kevin Murphy, and Steve S. JonesIntroduction 163Methods 163Traits for Selection in Organic Breeding Programs 168A Case Study for EPB: Lexi’s Project 170A Case Study for Breeding within a Supply Chain Approach: Peter Kunz and Sativa 171Conclusion 171References 172Chapter 10 Maize: Breeding and Field Testing for Organic Farmers 175Walter A. Goldstein, Walter Schmidt, Henriette Burger, Monika Messmer, Linda M. Pollak, Margaret E. Smith, Major M. Goodman, Frank J. Kutka and Richard C. PrattIntroduction 175What Kind of Maize do Organic Farmers Want? 175Are There Viable Alternatives to Single Cross Hybrids? 176Testing and Using Alternative Hybrids 178Are There Benefits for Breeding under Organic Conditions? 178For Which Traits Is It Necessary to Test under Organic Conditions? 179Choice of Parents for Breeding Programs 181Breeding Programs 182Future Directions 186Notes 186References 188Chapter 11 Rice: Crop Breeding Using Farmer-Led Participatory Plant Breeding 191Charito P. MedinaIntroduction 191MASIPAG and Participatory Rice Breeding 192Beyond PPB: Farmer-Led Rice Breeding 193The Breeding Process 194Outcomes of the MASIPAG Program 198Outlook 200References 201Chapter 12 Soybean: Breeding for Organic Farming Systems 203Johann Vollmann and Michelle MenkenIntroduction 203Agronomic Characters 204Seed Quality Features 208Considerations on Breeding Methods 211References 212Chapter 13 Faba Bean: Breeding for Organic Farming Systems 215Wolfgang Link and Lamiae GhaoutiPurposes of Breeding and Growing Faba Bean 215Genetic and Botanical Basics of Breeding Faba Bean 216Methodological Considerations 218Traits to Be Improved in Faba Bean Breeding 221Open Questions, Need for Action 223References 224Chapter 14 Potato: Perspectives to Breed for an Organic Crop Ideotype 227Marjolein Tiemens-Hulscher, Edith T. Lammerts van Bueren and Ronald C.B. HuttenIntroduction 227Required Cultivar Characteristics 228Introgression Breeding and Applied Techniques 232Participatory Approach: An Example from the Netherlands 233Outlook 234References 234Chapter 15 Tomato: Breeding for Improved Disease Resistance in Fresh Market and Home Garden Varieties 239Bernd Horneburg and James R. MyersIntroduction 239Botanical and Genetic Characteristics of Tomato 240Rationale for Breeding Tomatoes within Organic Systems 240Breeding Needs with Focus on Organic Production 243Case Studies: Breeding for Late Blight Resistance in Europe and North America 245Outlook 247References 248Chapter 16 Brassicas: Breeding Cole Crops for Organic Agriculture 251James R. Myers, Laurie McKenzie, and Roeland E. VoorripsIntroduction 251Rationale for Breeding within Organic Systems 251Plant Biology 252Traits Needed for Adaptation to Organic Production 253Consideration of Breeding Methods 257A Farmer Participatory Broccoli Breeding Program 258Outlook 260References 261Chapter 17 Onions: Breeding Onions for Low-Input and Organic Agriculture 263Olga E. Scholten and Thomas W. KuyperIntroduction 263Robust Onion Cultivars 264Breeding for Improved Nutrient Acquisition 265Mycorrhizal Symbiosis and Product Quality 269Conclusion 270References 271Index 273

Edith T. Lammerts van Bueren holds an endowed chair at Wageningen University as Professor of Organic Plant Breeding and senior researcher Organic Plant Breeding at the Louis Bolk Institute in the Netherlands. James R. Myers is the Baggett-Frazier Professor of Vegetable Breeding and Genetics in the Department of Horticulture at Oregon State University.

“The editors have done an excellent job in putting together a well-organized and informative book, which covers theory, practice, issues and the latest research.”  (Experimental Agriculture, 4 October 2012)

• Contributors xiiiForeword xixWilliam F. TracyPreface xxiEdith T. Lammerts van Bueren and James R. MyersAcknowledgments xxiiiSection 1 General Topics Related to Organic Plant Breeding 1Chapter 1 Organic Crop Breeding: Integrating Organic Agricultural Approaches and Traditional and Modern Plant Breeding Methods 3Edith T. Lammerts van Bueren and James R. MyersIntroduction 3How Different Are Organic Farming Systems? 4Consequences for Cultivar Requirements 5From Cultivar Evaluation to Organic Seed Production and Plant Breeding Programs 6The History of Organic Crop Breeding in Europe and the United States 8Perspectives and Challenges for Breeding for Organic Agriculture 11Conclusion 12References 12Chapter 2 Nutrient Management in Organic Farming and Consequences for Direct and Indirect Selection Strategies 15Monika Messmer, Isabell Hildermann, Kristian Thorup-Kristensen, and Zed RengelIntroduction 15Availability of Nutrients in Organic Farming 16Roots: The Hidden Potential 17Even Greater Complexity: Plant-Microbe-Soil Interactions 21Importance of Selection Environments 27Breeding Strategies 30References 32Chapter 3 Pest and Disease Management in Organic Farming: Implications and Inspirations for Plant Breeding 39Thomas F. Döring, Marco Pautasso, Martin S. Wolfe and Maria R. FinckhIntroduction 39Plant Protection in Organic Farming 42Key Target Areas of Plant Breeding for Organic Plant Protection 46Breeding Goals for Ecological Plant Protection 49Plant Breeding Approaches Directly Targeting Pests or Diseases 50Plant Breeding Approaches with Indirect Effects on Plant Health 53Discussion and Conclusions 54References 55Chapter 4 Approaches to Breed for Improved Weed Suppression in Organically Grown Cereals 61Steve P. Hoad, Nils-Øve Bertholdsson, Daniel Neuhoff and Ulrich Köpke Background 61Crop Competitiveness against Weeds 62Crop Traits Involved in Weed Suppression 63Selection of Traits and Their Evaluation in Plant Breeding Programs 64Selection Strategies 68Understanding Crop-Weed Interactions to Assist Plant Breeding 70Concluding Remarks and Wider Perspectives 71References 72Chapter 5 Breeding for Genetically Diverse Populations: Variety Mixtures and Evolutionary Populations 77Julie C. Dawson and Isabelle GoldringerIntroduction 77Benefits of Genetic Diversity for Organic Agriculture 79On-Farm Conservation of Useful Genetic Diversity 80Breeding Strategies 81Conclusion 94References 94Chapter 6 Centralized or Decentralized Breeding: The Potentials of Participatory Approaches for Low-Input and Organic Agriculture 99Dominique Desclaux, Salvatore Ceccarelli, John Navazio, Micaela Coley,Gilles Trouche, Silvio Aguirre, Eva Weltzien, and Jacques LançonIntroduction 99Centralized and Decentralized Breeding: Definitions 100What Can Be Decentralized in Breeding and Why? 100Participatory Approaches 102PPB: A Single Term Yielding Different Approaches 102Some Examples of PPB for Organic and Low Input Agriculture in Southern Countries 106Some Examples of PPB for Organic and Low Input Agriculture in Northern Countries 113General Conclusions and Limits of PPB Approaches in Organic Farming 119References 120Chapter 7 Values and Principles in Organic Farming and Consequences for Breeding Approaches and Techniques 125Klaus P. Wilbois, Brian Baker, Maaike Raaijmakers and Edith T. Lammerts van BuerenIntroduction 125Arguments against Genetic Engineering 126Organic Basic Principles 127Toward Organic Breeding 130From Values to Criteria: Evaluation of Breeding Techniques 131How to Deal with Varieties Bred with Non-compliant Techniques? 132Toward Appropriate Standards to Promote Organic Plant Breeding 135Discussion and Challenges for Organic Plant Breeding 136References 136Chapter 8 Plant Breeding, Variety Release, and Seed Commercialization: Laws and Policies Applied to the Organic Sector 139Véronique Chable, Niels Louwaars, Kristina Hubbard, Brian Baker, and Riccardo BocciIntroduction 139The Developments of Plant Breeding and the Emergence of Seed Laws 139Variety Registration 142Seed Quality Control and Certification 144Special Needs for Organic Agriculture 146A Recent Development in Europe: Conservation Varieties 148Intellectual Property Rights and Plant Breeding 151Discussion 154Conclusions 156Notes 156References 157Section 2 Organic Plant Breeding in Specific Crops 161Chapter 9 Wheat: Breeding for Organic Farming Systems 163Matt Arterburn, Kevin Murphy, and Steve S. JonesIntroduction 163Methods 163Traits for Selection in Organic Breeding Programs 168A Case Study for EPB: Lexi’s Project 170A Case Study for Breeding within a Supply Chain Approach: Peter Kunz and Sativa 171Conclusion 171References 172Chapter 10 Maize: Breeding and Field Testing for Organic Farmers 175Walter A. Goldstein, Walter Schmidt, Henriette Burger, Monika Messmer, Linda M. Pollak, Margaret E. Smith, Major M. Goodman, Frank J. Kutka and Richard C. PrattIntroduction 175What Kind of Maize do Organic Farmers Want? 175Are There Viable Alternatives to Single Cross Hybrids? 176Testing and Using Alternative Hybrids 178Are There Benefits for Breeding under Organic Conditions? 178For Which Traits Is It Necessary to Test under Organic Conditions? 179Choice of Parents for Breeding Programs 181Breeding Programs 182Future Directions 186Notes 186References 188Chapter 11 Rice: Crop Breeding Using Farmer-Led Participatory Plant Breeding 191Charito P. MedinaIntroduction 191MASIPAG and Participatory Rice Breeding 192Beyond PPB: Farmer-Led Rice Breeding 193The Breeding Process 194Outcomes of the MASIPAG Program 198Outlook 200References 201Chapter 12 Soybean: Breeding for Organic Farming Systems 203Johann Vollmann and Michelle MenkenIntroduction 203Agronomic Characters 204Seed Quality Features 208Considerations on Breeding Methods 211References 212Chapter 13 Faba Bean: Breeding for Organic Farming Systems 215Wolfgang Link and Lamiae GhaoutiPurposes of Breeding and Growing Faba Bean 215Genetic and Botanical Basics of Breeding Faba Bean 216Methodological Considerations 218Traits to Be Improved in Faba Bean Breeding 221Open Questions, Need for Action 223References 224Chapter 14 Potato: Perspectives to Breed for an Organic Crop Ideotype 227Marjolein Tiemens-Hulscher, Edith T. Lammerts van Bueren and Ronald C.B. HuttenIntroduction 227Required Cultivar Characteristics 228Introgression Breeding and Applied Techniques 232Participatory Approach: An Example from the Netherlands 233Outlook 234References 234Chapter 15 Tomato: Breeding for Improved Disease Resistance in Fresh Market and Home Garden Varieties 239Bernd Horneburg and James R. MyersIntroduction 239Botanical and Genetic Characteristics of Tomato 240Rationale for Breeding Tomatoes within Organic Systems 240Breeding Needs with Focus on Organic Production 243Case Studies: Breeding for Late Blight Resistance in Europe and North America 245Outlook 247References 248Chapter 16 Brassicas: Breeding Cole Crops for Organic Agriculture 251James R. Myers, Laurie McKenzie, and Roeland E. VoorripsIntroduction 251Rationale for Breeding within Organic Systems 251Plant Biology 252Traits Needed for Adaptation to Organic Production 253Consideration of Breeding Methods 257A Farmer Participatory Broccoli Breeding Program 258Outlook 260References 261Chapter 17 Onions: Breeding Onions for Low-Input and Organic Agriculture 263Olga E. Scholten and Thomas W. KuyperIntroduction 263Robust Onion Cultivars 264Breeding for Improved Nutrient Acquisition 265Mycorrhizal Symbiosis and Product Quality 269Conclusion 270References 271Index 273

Edith T. Lammerts van Bueren holds an endowed chair at Wageningen University as Professor of Organic Plant Breeding and senior researcher Organic Plant Breeding at the Louis Bolk Institute in the Netherlands. James R. Myers is the Baggett-Frazier Professor of Vegetable Breeding and Genetics in the Department of Horticulture at Oregon State University.

“The editors have done an excellent job in putting together a well-organized and informative book, which covers theory, practice, issues and the latest research.”  (Experimental Agriculture, 4 October 2012)

• Contributors xiiiForeword xixWilliam F. TracyPreface xxiEdith T. Lammerts van Bueren and James R. MyersAcknowledgments xxiiiSection 1 General Topics Related to Organic Plant Breeding 1Chapter 1 Organic Crop Breeding: Integrating Organic Agricultural Approaches and Traditional and Modern Plant Breeding Methods 3Edith T. Lammerts van Bueren and James R. MyersIntroduction 3How Different Are Organic Farming Systems? 4Consequences for Cultivar Requirements 5From Cultivar Evaluation to Organic Seed Production and Plant Breeding Programs 6The History of Organic Crop Breeding in Europe and the United States 8Perspectives and Challenges for Breeding for Organic Agriculture 11Conclusion 12References 12Chapter 2 Nutrient Management in Organic Farming and Consequences for Direct and Indirect Selection Strategies 15Monika Messmer, Isabell Hildermann, Kristian Thorup-Kristensen, and Zed RengelIntroduction 15Availability of Nutrients in Organic Farming 16Roots: The Hidden Potential 17Even Greater Complexity: Plant-Microbe-Soil Interactions 21Importance of Selection Environments 27Breeding Strategies 30References 32Chapter 3 Pest and Disease Management in Organic Farming: Implications and Inspirations for Plant Breeding 39Thomas F. Döring, Marco Pautasso, Martin S. Wolfe and Maria R. FinckhIntroduction 39Plant Protection in Organic Farming 42Key Target Areas of Plant Breeding for Organic Plant Protection 46Breeding Goals for Ecological Plant Protection 49Plant Breeding Approaches Directly Targeting Pests or Diseases 50Plant Breeding Approaches with Indirect Effects on Plant Health 53Discussion and Conclusions 54References 55Chapter 4 Approaches to Breed for Improved Weed Suppression in Organically Grown Cereals 61Steve P. Hoad, Nils-Øve Bertholdsson, Daniel Neuhoff and Ulrich Köpke Background 61Crop Competitiveness against Weeds 62Crop Traits Involved in Weed Suppression 63Selection of Traits and Their Evaluation in Plant Breeding Programs 64Selection Strategies 68Understanding Crop-Weed Interactions to Assist Plant Breeding 70Concluding Remarks and Wider Perspectives 71References 72Chapter 5 Breeding for Genetically Diverse Populations: Variety Mixtures and Evolutionary Populations 77Julie C. Dawson and Isabelle GoldringerIntroduction 77Benefits of Genetic Diversity for Organic Agriculture 79On-Farm Conservation of Useful Genetic Diversity 80Breeding Strategies 81Conclusion 94References 94Chapter 6 Centralized or Decentralized Breeding: The Potentials of Participatory Approaches for Low-Input and Organic Agriculture 99Dominique Desclaux, Salvatore Ceccarelli, John Navazio, Micaela Coley,Gilles Trouche, Silvio Aguirre, Eva Weltzien, and Jacques LançonIntroduction 99Centralized and Decentralized Breeding: Definitions 100What Can Be Decentralized in Breeding and Why? 100Participatory Approaches 102PPB: A Single Term Yielding Different Approaches 102Some Examples of PPB for Organic and Low Input Agriculture in Southern Countries 106Some Examples of PPB for Organic and Low Input Agriculture in Northern Countries 113General Conclusions and Limits of PPB Approaches in Organic Farming 119References 120Chapter 7 Values and Principles in Organic Farming and Consequences for Breeding Approaches and Techniques 125Klaus P. Wilbois, Brian Baker, Maaike Raaijmakers and Edith T. Lammerts van BuerenIntroduction 125Arguments against Genetic Engineering 126Organic Basic Principles 127Toward Organic Breeding 130From Values to Criteria: Evaluation of Breeding Techniques 131How to Deal with Varieties Bred with Non-compliant Techniques? 132Toward Appropriate Standards to Promote Organic Plant Breeding 135Discussion and Challenges for Organic Plant Breeding 136References 136Chapter 8 Plant Breeding, Variety Release, and Seed Commercialization: Laws and Policies Applied to the Organic Sector 139Véronique Chable, Niels Louwaars, Kristina Hubbard, Brian Baker, and Riccardo BocciIntroduction 139The Developments of Plant Breeding and the Emergence of Seed Laws 139Variety Registration 142Seed Quality Control and Certification 144Special Needs for Organic Agriculture 146A Recent Development in Europe: Conservation Varieties 148Intellectual Property Rights and Plant Breeding 151Discussion 154Conclusions 156Notes 156References 157Section 2 Organic Plant Breeding in Specific Crops 161Chapter 9 Wheat: Breeding for Organic Farming Systems 163Matt Arterburn, Kevin Murphy, and Steve S. JonesIntroduction 163Methods 163Traits for Selection in Organic Breeding Programs 168A Case Study for EPB: Lexi’s Project 170A Case Study for Breeding within a Supply Chain Approach: Peter Kunz and Sativa 171Conclusion 171References 172Chapter 10 Maize: Breeding and Field Testing for Organic Farmers 175Walter A. Goldstein, Walter Schmidt, Henriette Burger, Monika Messmer, Linda M. Pollak, Margaret E. Smith, Major M. Goodman, Frank J. Kutka and Richard C. PrattIntroduction 175What Kind of Maize do Organic Farmers Want? 175Are There Viable Alternatives to Single Cross Hybrids? 176Testing and Using Alternative Hybrids 178Are There Benefits for Breeding under Organic Conditions? 178For Which Traits Is It Necessary to Test under Organic Conditions? 179Choice of Parents for Breeding Programs 181Breeding Programs 182Future Directions 186Notes 186References 188Chapter 11 Rice: Crop Breeding Using Farmer-Led Participatory Plant Breeding 191Charito P. MedinaIntroduction 191MASIPAG and Participatory Rice Breeding 192Beyond PPB: Farmer-Led Rice Breeding 193The Breeding Process 194Outcomes of the MASIPAG Program 198Outlook 200References 201Chapter 12 Soybean: Breeding for Organic Farming Systems 203Johann Vollmann and Michelle MenkenIntroduction 203Agronomic Characters 204Seed Quality Features 208Considerations on Breeding Methods 211References 212Chapter 13 Faba Bean: Breeding for Organic Farming Systems 215Wolfgang Link and Lamiae GhaoutiPurposes of Breeding and Growing Faba Bean 215Genetic and Botanical Basics of Breeding Faba Bean 216Methodological Considerations 218Traits to Be Improved in Faba Bean Breeding 221Open Questions, Need for Action 223References 224Chapter 14 Potato: Perspectives to Breed for an Organic Crop Ideotype 227Marjolein Tiemens-Hulscher, Edith T. Lammerts van Bueren and Ronald C.B. HuttenIntroduction 227Required Cultivar Characteristics 228Introgression Breeding and Applied Techniques 232Participatory Approach: An Example from the Netherlands 233Outlook 234References 234Chapter 15 Tomato: Breeding for Improved Disease Resistance in Fresh Market and Home Garden Varieties 239Bernd Horneburg and James R. MyersIntroduction 239Botanical and Genetic Characteristics of Tomato 240Rationale for Breeding Tomatoes within Organic Systems 240Breeding Needs with Focus on Organic Production 243Case Studies: Breeding for Late Blight Resistance in Europe and North America 245Outlook 247References 248Chapter 16 Brassicas: Breeding Cole Crops for Organic Agriculture 251James R. Myers, Laurie McKenzie, and Roeland E. VoorripsIntroduction 251Rationale for Breeding within Organic Systems 251Plant Biology 252Traits Needed for Adaptation to Organic Production 253Consideration of Breeding Methods 257A Farmer Participatory Broccoli Breeding Program 258Outlook 260References 261Chapter 17 Onions: Breeding Onions for Low-Input and Organic Agriculture 263Olga E. Scholten and Thomas W. KuyperIntroduction 263Robust Onion Cultivars 264Breeding for Improved Nutrient Acquisition 265Mycorrhizal Symbiosis and Product Quality 269Conclusion 270References 271Index 273