Seed Science and Technology: Biology, Production, Quality

Preface
Contents
Editors and Contributors
Seed Quality: Variety Development to Planting-An Overview
	1 Introduction
	2 Seed Development
	3 System of Variety Development, Release, and Notification
	4 Seed Production
	5 Variety Maintenance/Maintenance Breeding
	6 Seed Quality
		6.1 Physical Quality
		6.2 Genetic Purity
		6.3 Physiological Quality
		6.4 Seed Health
	7 Factors Influencing Seed Quality
	8 Seed Quality Assurance
	9 Seed Certification and Quality Testing
	10 Role of International Organizations
	11 Seed Quality Maintenance
	12 Seed Quality Upgradation
	13 Genetic Improvement for Seed Quality
	14 Seed Quality Enhancement
	15 Scope of Molecular Technologies
	References
Seed Development and Maturation
	1 Introduction
	2 Double Fertilization
	3 Embryogenesis
		3.1 Embryogenesis in Monocot
		3.2 Embryogenesis in Dicot
	4 Acquisition of Desiccation Tolerance During Seed Maturation
	5 Seed Development and Maturation in Relevance to Seed Quality
		5.1 Hormonal Regulation of Seed Development and Maturation
	6 Physiological Maturity, Mass Maturity and Harvest Maturity
		6.1 Seed Maturity Indices in Relation to Harvest Maturity
		6.2 Trackable Parameters During Seed Development and Maturation
			6.2.1 Seed Moisture Content
			6.2.2 Seed Size
			6.2.3 Seed Dry Weight
			6.2.4 Germination
			6.2.5 Vigour
		6.3 Chlorophyll Fluorescence (CF) Sorting vis-à-vis Seed Maturation
		6.4 External Factors Affecting Seed Development and Maturation
			6.4.1 Soil Fertility
			6.4.2 Water
			6.4.3 Temperature
			6.4.4 Light
			6.4.5 Seed Position on the Plant
	7 Conclusion
	References
Seed Dormancy and Regulation of Germination
	1 Introduction
	2 Seed Dormancy
		2.1 Definition
		2.2 Classification of Seed Dormancy
			2.2.1 Morphological Dormancy
			2.2.2 Physiological Dormancy
			2.2.3 Physical Dormancy
			2.2.4 Combinational Dormancy
		2.3 Types of Seed Dormancy in Legumes and Cereals
		2.4 Induction of Dormancy
			2.4.1 Primary Dormancy
			2.4.2 Secondary Dormancy
		2.5 Phytochrome and Seed Dormancy vs. Germination
		2.6 Methods to Release Dormancy
			2.6.1 Scarification
			2.6.2 Stratification
			2.6.3 Leaching of Metabolites (Inhibitors)
			2.6.4 Treating Seed with Chemical Activators and Growth Hormones
	3 Seed Germination
		3.1 Morphology of Seed Germination
		3.2 Metabolic Processes During Seed Germination
			3.2.1 Hydrolytic Enzymes and Seed Germination
			3.2.2 Hydrolysis of Starch
			3.2.3 Hydrolysis of Proteins
			3.2.4 Hydrolysis of Lipids
			3.2.5 Hydrolysis of Phytic Acid
		3.3 ROS Function
		3.4 Nitrogenous Compounds and Seed Germination
		3.5 Mobilisation of Reserve Food Material
		3.6 Hormone Metabolism and Signalling
		3.7 Ethylene and Other Growth Regulators
		3.8 Environmental Factors Influencing Seed Germination
	4 Conclusions and Future Thrust Areas
	References
Seed Vigour and Invigoration
	1 Introduction
		1.1 Definitions of Seed Vigour
	2 Factors Affecting Seed Vigour
		2.1 Acquisition of Seed Vigour and Seed Maturity
		2.2 Environment
		2.3 Seed Size
		2.4 Seed Reserves
		2.5 Positional Effect
		2.6 Seed Coat and Imbibition Damage
		2.7 Seed Ageing and Storage
		2.8 Seed Processing
		2.9 Physical Sanitation Treatment
		2.10 Genetic Variation
	3 Seed Vigour Assessment
		3.1 Seed Vigour Tests
			3.1.1 Seed Size/Density
			3.1.2 Performance-Based Tests
			3.1.3 Stress Tests
			3.1.4 Physiological and Biochemical Tests
		3.2 Some Novel Methods of Vigour Assessment
	4 Seed Invigoration
		4.1 Effect of Seed Priming
			4.1.1 Biophysical and Structural Changes
			4.1.2 Cellular and Metabolic Changes
			4.1.3 Physiological and Biochemical Changes
			4.1.4 Stress Resistance
		4.2 Storage of Primed Seeds
	5 Conclusion
	References
Seed Longevity and Deterioration
	1 Introduction
	2 Seed Factors
		2.1 Role of Chemical Protectants in Various Tissues
		2.2 Role of Hormones
	3 Storage Factors
		3.1 Moisture Content, Water Activity or Equilibrium Relative Humidity
			3.1.1 Glassy or Liquid Cytoplasm
		3.2 Temperature
		3.3 Oxygen
		3.4 Pests and Pathogens
	4 Modelling Seed Ageing
	5 Estimating Seed Longevity
	6 Types and Causes of Seed Deterioration
	7 Repair Mechanisms
	8 Storability of Recalcitrant Seeds
	References
Principles of Quality Seed Production
	1 Introduction
	2 Variety Release and Seed Certification
	3 Generation Scheme of Seed Multiplication
	4 Genetic Deterioration in Crop Varieties
		4.1 Genotypic Constitution and Pollination Behaviour
		4.2 Developmental Variation
		4.3 Mechanical Mixtures
		4.4 Natural Out-Crossing
		4.5 Influence of Pests and Diseases
		4.6 Genetic Drift
		4.7 Minor Genetic Variations and Pre-mature Release of Varieties
	5 Principles of Quality Seed Production
		5.1 Genetic Principles of Seed Production
			5.1.1 Maintenance Breeding
			5.1.2 Confirmation of the Seed Source
			5.1.3 Previous Cropping History
			5.1.4 Isolation Requirement
				Isolation in Time
				Isolation by Distance
				Isolation by Barrier
			5.1.5 Compact Area Approach
			5.1.6 Discarding the Peripheral Strip
		5.2 Agronomic Principles of Seed Production
			5.2.1 Selection of the Agro-Climatic Region
			5.2.2 Field Preparation
			5.2.3 Selection of a Variety
			5.2.4 Seeding and Stand Establishment
			5.2.5 Roguing of the Seed Crop
			5.2.6 Weed Control
			5.2.7 Disease and Insect Control
			5.2.8 Soil Fertility and Plant Nutrition
		5.3 Seed Technology Principles
			5.3.1 Selection of Field
			5.3.2 Supplementary Pollination
			5.3.3 Harvesting
			5.3.4 Drying and Storage of Raw Seed
			5.3.5 Seed Conditioning and Upgradation
			5.3.6 Seed Treatment
			5.3.7 Seed Packaging and Storage
			5.3.8 Seed Certification
			5.3.9 Seed Certification Procedures
				Application
				Field Inspection
				Seed Sampling, Testing and Tagging
			5.3.10 Marketing
	6 Conclusion
	References
Vegetable Seed Production
	1 Introduction
	2 Seed Quality Parameters
		2.1 Genetic Purity
			2.1.1 Breeder Seed
			2.1.2 Foundation Seed
			2.1.3 Certified Seed
			2.1.4 Labelled Seed
	3 Seed Certification
	4 Seed Production Technology
		4.1 Environmental Requirements
		4.2 Land Requirements and Planting
		4.3 Pollination Requirements
		4.4 Isolation Requirements
			4.4.1 Temporal Isolation
			4.4.2 Spatial Isolation
			4.4.3 Isolation by Physical Barrier
	5 Roguing
		5.1 Different Stages of Rouging
	6 Harvesting, Threshing and Seed Extraction
		6.1 Fermentation
		6.2 Acid Treatment
		6.3 Alkali Treatment
	7 Seed Drying
	8 Seed Processing
	9 Seed Quality Control
	10 Genetic Purity
	11 Opportunities in Vegetable Seed Production
	References
Principles of Variety Maintenance for Quality Seed Production
	1 Introduction
		1.1 Quality Control: An Essential Prerequisite of Varietal Maintenance and Seed Multiplication
	2 Maintenance Breeding
		2.1 Objectives of the Maintenance Breeding
		2.2 Methodology
			2.2.1 Self-Pollinated Crops
				Rice
					Pusa Basmati 1121
					Pusa 44
				Wheat
					Nucleus Seed Stage I (NSS1)
					Nucleus Seed Stage II (NSS2)
			2.2.2 Often Cross-Pollinated Crops, e.g., Pigeon Pea
				Nucleus Seed Production of Varieties and/or Restorer Lines of Hybrids
				Nucleus Seed Production of A Line of Pigeon Pea Hybrids
			2.2.3 Cross-Pollinated Crops, e.g. Sunflower
				Nucleus Seed Production of Open-Pollinated Varieties
				Nucleus Seed Production of R Line
	3 Measures to Evaluate Varietal Purity to Increase Homogeneity and Stability
	4 Conclusion
	References
Hybrid Seed Production Technology
	1 Introduction
	2 Genetic Principles in Hybrid Seed Production
		2.1 Male Sterility
			2.1.1 Genetic Male Sterility (GMS)
			2.1.2 Cytoplasmic Male Sterility (CMS)
			2.1.3 Cytoplasmic-Genetic Male Sterility (CGMS)
		2.2 Self-Incompatibility
		2.3 Emasculation and Pollination
		2.4 Use of Gynoecious Sex Form
		2.5 Use of Chemicals and Growth Regulators
			2.5.1 Sex Modification through Hormones and Chemicals
		2.6 Manipulation of Environment for Sex Modification in Hybrid Seed Production
			2.6.1 Rice
			2.6.2 Castor
	3 Agronomic Principles of Hybrid Seed Production
		3.1 Environmental Requirements
		3.2 Land Requirement
		3.3 Isolation Distance
	4 Stigma Receptivity
	5 Pollen Viability
	6 Pollination Control
	7 Synchronization of Flowering
		7.1 Rice
		7.2 Sorghum
		7.3 Pearl Millet
		7.4 Sunflower
		7.5 Cauliflower
	8 Planting Ratio
	9 Supplementary Pollination
	10 Roguing
	11 Harvesting, Threshing and Seed Extraction
	12 Seed Drying
	13 Hybrid Seed Production in Maize (Zea mays L.)
		13.1 Selection of Area
		13.2 Field Selection
		13.3 Isolation
			13.3.1 Spatial Isolation
			13.3.2 Temporal Isolation
			13.3.3 Border Rows
		13.4 Use of Border Rows
		13.5 Planting Pattern
		13.6 Pollen Control
			13.6.1 Precautions During Detasseling
		13.7 Flowering Manipulation
		13.8 Rogueing
	14 Hybrid Seed Production in Castor (Ricinus communis L.)
		14.1 Isolation
		14.2 Season and Planting Condition
		14.3 Breeder/Foundation Seed Production of Female Parents
			14.3.1 Conventional Method
			14.3.2 Modified Method
			14.3.3 Other Precautions
		14.4 Certified Hybrid Seed Production
	15 Hybrid Seed Production in Cotton
		15.1 Emasculation of the Female Parent
			15.1.1 Doak Method or Thumb Nail Method
			15.1.2 Pinching off of the Top of Corolla
			15.1.3 Straw Tube/Copper Straw Method
			15.1.4 Removal of Petals and Dusting off Anthers
		15.2 Pollination
	16 Hybrid Wheat Seed Production
	17 Hybrid Seed Production in Tomato under Polyhouse Conditions
		17.1 Growing Seedling
		17.2 Transplanting
		17.3 Intercultural Operations
		17.4 Emasculation
		17.5 Pollen Collection
		17.6 Pollination
		17.7 Harvesting
		17.8 Seed Extraction
	18 Hybrid Seed Production in Bitter Gourd under Insect-Proof Net House
		18.1 Flowering Behaviour
		18.2 Pollination
		18.3 Seed Extraction
	19 Cauliflower
	References
Seed Processing for Quality Upgradation
	1 Introduction
	2 Conditioning
		2.1 Moisture Conditioning
	3 Seed Drying
		3.1 Batch Drying System
			3.1.1 Bin Dryer
			3.1.2 Tray Dryer
			3.1.3 Tunnel Dryer
		3.2 Continuous Drying System
			3.2.1 Rotary Dryer
			3.2.2 Column Dryer
			3.2.3 Belt Dryer
			3.2.4 Fluidized Bed Dryer
		3.3 Heated Air Dryers
			3.3.1 Direct Fired Type
			3.3.2 Indirect Fired Type
	4 Tempering
	5 Removal of Appendages
		5.1 Hammer Mill
		5.2 Debearder
		5.3 Pebble Mill
		5.4 Scalper
		5.5 Huller and Scarifier
	6 Removal of Dockage
	7 Cleaning and Grading
		7.1 Air Screen Cleaner Cum Grader
		7.2 Indented Cylinder Separator
		7.3 Specific Gravity Separator
		7.4 Pneumatic Separator
		7.5 Electric Separator
		7.6 Spiral Separator
		7.7 Inclined Draper
		7.8 Magnetic Separator
		7.9 Horizontal Disk Separator
		7.10 Colour Sorter
		7.11 X-Ray Sorter
	8 Seed Treatment
		8.1 Dry Seed Treater
		8.2 Slurry Seed Treater
		8.3 Mist-O-Matic Seed Treater
		8.4 Thermoseed Treatment
	9 Seed Coating and Pelleting
	10 Seed Packaging
	References
Seed Storage and Packaging
	1 Introduction
	2 Purpose of Seed Storage
	3 Factors Affecting Seed Storability
		3.1 Seed Factors
		3.2 Storage Factors
	4 Management of Storage Factors
		4.1 Management of Moisture
			4.1.1 Seed Drying
			4.1.2 Natural Drying
			4.1.3 Commercial Drying
			4.1.4 Management of Temperature
			4.1.5 Gaseous Composition of the Storage Environment
		4.2 Seed Packaging
		4.3 Storage Structures
		4.4 On-Farm Safe Seed Storage
	5 Management of Diseases and Insect Pests During Storage
		5.1 Seed Health Management During Storage
		5.2 Microbial Damage
		5.3 Storage Insect Pests
			5.3.1 Monitoring and Detection of Insect Infestation
			5.3.2 Monitoring of Insect Infestation in Seed Stores and Bulk Godowns
				Detection of External Infestation in Seed Lots
	6 Good Storage Practices as a Preventive Measure
		6.1 Pre-Storage Preventive Measures
			6.1.1 Preparation of Seed Stocks
			6.1.2 Preparation of Seed Store/Shed
			6.1.3 Thermal Treatment
			6.1.4 Solar Heat (Solarization)
			6.1.5 Cold Storage
			6.1.6 Controlled Conditioned Seed Storage
			6.1.7 Fumigants
			6.1.8 Hydrogen Phosphide or Phosphine (PH3)
	7 Pre- and Post-Harvest Strategies for Disease Management
	8 Long-Term Seed Preservation
	References
Role of Seed Certification in Quality Assurance
	1 Seed Quality Assurance
		1.1 Seed Certification
			1.1.1 Seed Certification System Operating in the USA, EU, and the UK
				Variety Release: Pre-condition for Certification
				Seed Certification Phases
			1.1.2 Accreditation for Seed Certification System
		1.2 Truth-in-Labelling/Truthfully Labelling System
		1.3 Seed Quality Assurance System in India and Other SAARC Countries
		1.4 Quality Declared Seed (QDS) System
			Quality Declared Seeds Production in Tanzania (Pearl Millet, Sorghum, and Groundnut 2016)
			QDS Filling the Gap Between Formal and Informal Seed Systems: A Case of Common Beans in Uganda 2013
	2 International Certification Systems for Seed Movement
		2.1 Association of Official Seed Certifying Agencies (AOSCA)
		2.2 Organization for Economic Cooperation and Development (OECD) Seed Schemes
			2.2.1 OECD Labels
		2.3 International Seed Testing Association (ISTA)
		2.4 International Plant Protection Convention (IPPC)
	References
Testing Seed for Quality
	1 Introduction
	2 Seed Sampling
		2.1 Seed Sampling Procedure
	3 Seed Testing
		3.1 Physical Purity
			3.1.1 Components of Physical Purity Analysis
			3.1.2 Objectives of Physical Purity Analysis
			3.1.3 Procedure of the Purity Test
			3.1.4 Reporting of Results
			3.1.5 Advanced Equipment for Seed Purity Testing
	4 Seed Moisture Determination
		4.1 Methods of Moisture Determination
			4.1.1 Destructive/Hot Air Oven Method
			4.1.2 Calculation and Expression of Results
			4.1.3 Determination of Moisture Content by Non-destructive/Quick Method
		4.2 Reporting of Results
	5 Germination
		5.1 Seed Germination Stages
		5.2 Types of Seed Germination
			5.2.1 Epigeal Germination
			5.2.2 Hypogeal Germination
		5.3 Germination Testing
			5.3.1 Essential Equipment Required to Conduct Germination Test
			5.3.2 Substrate/Media for Seed Germination
			5.3.3 Germination Test Conditions
			5.3.4 Evaluation of Germination Test
			5.3.5 Evaluation of Seedlings
			5.3.6 Calculation and Expression of the Result
			5.3.7 Retesting
	6 Seed Viability
		6.1 Seed Viability Test
		6.2 Tetrazolium Test
			6.2.1 Procedure
			6.2.2 Evaluation of the Staining Pattern
			6.2.3 Tetrazolium Testing Method for Various Species
	References
Seed Health: Testing and Management
	1 Significance of Seed Health Testing
	2 Seed Sampling
	3 Genesis of Seed Health Testing
		3.1 Advancements in Seed Health Testing Methodologies
			3.1.1 Conventional Methods
				Direct Examination
				Seed Washing Test
				NaOH Seed Soak Method
				Embryo Count Method
				Incubation Test
				Seedling Grow-Out Test
			3.1.2 Immunoassay Methods
			3.1.3 Molecular/Nucleic Acid-Based Diagnostic Methods
	4 Management of Seed-Borne Diseases
		4.1 Management of Seed-Borne Diseases Through Crop Production Practices
			4.1.1 Identification of Disease-Free Areas for Healthy Seed Production
			4.1.2 Time of Sowing
			4.1.3 Cultural Practices
		4.2 Seed Certification for the Management of Seed-Borne Diseases
			4.2.1 Designated Seed-Borne Diseases
		4.3 Management of Seed-Borne Diseases Through Quarantine Regulations
		4.4 Management of Seed-Borne Diseases Through Seed Treatment
			4.4.1 Physical Seed Treatment
			4.4.2 Chemical Seed Treatment
			4.4.3 Biological Seed Treatment
	5 Conclusions
	References
Molecular Techniques for Testing Genetic Purity and Seed Health
	1 Introduction
	2 Variety Characterization/Identification and Genetic Purity Testing
	3 Molecular Markers for Varietal Identity and Genetic Purity
		3.1 Restricted Fragment Length Polymorphism (RFLP)
		3.2 Randomly Amplified Polymorphic DNAs (RAPD)
		3.3 Cleaved Amplified Polymorphic Sequences
		3.4 Amplified Fragment Length Polymorphism (AFLP)
		3.5 Sequence Characterized Amplified Regions (SCAR)
		3.6 Simple Sequence Repeats (SSRs)
		3.7 Multiplex PCR
		3.8 Expressed Sequence Tags (ESTs)
		3.9 Inter Simple Sequence Markers (ISSR)
		3.10 Sequence-Related Amplified Polymorphisms
		3.11 Single Nucleotide Polymorphisms (SNPs)
	4 Use of Molecular Markers for Plant Variety Protection
	5 Transgenic/Genetically Modified Seeds
	6 Methods of GM Seed Testing
		6.1 Lateral Flow Strip Test
		6.2 ELISA (Enzyme-Linked Immunosorbent Assay) Test
		6.3 Bioassays
		6.4 Conventional PCR
		6.5 Real-Time Polymerase Chain Reaction (RT-PCR/qPCR)
	7 ISTA and GM Seed Testing
	8 Molecular Markers in Germplasm Conservation and Maintenance
	9 Molecular Techniques for Seed Health Testing
		9.1 Polymerase Chain Reaction (PCR)
		9.2 Bio-Polymerase Chain Reaction (bio-PCR)
		9.3 Multiplex Polymerase Chain Reaction (mPCR)
		9.4 Nested PCR
		9.5 Real-Time PCR
		9.6 Loop-Mediated Isothermal Amplification (LAMP)
		9.7 Microarray Technology
	10 Challenges in Using Molecular Techniques for Seed Quality Testing
	References
Seed Quality Enhancement
	1 Introduction
		1.1 Scope of Seed Quality Enhancement
			1.1.1 Advantages Expected from Enhancement Techniques
	2 Types of Seed Quality Enhancement
		2.1 Physical Methods
		2.2 Film Coating, Pelleting and Encrusting
		2.3 Seed Treatment for Protection Against Pests and Diseases
		2.4 Physiological Enhancements
			2.4.1 Pre-sowing Priming
			2.4.2 Mid-storage Correction
		2.5 Other Technologies
			2.5.1 IP Protection and Microbranding
	3 Methods of Seed Enhancements
		3.1 Physical Enhancements
			3.1.1 Seed Cleaning, Processing and Quality Upgradation
		3.2 Film Coating
			3.2.1 Advantages of Film Coating
			3.2.2 Trends in Seed Film Coating
		3.3 Seed Pelleting
			3.3.1 Selection of the Pelleting Material
			3.3.2 Advantages of Seed Pelleting
		3.4 Seed Encrustation
		3.5 Hot Water Treatment
		3.6 Steam Treatment
		3.7 Dry Heat Treatment
		3.8 Other Potential Treatments
			3.8.1 Magnetic and Electromagnetic Seed Enhancement Treatment
			3.8.2 Radiation Treatments
			3.8.3 Electron Treatment
	4 Physiological Enhancements
		4.1 Pre-sowing Seed Priming
		4.2 Types of Seed Priming
			4.2.1 Hydropriming
			4.2.2 Osmopriming
			4.2.3 Solid Matrix Priming
			4.2.4 Halopriming
			4.2.5 Biopriming
				Endophytic Association
		4.3 Pre-germination
		4.4 Mid-storage Correction by Hydration-Dehydration
		4.5 Emerging Seed Enhancement Treatments
	5 IP Protection and Microbranding
	6 Conclusion
	References
Emerging Trends and Promising Technologies
	1 Introduction
	2 Hybrid Seed Production
	3 Prediction of Seed Longevity
	4 Seed Germination and Dormancy
	5 Desiccation-Sensitive (Recalcitrant) and Intermediate Longevity Behaviour
	6 Quantifiable, Universal Vigour Tests
	7 Non-destructive Rapid Assessment of Seed Viability/Germination
	8 Imaging Technologies for Quality Assessment
	9 Application of Molecular Markers for Variety Identity and Seed Testing
	10 Next-Generation Seed Enhancement Technology
	References