1. Introduction.- 1.1 Implications of Pollination Mechanisms in Plant Breeding and Crop Production.- 1.1.1 Pollination Mechanisms and Breeding of New Cultivars.- 1.1.2 Pollination Mechanisms and Cultivar Maintenance.- 1.1.3 Pollination Mechanisms and Agricultural Yield.- 1.2 Reproduction in Higher Plants.- 1.2.1 Historical and General Background.- 1.2.1.1 Morphological-Structural Flower Biology.- 1.2.1.2 Functional Flower Biology.- 1.2.1.3 Correlation between Structure and Function.- 1.2.2 Modes of Reproduction.- 1.2.2.1 Sexual Reproduction.- 1.2.2.1.1 Spatial Separation of Sex Organs as an Outbreeding Device.- 1.2.2.1.2 Basic Concepts of Structural Differentiation.- 1.2.2.1.3 Models of Floral Differentiation.- 1.2.2.1.4 Definitions of Sex Types in Flowering Plants.- 1.2.2.1.5 Temporal Separation of Sex Organs as an Outbreeding Device.- 1.2.2.2 Asexual Forms of Reproduction.- 1.2.2.2.1 Asexual Propagules outside the Floral Region.- 1.2.2.2.2 Asexual Propagules within the Floral Region.- 1.2.2.3 Distribution of Modes of Reproduction among Cultivated Plants.- 1.3 Ecology and Dynamics of Pollination.- 1.3.1 Specificity of Flowers and Pollen.- 1.3.2 Pollen-Dispersal Agents.- 1.3.2.1 Biotic Vectors;.- 1.3.2.2 Abiotic Vectors.- 1.3.3 Timing and Climatic Factors in Pollination Dynamics.- 1.3.4 Location and Mass Effects in Pollination Ecology.- 1.3.5 Competition Effects in Pollination Dynamics.- 1.3.6 Determination of the Natural Cross-Pollination Rate (NCP).- 1.3.6.1 Progeny Testing of Dominants.- 1.3.6.2 Progeny Testing of Recessives.- 1.3.6.3 Progeny Testing of Heterozygotes.- 1.3.6.4 Progeny Testing of Recessives and Heterozygotes.- 1.3.7 Artificial Control of Outcrossing.- 2. Autogamy.- 2.1 Evolutionary Aspects of Autogamy.- 2.1.1 Strategies for Adjustment of Recombination.- 2.1.2 Origin of Mating Systems in Higher Plants.- 2.1.3 Variation in Autogamous Populations.- 2.2 Mechanism of Autogamy.- 2.2.1 Cleistogamy.- 2.2.2 Chasmogamic Selfing.- 2.3 Management of Pollination in Autogamous Crops.- 2.3.1 Emasculation.- 2.3.1.1 Mechanical Removal of Microsporophylls.- 2.3.1.2 Male Gametocide.- 2.3.1.3 Circumvention of Emasculation Requirements.- 2.3.2 Controlled Pollination.- 2.3.2.1 Isolation.- 2.3.2.2 Pollen Collection and Storage.- 2.3.2.3 Pollen Transfer Methods.- 2.3.2.3.1 Utilization of Natural Pollen Vectors.- 2.3.2.3.2 Forced Pollination.- 3. Allogamy.- 3.1 Sexual Reproduction — Structures and Functions.- 3.1.1 The Anther and the Male Gametophyte.- 3.1.1.1 Differentiation of the Anther.- 3.1.1.2 TheTapetum.- 3.1.1.3 Development of the Sporogeneous Tissue.- 3.1.1.4 Microsporo genesis.- 3.1.1.5 From Microspore to Pollen Grain.- 3.1.2 Androgenesis: Production of Haploid Plants by Anther and Pollen Culture.- 3.1.2.1 Haploid Plants—Occurrence, Induction, and Identification.- 3.1.2.2 The Production of Haploid Callus and Embryoids by Anther and Pollen Culture.- 3.1.2.3 Pathways of Pollen Embryogenesis.- 3.1.2.4 Factors Affecting Androgenesis.- 3.1.2.4.1 Culture Conditions.- 3.1.2.4.2 Donor Plants.- 3.1.2.4.3 Pollen Age.- 3.1.2.4.4 Anther Stage and Ploidy.- 3.1.2.5 Application of Androgenesis for Breeding and Genetic Studies.- 3.1.3 The Pistil and the Female Gametophyte.- 3.1.3.1 The Pistil.- 3.1.3.2 The Female Gametophyte.- 3.1.4 Fertilization.- 3.1.4.1 Contact between Pollen and Stigma.- 3.1.4.2 Pollen Germination.- 3.1.4.3 Pollen Tube Discharge and Double Fertilization.- 3.1.5 Sexual Reproduction in Conifers.- 3.2 Control and Modification of Sex.- 3.2.1 The Genetic Control of Sex Determination.- 3.2.1.1 General Considerations Concerning the Genetic Control of Dioecism.- 3.2.1.2 Artificial Dioecism in Zea mays.- 3.2.1.3 Artificial Dioecism Caused by Suppressive Genes — Linkage between Genes as a Prerequisite for Sex Dimorphism.- 3.2.1.4 Chromosomal Control of Sex Determination.- 3.2.1.5 Main Methods for the Study of the Genetics and Cytology of Sex Determination.- 3.2.1.6 Genetic Regulation of Sex: Representative Examples.- 3.2.1.6.1 The Active Y Chromosome System.- 3.2.1.6.2 The X-Autosomal Balance System.- 3.2.1.7 Genetics of Sex Determination in Some Economic Crops.- 3.2.2 Modifications of Sex Expression.- 3.2.2.1 Introduction.- 3.2.2.2 Mineral Nutrition and Edaphic Factors.- 3.2.2.3 Light.- 3.2.2.4 Temperature.- 3.2.2.5 Chemical Agents.- 3.2.2.5.1 Auxins and Related Compounds.- 3.2.2.5.2 Gibberellins.- 3.2.2.5.3 Kinins.- 3.2.3 Sex Expression in Some Economic Crops and its Application to Breeding and Crop Improvement.- 3.2.3.1 The Cucumber and Other Cucurbit Crops.- 3.2.3.1.1 Patterns of Sex Expression.- 3.2.3.1.2 Effects of Day Length and Temperature on Flowering and Sex Expression.- 3.2.3.1.3 Effects of Growth Regulators.- 3.2.3.1.4 Inheritance of Sex Expression and Breeding Procedures.- 3.2.3.1.5 Scheme of Sex Expression in Cucumber.- 3.2.3.2 Hemp (Cannabis sativa).- 3.2.3.3 Maize (Zea mays).- 3.2.3.3.1 Reproductive Morphology.- 3.2.3.3.2 Environmentally Induced Sex Modification.- 3.2.3.3.3 Sex Modification by Chemical Agents.- 3.2.3.3.4 Inheritance of Sex Expression.- 3.3 Incompatibility.- 3.3.1 Genetics of Incompatibility.- 3.3.1.1 Gametophytic Incompatibility.- 3.3.1.1.1 One Multiallelic S Locus.- 3.3.1.1.2 Two Multiallelic S Loci.- 3.3.1.1.3 Three or MoreS Loci.- 3.3.1.2 Sporophytic Incompatibility.- 3.3.1.2.1 Heteromorphic Incompatibility.- 3.3.1.2.2 Homomorphic Incompatibility.- 3.3.2 Pollen-Pistil Interaction.- 3.3.2.1 Pollen Cytology and Pollen-Stigma Interaction….- 3.3.2.2 Pollen Tube-Style Interaction.- 3.3.2.3 Pollen Tube-Ovule Interaction.- 3.3.3 Incompatibility, Crop Production, and Breeding.- 3.3.3.1 Transfer of Incompatibility into Cultivars.- 3.3.3.2 Permanent Elimination of Incompatibility.- 3.3.3.3 Surmounting the Incompatibility Barrier.- 3.3.3.3.1 Treatment of Pollen.- 3.3.3.3.2 Bud Pollination.- 3.3.3.3.3 Delayed Pollination.- 3.3.3.3.4 Heat Treatment.- 3.3.3.3.5 Surgical Techniques.- 3.3.3.3.6 Double Fertilization.- 3.3.3.3.7 Other Methods.- 3.3.3.4 Hybrid Seed Production.- 3.3.3.4.1 Characteristics of the Gametophytic and Sporophytic Incompatibility Systems which are Related to Hybrid Seed Production.- 3.3.3.4.2 Hybrid Seed Production in Brassica and Raphanus.- 3.3.3.4.3 Problems in Breeding Aimed at Hybrid Seed Production.- 3.4 Male Sterility.- 3.4.1 Gynodioecy: Male Sterility in Natural and Artificial Populations.- 3.4.1.1 Male Sterility as an Outbreeding Mechanism in Gynodioecious Species.- 3.4.1.2 Nuclear Male Sterility Genes in Cultivars.- 3.4.1.3 Male-Sterility-Inducing Plasmatypes in: Cultivated Plants.- 3.4.1.4 Utilization of Gynodioecy in Plant Breeding.- 3.4.2 Inheritance of Male Sterility.- 3.4.2.1 Genie Male Sterility (Mendelian Male Sterility).- 3.4.2.2 Cytoplasmic and Gene-Cytoplasmic Male Sterility.- 3.4.3 Structural, Developmental, and Biochemical Charac-terization of Male Sterility.- 3.4.3.1 Developmental Modifications Leading to Breakdown in Microgametogenesis.- 3.4.3.1.1 Modifications in the Structural Differentiation of the Stamen.- 3.4.3.1.2 Faulty Differentiation of the Anther.- 3.4.3.1.3 Breakdown in Microsporogenesis.- 3.4.3.1.4 Abortion of the Microgametophyte.- 3.4.3.1.5 Functional Male Sterility.- 3.4.3.2 Biochemistry of Male Sterility.- 3.4.3.3 Male Sterility Genes and Their Action.- 3.4.3.3.1 Site of Male Sterility Factors.- 3.4.3.3.2 Pleiotropic Effects.- 3.4.4 Utilization of Male Sterility in Plant Breeding.- 3.4.4.1 Comparison of Hybrid Production Using Genie, Cytoplasmic and Gene-Cytoplasmic Male Sterility.- 3.4.4.1.1 Genie Male Sterility.- 3.4.4.1.2 Cytoplasmic Male Sterility.- 3.4.4.1.3 Gene-Cytoplasmic Male Sterility.- 3.4.4.2 Application of Genie Male Sterility.- 3.4.4.2.1 Genetic and Field Management Programs to Provide a Homogeneous Stand of the Genie Male Sterile Seed Parent.- 3.4.4.2.2 Pollination Control.- 3.4.4.3 Use of Gene-Cytoplasmic Male Sterility.- References.