Cytogenetics in Plant Breeding

An introductory discussion of basic chromosome structure and function preceeds the main text on the application of cytogenetic approaches to the analysis of the manipulation of both the genetic make-up and the genetic transmission system of plant breeding material. Analysis using light and electron microscopy, segregations and molecular techniques, yields information for assessing the material before and after manipulation. Much attention is given to quantitative methods. Manipulation not only involves the construction of specific genotypes, but also chromosomal transmission systems. Although analysis and manipulation in the somatic cycle are considered, the focus is on the generative cycle, with emphasis on analysis and subsequent segregation of specifically constructed material. The book is intended for plant breeders and other scientists interested in the analysis and manipulation of breeding material at the chromosomal level. Comparisons with molecular and cell biological approaches are made, and the potential of the various methods is evaluated.

Contenu

1 Cytogenetics in Genetics and Plant Breeding.- 1.1 Cytogenetics as a Subdiscipline of Genetics.- 1.1.1 The Two Functions of the Genetic Material.- 1.1.2 Cytogenetics Defined.- 1.2 Cytogenetics in Plant Breeding.- 2 Chromosome Composition, Structure and Morphology.- 2.1 DNA.- 2.1.1 The Chemical Basis.- 2.1.2 Heterogeneity of DNA; Unique and Repetitive DNA.- 2.1.3 Replication.- 2.2 Chromosome Structure; Histones and Other Chromosomal Proteins.- 2.3 Euchromatin, Heterochromatin.- 2.4 Special Functional Elements in Chromosomes.- 2.4.1 Nucleolus Organizing Region (NOR).- 2.4.2 Centromere.- 2.4.3 Telomeres.- 2.5 Microscopic Chromosome Morphology: the Karyotype, Standard and Variations.- 3 The Mechanisms of Genetic Transmission.- 3.1 The Somatic Cycle.- 3.1.1 Mitosis.- 3.1.2 Duration of Mitosis.- 3.1.3 Order and Disorder in the Somatic Spindle and Nucleus.- 3.1.3.1 Relative Position of Large and Small Chromosomes in the Spindle and in the Nucleus. Hollow Spindle.- 3.1.3.2 Rabl Orientation.- 3.1.3.1 Nucleolar Fusion.- 3.1.3.2 Somatic Pairing.- 3.1.3.3 Non-homologous Chromosome Association; Nuclear Compartmentalization.- 3.1.4 Mitotic Variants with Genetic Consequences.- 3.1.4.1 Intact Organism.- 3.1.4.1.1 Accidents.- 3.1.4.1.2 Systematic Deviations.- 3.1.4.1.2.1 Chromosome Doubling.- 3.1.4.1.2.2 Elimination.- 3.1.4.1.2.3 B-Chromosomes.- 3.1.4.2 In Vitro Culture.- 3.2 Generative Transmission: Fertilization - Meiosis.- 3.2.1 Fertilization.- 3.2.2 Meiosis.- 3.2.2.1 Prophase I.- 3.2.2.2 Metaphase 1.- 3.2.2.3 Anaphase I, Telophase I.- 3.2.2.4 Meiosis II.- 3.2.3 Systematic Variants of Meiotic Behaviour.- 3.2.3.1 Achiasmate Meiosis.- 3.2.3.2 Holokinetic Chromosomes.- 3.2.3.3 Neocentric Activity.- 3.2.3.4 Specialized Chromosomes.- 3.2.4 Recombination.- 3.2.4.1 Two Forms of Recombination.- 3.2.4.1.1 Chromosome Recombination.- 3.2.4.1.2 Exchange Recombination.- 3.2.4.1.2.1 Two and More Chiasmata in One Chromosome.- 3.2.4.1.2.2 Genetic Variation in Exchange Recombination.- 3.2.4.1.2.2.1 Genetic Variation in Frequency of Exchange.- 3.2.4.1.2.2.2 Genetic Variation in Pattern of Exchange.- 4 The Somatic Chromosome Complement: Karyotype Analysis.- 4.1 The Karyotype.- 4.1.1 Characteristics of the Karyotype.- 4.1.2 Applications of Karyotype Analysis.- 4.2 Approaches to Karyotype Analysis: Chromosome Number and Morphology.- 4.2.1 Number of Genomes Per Cell: Indirect Methods.- 4.2.2 Exact Chromosome Number; Chromosome Morphology.- 4.2.2.1 Techniques of Preparation.- 4.2.2.2 Observations; Measurements.- 4.2.1 Presenting the Karyotype.- 4.2.3.1 Karyogram and Idiogram.- 4.2.3.2 Idiogram Construction: Coping with Variation.- 4.2.3.3 Idiogram Construction: Plotting the Observations.- 4.2.2 Markers Within Chromosome Arms.- 4.2.4.1 Chromosome Banding.- 4.2.4.2 Molecular Markers.- 4.2.4.3 Genetic Markers.- 5 Karyotype Variants A: Chromosome Structural Variants.- 5.1 Deficiencies.- 5.1.1 Types.- 5.1.2 Origin.- 5.1.3 Relevance.- 5.1.4 Characteristics and Identification.- 5.1.5 Consequences.- 5.2 Duplications.- 5.2.1 Types.- 5.2.2 Origin.- 5.2.3 Relevance.- 5.2.4 Characteristics and Identification.- 5.2.5 Consequences.- 5.3 Inversions Ill.- 5.3.1 Types (Paracentric and Pericentric) and Origin Ill.- 5.3.2 Relevance Ill.- 5.3.3 Characteristics and Identification Ill.- 5.3.4 Consequences.- 5.4 Translocations.- 5.4.1 Reciprocal Translocation or Interchange and Simple Terminal Translocation.- 5.4.1.1 Types and Origin.- 5.4.1.2 Relevance.- 5.4.1.3 Characteristics and Identification.- 5.4.1.4 Consequences.- 5.4.2 Two or More Interchanges Combined: Translocation Tester Set; Balanced Complex Translocation Heterozygotes.- 5.4.2.1 Types and Origin.- 5.4.2.2 Relevance.- 5.4.2.3 Characteristics and Identification.- 5.4.2.4 Consequences.- 5.4.3 Simple Interstitial Translocations.- 1.2.1.1 Types, Origin and Relevance.- 1.2.1.2 Characteristics, Identification and Consequences.- 5.5 Other Rearrangements (Robertsonian Fission and Fusion; Isochromosome; Compound).- 5.5.1 Types and Origin.- 5.5.2 Relevance.- 5.5.3 Characteristics, Identification and Consequences.- 6 Karyotype Variants B: Chromosome Number Variants.- 6.1 Euploidy.- 6.1.1 Haploidy.- 6.1.1.1 Types and Terminology.- 6.1.1.2 Origin.- 6.1.1.3 Relevance.- 6.1.1.4 Characteristics and Identification.- 6.1.1.5 Consequences.- 6.1.2 Polyploidy.- 6.1.2.1 Types.- 6.1.2.2 Autopolyploidy; Types.- 6.1.2.2.1 Autotriploids.- 6.1.2.2.1.1 Origin.- 6.1.2.2.1.2 Relevance.- 6.1.2.2.1.3 Characteristics and Identification.- 6.1.2.2.1.4 Consequences.- 6.1.2.2.2 Autotetraploids.- 6.1.2.2.2.1 Origin.- 6.1.2.2.2.2 Relevance.- 6.1.2.2.2.3 Characteristics and Identification.- 6.1.2.2.2.4 Consequences.- 6.1.2.2.3 Higher Autopolyploids.- 6.1.2.3 Allopolyploidy.- 6.1.2.3.1 Types.- 6.1.2.3.2 Origin.- 6.1.2.3.3 Relevance.- 6.1.2.3.4 Characteristics and Identification.- 6.1.2.3.5 Consequences.- 6.1.2.4 Polyploid Hybrids.- 6.1.2.4.1 Types, Origin and Relevance.- 6.1.2.4.2 Characteristics, Identification and Consequences.- 6.2 Aneuploidy.- 6.2.1 Hypoploidy, Monosomy.- 6.2.1.1 Types of Monosomy.- 6.2.1.2 Origin.- 6.2.1.1 Relevance.- 6.2.1.2 Characteristics and Identification.- 6.2.1.3 Consequences.- 6.2.2 Hyperploidy.- 6.2.2.1 Primary Trisomy.- 6.2.2.1.1 Types.- 6.2.2.1.2 Origin.- 6.2.2.1.3 Relevance.- 6.2.2.1.4 Characteristics and Identification.- 6.2.2.1.5 Consequences.- 6.2.2.2 Secondary and Telocentric Trisomy.- 6.2.2.2.1 Types, Origin.- 6.2.2.2.2 Relevance.- 6.2.2.2.3 Characteristics and Identification.- 6.2.2.2.4 Consequences.- 6.2.2.3 Tertiary and Translocation Trisomy.- 6.2.2.3.1 Types, Origin.- 6.2.2.3.2 Relevance.- 6.2.2.3.3 Characteristics and Identification.- 6.2.2.3.4 Consequences.- 6.2.2.4 Other Trisomies and Higher Polysomies.- 6.2.2.4.1 Compensating Trisomies.- 6.2.2.4.2 Alien Additions.- 6.2.2.4.2.1 Types, Origin.- 6.2.2.4.2.2 Relevance.- 6.2.2.4.2.3 Characteristics, Identification and Consequences.- 7 Diagnosis: Identifying Cytogenetic Causes of Variants of the Karyotype and the Generative Cycle.- 7.1 Diagnosis: The Collection of Specific Information: Context, Objectives and Means.- 7.2 The Diagnostic Strategy.- 7.3 The Diagnostic Use of Meiotic Behaviour and Configurations: Types and Distribution;Causes and Consequences.- 7.3.1 Stages.- 7.3.2 Basic Configuration.- 7.3.3 Distribution of Configurations.- 7.4 The Diagnostic Protocol.- 7.4.1 No Chromosome Number Deviation.- 7.4.1.1 Meiosis: Diakinesis/Metaphase I: No Obvious Deviations.- 7.4.1.2 Univalents.- 7.4.1.1 Heteromorphic or Otherwise Abnormal Bivalents.- 7.4.1.2 Multivalents.- 7.4.1.4.1 Trivalents.- 7.4.1.4.2 Quadrivalents: Chromosome Number Normal; Karyotype Visibly Changed.- 7.4.1.4.3 Higher-Order Multivalents; Chromosome Number Normal, Chromosome Structure Normal or Deviant.- 7.4.1.3 Chromosome Number Normal; Diakinesis-Metaphase I Normal.- 7.4.1.5.1 Unequal Sister Chromatids.- 7.4.1.5.2 Chromatid Bridges.- 7.4.1.5.3 Chromatid Loops.…