Cytogenetics of the Festuca-Lolium Complex

Chromosomes.-7.1 Occurrence and Adaptive Value.- 7.2 Pairing Among B Chromosomes in Hexaploid Tall Fescue.- 7.3 Effect on Genetic Recombination.- 7.4 Suppression of Homoeologous Pairing in Hybrids.- 7.5 B Chromosomes in Relation to Plant Breeding.- 8 Natural and Induced Polyploidy.- 8.1 Natural Polyploidy and Its Adaptive Value in Festuca.- 8.2 Absence of Natural Polyploidy in Lolium.- 8.3 Induced Polyploidy in Lolium.- 8.4 Distinguishing Features of Synthetic Polyploids of Lolium.- 8.5 Induced Polyploidy in Festuca.- 8.6 Occurrence of Aneuploids in Synthetic Polyploids.- 8.7 Polyploidy in Relation to Plant Breeding.- 9 Haploidy.- 9.1 Lolium Haploids.- 9.2 Festuca Haploids.- 10 Aneuploids.- 10.1 Lolium.- 10.2 Hexaploid Tall Fescue.- 11 Intra- and Inter-Specific Hybridization, Genome Relationships, and Plant Improvement.- 11.1 General Importance.- 11.2 Crossing Techniques.- 11.3 The Embryo Rescue Technique.- 11.4 Extensive Hybridization Work.- 11.5 General Meiotic Abnormalities in Wide Hybrids.- 11.6 Phylogenetic Proximity Among Species of the Lolium-Festuca Complex: a Generalized Picture.- 11.7 Intraspecific Hybrids in Lolium L.- 11.8 Intraspecific Hybrids in Festuca L..- 11.9 Interspecific Hybrids in Lolium.- 11.10 Hybrids Between the Two Ryegrasses: Development of Superior Germplasm.- 11.11 Interspecific Hybrids in Festuca.- 11.12 F. arundinacea (6x) x F. gigantea (6x) Hybridization: Development of Superior Germplasm.- 12 Intergeneric Hybridization, Genome Relationships, and Plant Improvement.- 12.1 Possible Affinity Between Festuca and Other Grass Genera.- 12.2 General Affinities Between Lolium and Festuca.- 12.3 Natural Hybrids.- 12.4 Synthetic Hybrids.- 12.5 Variation in Chromosome Size Between Diploid Species and Pairing in Their Hybrids.- 12.6 Intergeneric Hybridization and Production of Superior Breeding Material.- 13 Genomic Balance in Relation to Hybrid Fertility and Plant Improvement.- 13.1 Width of the Cross and Crossing Success.- 13.2 Choice of Parents.- 13.3 Choiceof Female Parent.- 13.4 Genomic Constitution and Hybrid Fertility.- 14 Biotechnology in Festuca-Lolium Improvement.- 14.1 General Scope and Importance: Genetic Engineering.- 14.2 Meristem-Tip Culture: a Method to Eliminate Pathogens.- 14.3 In Vitro Callus Cultures and Screening for Tall Fescue Endophyte.- 14.4 Organogenesis and Embryogenesis.- 14.5 In Vitro Cultures and Plant Regeneration.- 14.6 Anther Culture.- 14.7 Somaclonal and Gametoclonal Variation.- 14.8 Colchicine-Induced Variation.- 14.9 Environmentally Induced Somatic Variation.- 14.10 Cytogenetic Manipulation of Hybrid Material.- 14.11 In Vitro Chromosome Doubling.- 14.12 Protoplast Cultures: Regeneration of Plants.- 14.13 Genetic Manipulation at the Cellular Level.- 15 Conclusions and Perspectives.- References.