Micropropagation “… the art and science of multiplying plants in vitro.”

Clone Genetically identical assemblage of individuals propagated entirely by vegetative means from a single plant. Clone Genetically identical assemblage of individuals propagated entirely by vegetative means from a single plant.

Explant Cell, tissue or organ of a plant that is used to start in vitro cultures. Explant Cell, tissue or organ of a plant that is used to start in vitro cultures.

Axillary shoot proliferation Growth of axillary buds stimulated by cytokinin treatment; shoots arise mostly from pre-existing meristems. Axillary shoot proliferation Growth of axillary buds stimulated by cytokinin treatment; shoots arise mostly from pre-existing meristems.

Shoot proliferating culture of ‘Hally Jolivette’ cherry

Fungal contamination in rhododendron culture

Rhododendron cultures in the lab of Herman Losely & Son Nursery, Perry, OH

Amelanchier laevis transplants and field planting.

Micropropagation Advantages Micropropagation Advantages From one to many propagules rapidlyFrom one to many propagules rapidly Multiplication in controlled lab conditionsMultiplication in controlled lab conditions Continuous propagation year roundContinuous propagation year round Potential for disease-free propagulesPotential for disease-free propagules

Conventional Propagation Advantages Conventional Propagation Advantages Equipment costs minimalEquipment costs minimal Experience can substitute for technical expertiseExperience can substitute for technical expertise Costs per unit are minimalCosts per unit are minimal Potential for disease-free propagulesPotential for disease-free propagules Specialized techniques for growth control (grafting onto dwarfing rootstocks)Specialized techniques for growth control (grafting onto dwarfing rootstocks)

Micropropagation Limitations Micropropagation Limitations Equipment/facility intensive operationEquipment/facility intensive operation Technical expertise in management positionsTechnical expertise in management positions Protocols not optimized for all speciesProtocols not optimized for all species Liners may not fit industry standardLiners may not fit industry standard Propagules may be too expensivePropagules may be too expensive

Micropropagation Applications Micropropagation Applications Rapid build up of stock of new, superior varietyRapid build up of stock of new, superior variety Elimination of endophytic diseaseElimination of endophytic disease Better suited to morphology/growth characteristics (few offshoots/sprouts; date palms, ferns, nandinas)Better suited to morphology/growth characteristics (few offshoots/sprouts; date palms, ferns, nandinas) Propagules have enhanced growth features (multibranched character; Ficus, Syngonium)Propagules have enhanced growth features (multibranched character; Ficus, Syngonium)

Shoot organogenesis Adventitious meristems differentiate on leaf, stem, or floral tissue. Shoot organogenesis Adventitious meristems differentiate on leaf, stem, or floral tissue.

African violet culture started from leaf section.

Begonia x chiemanta ‘Emma’ at various stages in micropropagation.

Somatic Embryogenesis Stimulation of callus or suspension cells to undergo a developmental pathway that mimics the development of the zygotic embryo. Somatic Embryogenesis Stimulation of callus or suspension cells to undergo a developmental pathway that mimics the development of the zygotic embryo.

Somatic Hybridization Fusion of protoplasts from different genotypes to bring about genetic recombination. Somatic Hybridization Fusion of protoplasts from different genotypes to bring about genetic recombination.

Somaclonal variation Heritable genetic variation that arises in plants produced through tissue culture. Somaclonal variation Heritable genetic variation that arises in plants produced through tissue culture.

Chimera Plant composed of two genotypes growing adjacent to one another in all (or part) of the plant body. Chimera Plant composed of two genotypes growing adjacent to one another in all (or part) of the plant body.

Inflorescence culture The inflorescence of many plants is a modified branching system. Vegetative meristems in the inflorescence may be stimulated to proliferate in vitro. Inflorescence culture The inflorescence of many plants is a modified branching system. Vegetative meristems in the inflorescence may be stimulated to proliferate in vitro. bract flower bud peduncle axil