This book is based mainly on invited and offered papers presented at the Second International Symposium on Bacterial and Bacteria-like Contaminants of Plant Tissue Cultures held at University College, Cork, Ireland in September 1996, with additional invited papers. The First International Symposium on Bacterial and Bacteria-like Contaminants of Plant Tissue Cultures was held at the same venue in 1987 and was published as Acta Horticulturae volume 225, 1988. In the intervening years there have been considerable advances in both plant disease diagnostics and in the development of structured approaches to the management of disease and microbial contamination in micropropagation. These approaches have centred on attempts to separate, spatially, the problems of disease transmission and laboratory contamination. Disease-control is best achieved by establishing pathogen-free cultures while laboratory contamination is based on subsequent good working practice. Control of losses due to pathogens and microbial contamination in vitro addresses, arguably, the most importance causes of losses in the industry; nevertheless, losses at and post establishment can also be considerable due to poor quality microplants or micro-shoots. In this symposium, a holistic approach to pathogen and microbial contamination control is evident with the recognition that micropropagators must address pathogen and microbial contamination in vitro, and diseases and microplant failure at establishment. There is increasing interest in establishing beneficial bacterial and mycorrhizal association with microplants in vitro and in vivo.

Inhalt
Overview.- Pathogen and microbial contamination management in micropropagation an overview.- Strategic considerations for the establishment of micro-organism-free tissue cultures for commercial ornamental micropropagation.- Improved virus detection in rosaceous fruit trees in vitro.- Trends in European plant tissue culture industry from 1990 to 1993.- Commercial micropropagation laboratories in the United States.- Pathogen and Contaminant Detection and Identification.- Walled and wall-less Eubacteria from plants: sieve-tube-restricted plant pathogens.- Modern methods for identifying bacteria.- Developments in serological methods to detect and identify plant viruses.- Molecular diagnostics for pathogen detection in seeds and planting material.- Isolation and analysis of double-stranded RNA in plant tissues to detect virus and virus-like agents.- A review of the lux-marker system: potential for application in plant tissue culture.- DNA profiling and strategies for in planta localization of bacteria intimately associated with Billbergia magnifica ssp. acutisepalia.- Cost analysis of detection of bacteria and phytoplasmas in plant tissue cultures by PCR.- Microbes intimately associated with tissue and cell cultures of tropical Dioscorea yams.- Detection and identification of bacterial contaminants of strawberry runner explants.- Evidence for the occurrence of endophytic prokaryotic contaminants in micropropagated plantlets of Prunus cerasus cv. 'Montmorency'.- Occurrence and influence of endogenous bacteria in embryogenic cultures of Norway spruce.- Chemotherapy and Thermotherapy of Plants and Cultures.- Antibiotics in plant tissue culture and micropropagation what are we aiming at?.- Elimination of external and internal contaminants in rhizomes of Zantedeschiaaethiopica with commercial fungicides and antibiotics.- Internal bacterial contamination of micropropagated hazelnut: identification and antibiotic treatment.- Elimination of several bacterial isolates from meristem tips of Hydrangea spp.- The application of antibiotics and sulphonamide for eliminating Bacillus cereus during the micropropagation of infected Dieffenbachia picta Schott.- Identification and antibiotic sensitivity of bacterial contaminants isolated from in vitro cultures of some tropical aquatic plants.- The effect of acetylsalicylic acid on development of bacterial contaminants and gas evolution in apricot shoot cultures.- Control of Bacillus contaminating date palm tissue in micropropagation using antibiotics.- Monitoring of virus diseases in Austrian grapevine varieties and virus elimination using in vitro thermotherapy.- Hot-water treatment before tissue culture reduces initial contamination in Lilium and Acer.- Elimination of bean seed-borne bacteria by thermotherapy and meristem culture.- Prevention and elimination of contamination for in vitro culture of several woody species.- Laboratory Contamination Management.- Laboratory contamination management; the requirement for microbiological quality assurance.- Microbial communities on human tissue: an important source of contaminants in plant tissue cultures.- Contamination by micro-arthropods in plant tissue cultures.- Photoautotrophic micropropagation a strategy for contamination control?.- The use of Hortifoam substrate in a micropropagation system. Comparative study of sugar-based and sugar-free medium.- Plant tissue culture laboratory establishment under challenging conditions.- In vitro callus formation on watermelon cotyledon explants is influenced by the presence of endophytic organisms.-Disease at Microplant Establishment.- Epiphytic bacteria: activities, risks and benefits.- Fungal infections of micropropagated plants at weaning: a problem exemplified by downy mildew in Rubus and Rosa.- From laboratory to applications: challenges and progress with in vitro dual cultures of potato and beneficial bacteria.- Bacillus subtilis an endophyte of Chestnut (Castanea sativa) as an antagonist against Chestnut Blight (Cryphonectria parasitica).- Biological control of Botrytis, Phytophthora and Pythium by Bacillus Subtilis Cot1 and CL27 of micropropagated plants in high-humidity fogging glasshouses.- Microbial characterisation and preparation of inoculum for in vitro mycorrhization of strawberry in autotrophic culture.- Acclimation results of micropropagated Black Locust (Robinia pseudoacacia L.) improved by symbiotic microorganisms.- A review of tissue proliferation of Rhododendron.- Problems with plant health of in vitro propagated Anthurium spp. and Phalaenopsis hybrids.