Collecting, conservation and utiklization of plant genetic resources and their global distribution are essential componentes of international crop improvement programmes. Inevitably, the movement of germplasm involves a risk of accidentally introducing plant quarantine pests*along with the host plant material; in particular, pathogens that are often symptomless, such as viruses, pose a special risk. In order to minimize this risk, effective testing (indexing) procedures are required toensure that distributed material is free of pests that are of quarantine concern. The ever-incrrrreasing volume of germplasm exchanged internationally, coupled with recent rapid advances in biotechnology, has created a pressing need for crop-specific overviews of the existing kno.

The technical guidelines are written in a short, direct, sometimes telegraphic style, in order to keep the volume of the document to a minimum and to facilitate updating. The guidelines are divided into two parts. The first part makes general recommendations on how best to move germplasm of the crop concerned and mentions available intermediate quarentine facilities when relevant. The second part covers the important pests and diseases of quarentine concern. The information given on a particular pest or disease does not pretend to be exhaustive but concentrates on those aspects that are most relevante to quarentine. Where possible, acronyms for viruses are according to Hull et. al (1991).

Fruit Breeding is the eighth volume in the Handbook of Plant Breeding series. Like the other volumes in the series, this volume presents information on the latest scientific information in applied plant breeding using the current advances in the field, from an efficient use of genetic resources to the impact of biotechnology in plant breeding. The majority of the volume showcases individual crops, complemented by sections dealing with important aspects of fruit breeding as trends, marketing and protection of new varieties, health benefits of fruits and new crops in the horizon. The book also features contributions from outstanding scientists for each crop species. Maria Luisa Badenes Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain David Byrne Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA