The International Energy Agency Bioenergy Agreement was initiated as the Forestry Energy Agreement in 1978. It was expanded in 1986 to form the Bioenergy Agreement. Since that time the Agreement has thrived with some fifteen countries (Austria, Belgium, Canada, Denmark, Finland, Italy, Japan, Netherlands, New Zealand, Norway, Sweden, Switzerland, United Kingdom, United States and the CEC) currently being signatories. The objective of the Agreement is to establish increased programme and project cooperation between the participants in the field of bioenergy. The environmental consequences of intensive forest harvesting have been the subject of intense interest for the Agreement from its initiation. This interest was formulated as a Cooperative Project under the Forestry Energy Agreement in 1984. It developed further under each of the subsequent three-year Tasks of the Bioenergy Agreement (Task III, Activity 3 "Nutritional consequences of intensive forest harvesting on site productivity," Task VI, Activity 6 "Environmental impacts of harvesting" and more recently Task IX, Activity 4 "Environmental impacts of intensive harvesting." The work has been supported by five main countries from within the Bioenergy Agreement: Canada, New Zealand, Sweden, UK, and USA. The continued work has resulted in a significant network of scientists work ing together towards a common objective - that of generating a better under standing of the processes involved in nutrient cycling and the development of management regimes which will maintain or enhance long term site productivity."

Forests comprise the greatest storage of carbon on land, provide fuel for millions, are the habitat for most terrestrial biodiversity, and are critical to the economies of many countries. Yet changes in the extent and dynamics of forests are inherently difficult to detect and quantify. Remote sensing technologies may facilitate the measurement of some key forest properties which, when combined with other information contained in various computer models, may allow for the quantification of critical forest functions. This book explores how remote sensing and computer modeling can be combined to estimate changes in the carbon storage, or productivity, of forests - from the level of the leaf to the level of the globe. Land managers, researchers, policy makers and students will all find stimulating discussions among an international set of experts at the cutting edge of the interface between science, technology and management.

This volume presents a body of research conducted over more than thirty years, including an intensive interdisciplinary five-year study begun in 1991. Chapters include studies of the relationships of biogeography and climate to the region's air pollution, the chemical and physiological mechanisms of ozone injury, as well as the impacts of nitrogen-containing pollutants and natural stresses on polluted forests.

This book was developed from the proceedings of the American Chemical Society, Division of Agricultural & Food Chemistry, subdivision of Natural Products Symposium "Biosynthesis and Metabolism of Secondary Natural Products" held in Atlanta, Georgia, April 1991. The objective of the conference was to bring together people from apparently diverse fields, ranging from biotechnology, metabolism, mechanistic organic chemistry, enzymology, fermentation, and biosynthesis, but who share a common interest in either the biosynthesis or the metabolism of natural products. It is our intention to help bridge the gap between the fields of mechanistic bio-organic chemistry and biotechnology. Our thanks go to Dr. Henry Yokoyama, co-organizer of the symposium, the authors who so kindly contributed chapters, the conference participants, and to those who assisted in the peer review process. We also thank the financial supporters of the symposium: ACS/AGFD, NIH General Medical Sciences, and the agricultural, pharmaceutical, biotechnology, and chromatography companies. A full list of the supporting corporations and institutions is given on the following page. Pharma-Tech and P.C., Inc. are manufacturers of instrumentation for high-speed countercurrent chromatography. We thank the Agricultural Research Service and the U. S. Department of Agriculture for granting me permission to co-organize the conference and for us to complete the book. Richard J. Petroski Susan P. McCormick USDA, ARS, National Center for Agricultural Utilization Research Peoria, IL 61604 June 10, 1992 vii CONTENTS ANTIBIOTICS Polyketide Synthetases: Enzyme Complexes and Multifunctional Proteins Directing the Biosynthesis of Bacterial Metabolites from Fatty Acids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . .

For the last two decades the loss of, in particular, tropical rainforest has alarmed the public in the developed parts of the world. The debate has been characterised by a lack of understand ing of the causes and effects of the process, leading to the prevailing reaction being unquali fied condemnation. Such attitude has even been observed among scientists, claiming suprem acy to biodiversity conservation. Many scientific analyses are available, but the basis for so ber debates and appropriate actions is still highly insufficient. Two recent international initia tives! will hopefully lead to improved knowledge of deforestation and forest degradation as they recognise the need for studies to critically investigate those issues. This book will pro vide useful input to the initiatives. In my opinion, the scientific analyses have not sufficiently promoted the understanding that the fate of tropical forests is first and foremost a concern of the governments of the countries in which the forests are situated. Tropical forests may be important to the global environment and their rich biodiversity may be a human heritage. But their main importance is their poten tial contribution to improving livelihood in the countries in question.

The 23rd annual meeting of the International Society on Oxygen Transport to Tissue took place from August 23-27, 1995, at the Station Square Sheraton along the shores of the Monongahela River where it meets with the Allegheny and Ohio Rivers to form the "Point" of the city of Pittsburgh. Pittsburgh was a convenient location for the meeting be ing between both the East and West coasts of the United States and between the Asian and European continents. It is easily accessible by air via its large international airport. In ad dition, Pittsburgh has just recently undergone a transition from the steel mills and indus tries of old to an age of computers and biotechnology as evidenced by the new Biotechnology Center of the University of Pittsburgh where a lunch and tour were pro vided for interested participants. On the tour, the participants got to see the mix of projects ranging from molecular biology to clinical projects studying membrane oxygenators, ven tricular assist devices, oxygen carriers, and more, representing the forefront of research on oxygen delivery systems to tissue.

Genetic Engineering, Volume 24 contains discussions of contemporary and relevant topics in genetics, including: -Gene silencing: principles and applications, -Integrins and the myocardium, -Plant virus gene vectors: biotechnology and applications in agriculture and medicine, -Novel approaches to controlling transcription, -Use of DNA polymorphisms in genetic mapping, -Application of FLP/FRT site-specific DNA recombination system in plants. This principles and methods approach to genetics and genetic engineering is essential reading for all academics, bench scientists, and industry professionals wishing to take advantage of the latest and greatest in this continuously emerging field.

Introduced to the technical aspects of forestry aerial spraying in the mid-1970's, we were immediately impressed by the complexity of the process of delivering pesticide to foliage. At that time, there was a vigorous public debate in New Brunswick about the ecological and public h~alth impacts of the annual spray program for the control of defoliation of spruce and fir trees by the spruce budworm. The forest industry is important to the province and changes to the established procedures of budworm control could have major economic implications. A rational debate required reliable information about the mechanics of the spraying process. There was a need to supply missing information as to required pesticide application rates, atomizer performance, off-target drift and deposit, and the effects of weather and aircraft operating factors. We were invited to initiate a research program in this domain by New Brunswick forest management officials, and what follows in this book is a logical and quantitative description of the overall process based on our own research and that of others over the intervening years. After a short introduction to aerial spraying, we begin (Chapter 2) by describing forest stands in terms of their interaction with suspended atmospheric particulate material carried along by the wind and susceptible to deposition on foliage. We introduce foliage simulators and their use in measuring the deposit of sprayed pesticide on foliage, the "biological interface" between pest and pesticide.

With the emergence of urban and community forestry as the fastest growing part of our pro fession in the last 15 years, the need for a book such as this inevitably developed. The So ciety of American Foresters' urban forestry working group counts 32 or more universities now offering courses in this subject, and the number is growing. For the last several years I have coordinated a continuing education urban forestry course at Rutgers for nonmatriculated students. Registrants have included arborists, shade tree commissioners, landscape architects, city foresters, environmental commissioners, park superintendents, and others whose jobs involve care and management of trees. The course was started by Bob Tate in 1980, around a core of managerial subjects such as in ventories, budgets, and public relations. After Bob left in 1984 to join Asplundh and later to start his own prosperous business in California, the course languished after it exhausted the local market for those subjects.

There has been tremendous progress in the genetic transformation of agricultural crops, and plants resistant to insects, herbicides, and diseases have been produced, field tested, and patented. This book compiles this information on various fruits and vegetables.

Recent advances in our understanding of the fundamental role of bioactive lipids in normal and abnormal physiology was the theme of the XVlth International Spring Sympo- 6-9, 1996 at the George Washington University School sium on Health Sciences held on May of Medicine in Washington, D.C. Over 250 participants shared their latest findings on fundamental mechanisms in lipid metabolism, transport, and signal transduction. Most of the papers presented at the plenary sessions have been collected in this volume, which is divided into seven parts. The focus of Part I is on the new roles that fatty acids and esters play in cellular function. These activities include regulation of gene expression, control of eicosanoid-me- diated responses, and intracellular calcium sequestration. Most biological effects of fatty acids, esters, and phospholipids are transmitted via the interaction of these lipid molecules with specific lipid binding proteins. The chapters in Part II detail the involvement of these in the transport of fatty acids, fatty acyl CoA esters, and phospholipids, and in the proteins modulation of the fatty acid-induced activation of the peroxisome proliferator-activated receptors. The study of arachidonic acid metabolism continues to be the subject of intense interest and research. A number of studies in Part III deal with the substantial differences between the constitutive prostaglandin H synthase isozyme (PGHS-l or COX-I) and the inducible form PGHS-2 (COX-2) regarding compartmentation, control, and expression.

Morphometrical differentiation 63 Prediction of breeding origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Body mass 69 Primary moult 69 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 The taxonomy of the Eurasian Golden Plover 69 The existence of a partial breast-feather moult during breeding 69 Morphometrical differentiation between both sexes . . . . . . . . . . . . . . . . . . . . . . . . 70 The occurrence of primary moult on the breeding grounds 70 Summary 70 6 Grey Plover - Pluvialis squatarola 71 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Morphometrical differentiation 77 Prediction of breeding origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Accuracy 81 Exclusivity 81 Contact zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Body mass 85 Primary moult 85 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 The taxonomy of the Grey Plover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Small size at northern latitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Morphometrical variation in the Palearctic 87 Summary 87 7 Red Knot - Calidris canutus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Morphometrical differentiation 93 Prediction of breeding origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Accuracy 99 Exclusivity 101 Contact zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Body mass 102 Primary moult 103 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 of the Knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 The taxonomy Is the knot breeding in Yakutia? 106 Different degrees of geographical variation in the d'd' and !f!f 106 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 8 Sanderling - Calidris alba 109 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Morphometrical differentiation 111 Prediction of breeding origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Accuracy 116 Exclusivity 118 Contact zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Body mass 118 Primary moult 118 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 The taxonomy of the Sanderling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Sexing Sanderlings 119 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 VI 9 Curlew Sandpiper - Calidris ferruginea 121 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Morphometrical differentiation 123 Prediction of a bird's sex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Accuracy 127 Exclusivity 127 Body mass 127 Primary moult 127 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 The taxonomy of the Curlew Sandpiper 127 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Microbiology may be described as one of the younger sciences with its history, as a precise subject, only dating as far back as Pasteur in the mid 1800s and his revelation both of the role of microorganisms in nature and their importance to human welfare. Medical scientists rapidly took up the challenge, with their area of microbiology flourishing and expanding almost in complete isolation from the rest of biology. We now know, of course, that microorganisms have always played an important, if not essential role, in the biosphere with fermented foods and beverages, plant and animal diseases and nutrient cycling foremost in their sphere of activities. Within the last twenty years, microbiology has received two enormous boosts with the developments in microbial genetics and genetic engineering probably being the most influential, and the greater awareness of pollution and environmental sustainability following a close second. In 1990, your editor had the privilege and pleasure of being elected as President of The Association of Applied Biologists in the United King dom and, as the topic for his three-day Presidential Conference, chose 'The exploitation of microorganisms in applied biology'. This meeting stimu lated great interest in a wide range of subject areas, from weed control to nematology, from plant breeding to plant pathology, from mushrooms to mycorrhiza. The proceedings of this meeting were published in Aspects of Applied Biology, No. 24, 1990."

Comprising 26 chapters, this volume deals with the genetic transformation of medicinal plants. It describes methods to obtain plants resistant to insects, diseases, herbicides, and plants with an increased production of compounds of medicinal and pharmaceutical importance. The plant species included are "Ajuga reptans," "Anthemis nobilis," "Astragalus" spp., "Atropa" "belladonna," "Catharanthus roseus," "Datura" spp., "Duboisia" species, "Fagopyrum" spp., "Glycyrrhiza" "uralensis," "Lobelia" spp., "Papaver" "somniferum," "Panax" "ginseng," "Peganum" "harmala," "Perezia" spp., "Pimpinella" "anisum," "Phyllanthus" "niruri," "Salvia" "miltiorrhiza," "Scoparia dulcis," "Scutellaria" "baicalesis," "Serratula" "tinctoria," "Solanum aculeatissimum," "Solanum " "commersonii," "Swainsona galegifolia," tobacco, and "Vinca minor."
This book is of special interest to advanced students, teachers, and researchers in the field of pharmacy, plant tissue culture, phytochemistry, molecular biology, biomedical engineering, and plant biotechnology in general.

This book contains the majority of the presentations of the Second International Symposium on the Biology of Root Formation and Development that was hcld in Jerusa lem, Israel, June 23---28, 1996. Following the First Symposium on the Biology of Adventi tious Root Formation, held in Dallas. USA, 1993, we perceived the need to include all kinds of roots, not only the shoot-borne ones. The endogenous signals that control root formation. and the subsequent growth and development processes, are very much alike, re gardless of the sites and sources of origin of the roots. Therefore, we included in the Sec ond Symposium contributions on both shoot-borne (i.e., adventitious) roots and root-borne (i.e., lateral) roots. Plant roots have remained an exciting and an intriguing field of sciencc. During thc years that followed the first symposium, an exceptional proliferation of interest in root biology has developed, associated with the intensive research activity in this field and the contemporary developments in the understanding of root function and development. New methods have been applied, and old ideas and interprctations werc rccxamined. Alto gether, it became necessary to update our viewpoints and to expand them.

This is an extended version of lectures that were held at the summer workshop Atmosphiirische Umweltforschung im Spannungsfeld zwischen Technik und Natur (At mospheric Environmental Research between Technology and Nature) at the Techni 16, 1996. We were very happy to have Paul J. Crutzen, cal University in Cottbus on July winner of the Nobel Prize for chemistry in 1995, presenting the key lecture on glo bally changing chemistry in the atmosphere. Over the last decades, atmospheric chem istry has been established step by step, not just as an applied discipline of chemistry, but also as a key discipline for our understanding of air pollution, biogeochemical cycling, and climactic processes as well. In fact, the new definition of meteorology as the science of physics and chemistry of the atmosphere expresses this development very well. The chemistry of the atmosphere is strongly influenced by anthropogenic emissions, even on a global scale. As a result of emissions and chemical reactions, the chemical composition of the atmosphere influences the ecosystems directly via depo sition of trace substances, and indirectly by changing the physical climate. Therefore, in this book we combined state-of-the-art lectures describing the physical and chemi cal status of the atmosphere and selected issues representing the interface between atmosphere, technology and nature. Oxidising capacity, heterogeneous processes and acidity still remain as key issues in atmospheric chemistry, even in regions where efficient air control measures have been adopted resulting in reduction of primary atmospheric pollutants."

The Dictionary contains the names of nearly 2500 plant species, in some cases including subspecies and varieties. Tropical crops from all parts of the world receive the same attention as those from the temperate zone. Common names are given not only in English, French, German, Portuguese and Spanish but also in many other languages, where such names are used in the technical literature. Agronomic plants' comprise not only the agricultural and horticultural crops but also pasture plants, green manure, soil covers, trees used in agroforestry, and major weeds. Also included are plants which are presently being discussed as new crops, with considerable economic value. The Dictionary will meet the needs not only of scientists in agriculture, botany and geography but also those of agricultural extensionists, merchants in agricultural products and professional translators.

The subject of fruit ripening is one of vital interest and importance to the massive international fruit growing and fruit trade industries. This book is the definitive handbook on the subject, bringing together a vast wealth of important information from an experienced team of international contributors.

Tropical climates, which occur between 23 Degrees30'N and S latitude (Jacob 1988), encompass a wide variety of plant communities (Hartshorn 1983, 1988), many of which are diverse in their woody floras. Within this geographic region, temperature and the amount and seasonality of rainfall define habitat types (UNESCO 1978). The F AO has estimated that there 1 are about 19 million km of potentially forested area in the global tropics, of which 58% were estimated to still be in closed forest in the mid-1970s (Sommers 1976; UNESCO 1978). Of this potentially forested region, 42% is categorized as dry forest lifezone, 33% is tropical moist forest, and 25% is wet or rain forest (Lugo 1988). The species diversity of these tropical habitats is very high. Raven (1976, in Mooney 1988) estimated that 65% of the 250,000 or more plant species of the earth are found in tropical regions. Of this floristic assemblage, a large fraction are woody species. In the well-collected tropical moist forest of Barro Colorado Island, Panama, 39. 7% (481 of 1212 species) of the native phanerogams are woody, arborescent species (Croat 1978). Another 21. 9% are woody vines and lianas. Southeast Asian Dipterocarp forests may contain 120-200 species of trees per hectare (Whitmore 1984), and recent surveys in upper Amazonia re corded from 89 to 283 woody species ~ 10 cm dbh per hectare (Gentry 1988). Tropical communities thus represent a global woody flora of significant scope.

Fantasies and dreams have their rightful place in science, and sometimes they turn into reality. Regeneration of hybrid plants through protoplast fusion is one such dream come true. In the early 1970s I shared the pioneering excitement in the field of protoplast technology at the Second International Congress of Plant Tissue Culture held in Strasbourg, France. Subsequently, I participated in three international conferences devoted to plant protoplasts, in Salamanca, Spain (1972), Versailles, France (1972), and Nottingham, England (1975). At Versailles Dr. P.S. Carlson presented his work on the successful regeneration of somatic hybrids between Nicotiana glauca and Nicotiana langsdorfii. The enthusi- asm shown by the participants was sufficient indication of the bright future of somatic hybridization. On my return from Versailles, I gathered my thoughts and prepared a concept paper on Potentials of Protoplast Culture Work in Agriculture which was published in Euphytica (Bajaj 1974). The studies on protoplast fusion and somatic hybridization then gained momentum and active work started in many laboratories. Very significant work was done by Melchers et al. (1978) who obtained a somatic hybrid between potato and tomato, calling it "Pomato".

Elms occur, both naturally and cultivated, throughout much of the temperate world. Because of their high tolerance to extreme growing conditions and their widespread distribution, elms have been widely planted in cities, towns and rural areas throughout North America and northern Europe. As such, their current demise due to several pandemics of Dutch elm disease has spurred a huge body of research on breeding for disease resistance, conservation and systematics. The Elms: Breeding, Conservation and Disease Management provides the current state of knowledge in these areas and is an important reference work for pathologists, breeders, taxonomists, and arborists.

r-------------{ Environment (Disease) Fig. 1. A schematic presentation of the interplay between the external environment, pathogen and animal, which influences resistance to infectious disease. Disturbance in equilibrium results in infection and disease skin and the mucous membranes of the respiratory tract. These tissues are in contact with the environment, and direct injury to them facilitate entry of pathogenic microorganisms through these important natural barriers. Sunburn and frostbite are examples of such adverse effects. Climatic factors such as heat and cold may also act as physiological stress factors which affect the specific and non-specific responses of the body to infection. 1.1.2 Pathogen Survival Climatic factors may affect dispersal, spread and survival of pathogenic micro organisms in the environment. This is also true for arthropod vectors such as mosquitos and ticks (Smith 1970; Ferguson and Branagan 1972). The density of the animal population is an important factor determining the concentration of patho gens in the environment. Population density can be influenced by weather condi tions, as animals respond to heat and cold by typical changes in behaviour. For example, in cold weather they tend to huddle together. This behaviour results in increased population density, which in turn involves an increased risk of the spread of airborne infections."

When I received an invitation to attend the International Symposium on Lethal Yellowing being organised by the Centro de Investigacion Cientifica de Yucatan (CICy), I was excited and a little nostalgic. During the 1970s, a series of similar symposia had been held under the auspices of the loosely-constituted "International Council on Lethal Yellowing" (ICL Y). These were the years when the MLO cause for L Y was first proposed, a vector was found, the disease was racing across mainland Florida, USA and it was suspected of having jumped to Cozumel. Analogous diseases were also reported to be spreading in Africa and elsewhere. The ICL Y meetings, held approximately every two years, proved to be an immensely valuable forum for all involved in the research and control of L Y. They attracted a very wide cross-section of scientists and practitioners working on L Y, on related diseases, and on palms in general. Many participants of those ICL Y meetings also attended this CICY Symposium. Unfortunately, during the 1980s, as countries learned to live with L Y, most of the national and international funding for L Y research dried up, and so did ICL Y. The present symposium is the only international meeting to have been devoted to L Y since the last meeting of rCLY in 1979. Its convening in Merida is timely.

The quality of human life has been maintained and enhanced for generations by the use of trees and their products. In recent years, ever rising human population growth has put tremendous pressure on trees and tree products; growing awareness of the potential of previously unexploited tree resources and environmental pollution have both accelerated development of new technologies for tree propagation, breeding and improvement. Biotechnology of trees may be the answer to solve the problems which cannot be solved by conventional breeding methods. The combination of biotechnology and conventional methods such as plant propagation and breeding may be a novel approach to improving and multiplying in large number the trees and woody plants. So far, plant tissue culture technology has largely been exploited in the propagation of ornamental plants, especially foliage house plants, by com mercial companies. Generally, tissue culture of woody plants has been recal citrant. However, limited success has been achieved in tissue culture of angiosperm and gymnosperm woody plants. A number of recent reports on somatic embryogenesis in woody plants such as Norway spruce (Picea abies), Loblolly pine (Pinus taeda), Sandalwood (Santalurn album), Citrus, Mango (Mangifera indica), etc., offer a ray of hope of: a) inexpensive clonal propa gation for large-scale production of plants or "emblings" or "somatic embryo plants," b) protoplast work, c) cryopreservation, d) genetic transformation, and e) artificial or manufactured seed production."