Photoperiodism is the response to the length of the day that enables living organisms to adapt to seasonal changes in their environment as well as latitudinal variation. As such, it is one of the most significant andcomplex aspects of the interaction between plants and their environment and is a major factor controlling their growth and development. As the new and powerful technologies of molecular genetics are brought to bear on photoperiodism, it becomes particularly important to place new work in the context of the considerable amount of physiological information which already exists on the subject. This innovative book will be of interest to a wide range of plant scientists, from those interested in fundamental plant physiology and molecular biology to agronomists and crop physiologists. Provides a self-sufficient account of all the important subjects and key literature references for photoperiodism Includes research of the last twenty years since the publication of the First Edition Includes details of molecular genetic techniques brought to bear on photoperiodism

Life evolves in a cyclic environment, and to be successful, organisms must adapt not only to their spatial habitat, but also to their temporal habitat. How do plants and animals determine the time of year so they can anticipate seasonal changes in their habitats? In most cases, day length, or photoperiod, acts as the principal external cue for determining seasonal activity. For organisms not living at the bottom of the ocean or deep in a cave, day follows night, and the length of the day changes predictably throughout the year. These changes in photoperiod provide the most accurate signal for predicting upcoming seasonal conditions. Measuring day length allows plants and animals to anticipate and adapt to seasonal changes in their environments in order to optimally time key developmental events including seasonal growth and flowering of plants, annual bouts of reproduction, dormancy and migration in insects, and the collapse and regrowth of the reproductive system that drives breeding seasons in mammals and birds. Although research on photoperiodic time measurement originally integrated work on plants and animals, recent work has focused more narrowly and separately on plants, invertebrates, or vertebrates. As the fields have become more specialized there has been less interaction across the broader field of photoperiodism. As a result, researchers in each area often needlessly repeat both theoretical and experimental work. For example, understanding that there are genetically distinct morphs among species that, depending on latitude, respond to different critical photoperiods was discovered separately in plants, invertebrates, and vertebrates over the course of 20 years. However, over the past decade, intense work on daily and seasonal rhythms in fruit flies, mustard plants, and hamsters and mice, has led to remarkable progress in understanding the phenomenology, as well as the molecular and genetic mechanisms underlying circadian rhythms and clocks. This book was developed to further this type of cooperation among scientists from all related disciplines. It brings together leading researchers working on photoperiodic timing of seasonal adaptations in plants, invertebrates, and vertebrates. Each of its three sections begins with an introduction by the section editor, and at the end of the book, the section editors present a synthesis of common themes in photoperiodism, as well as discuss similarities and differences in approaches to the study of photoperiodism, and future directions for research on photoperiodic time measurement.

(Chapters 11 to 14) summarise important features of the biological clock at the level of whole animal covering all vertebrate classes (fish to mammal). Chapters 15 and 16 are on long term (seasonal) rhythms in plants and higher vertebrates. Short term rhythms (ultradian rhythms), the significance of having a clock system in animals living in extreme (arctic) environments, and the diversity of circadian responses to melatonin, the key endocrine element involved in regulation of biological rhythms, have been discussed in Chapters 17 to 19. Finally, a chapter on sensitivity to light of the photoperiodic clock is added which, using vertebrate examples, illustrates the importance of wavelength and intensity of light on circadian and non-circadian functions. A well-known expert writes each chapter. When presenting information, the text provides consistent thematic coverage and feeling for the methods of investigation. Reference citation within the body of the text adequately reflects the literature as subject is developed. A chapter begins with an abstract that enables a reader to know at the first glance the important points covered in that chapter. The chapter concludes with a full citation of references included in the text, which could be useful for further reading. The book ends with a comprehensive subject index that may be useful for quick searches.

Insect Photoperiodism reviews the many aspects of photoperiodism, particularly in insects, emphasizing the concepts that serve to place the subject in a meaningful relationship to the whole of modern biology. Photoperiodism is the study of the adaptive mechanisms by which living systems exploit this source of temporal information. Organized into 12 chapters, this book begins by discussing the relationships between an endogenous behavioral rhythm and the exogenous photoperiod. Aside from behavioral activities, it also shows that some observable developmental events tend to occur at species-typical times of the day and to be photoperiodically regulated. Notably, photoperiod may exert either or both of two regulatory effects on insect development: growth rate effects or polymorphism. Furthermore, the characteristics of some of the principal physiological rhythms that have been studied; role of photoperiod in the control of diapauses; and the circadian functions and theoretical nature of biological clock are explored in this book.

The Novartis Foundation Series is a popular collection of the proceedings from Novartis Foundation Symposia, in which groups of leading scientists from a range of topics across biology, chemistry and medicine assembled to present papers and discuss results. The Novartis Foundation, originally known as the Ciba Foundation, is well known to scientists and clinicians around the world.

The Novartis Foundation Series is a popular collection of the proceedings from Novartis Foundation Symposia, in which groups of leading scientists from a range of topics across biology, chemistry and medicine assembled to present papers and discuss results. The Novartis Foundation, originally known as the Ciba Foundation, is well known to scientists and clinicians around the world.

Biological Rhythms and Photoperiodism in Plants brings together disparate subject areas into one accessible text of interest to all plant biologists. In this comprehensive volume, leading international researchers review our current understanding of circadian rhythms from a broad perspective. The book begins with a description of well known rhythmic processes such as gene expression, stomatal guard cell opening, and the movement of petals and leaves. Photoperiodic responses such as dormancy, bulbing, tuberization and flowering are then discussed in terms of their rhythmic behaviour. The latest data from current studies with mutant and transgenic plants is also included.