Senescence and Aging in Plants reviews the state of knowledge in the processes involved in plant senescence and aging. The book begins by discussing the emergence of senescence as a concept; experimental analysis of senescence; and patterns of senescence. It then examines membrane deterioration during senescence; photosynthesis in relation to leaf senescence; senescence of detached plant organs; changing patterns of nucleic acid and protein synthesis during senescence; and degradative and associated assimilatory aspects of nitrogen removal. This is followed by chapters on aspects of ethylene that may impinge upon its role in promoting senescence of higher plants; the role of cytokinins in plant senescence; the promoters and retardants of senescence; and the role of calcium in plant senescence. The concept of whole plant senescence is discussed, which can be subdivided into patterns, correlative controls, cessation of vegetative growth, declining assimilatory processes, assimilate partitioning, and hormonal controls. The final chapters cover the deterioration of cellular membranes during the plant aging process and seed aging.

The book contains the proceedings of the Fifth International Wheat Conference at which leading international scientists reviewed current research issues and developments in wheat improvement. The debated topics cover breeding and genetics, genetic resources and importance of free germplasm exchange, breeding for biotic and abiotic stresses, physiology, agronomy and mineral nutrition, grain quality and biotechnology. A significant number of presentations were made by participants from the former USSR and Eastern and Central Europe, making this book also a prime reference for current wheat research and production status in these countries. This book provides an opportunity for wheat scientists interested in global wheat improvement issues to obtain an insight into the research that is currently being conducted worldwide and the prospects of further improvement to meet the increasing demands for this food commodity.

From prehistoric times man has had a pecial s relationship with seed plants - as a source of food, materials for tools, buildings, clothing and pharmaceuticals, and for ornamenting his surroundings for his own delight (probably in that chronological order which, incidentally, also gives some indication ofthe priorities oflife). Today man's most important staple foods are derived directly from seeds as they have been since neolithic times. (It is a sobering thought, as Harlan* has pointed out, that nothing significant has been added to his diet since then. ) From those times he must have learned to collect, conserve and cultivate seeds; and the accumulated experience has been handed down. This book then is part of an ancient tradition, for here we are still primarily concerned with these skills. Seeds are plant propagules comprised of embryos in which growth has been suspended, usually supplied with their own food reserves and protected by special covering layers. Typically they are relatively dry structures compared with other plant tissues and, in this condi tion) they are resistant to the ravages of time and their environment. But resistant is a relative tenn and seeds do deteriorate: the type, the extent and the rapidity of the deterioration, and the factors which control it are important to agronomists, horticulturalists, plant breeders, seedsmen, seed analysts, and those concerned with the conservation of genetic resources.

Proceedings of the 5th International Wheat Conference, 10-14 June 1996, Ankara, Turkey