Completing the primary genomic sequence of Arabidopsis thaliana was a major milestone, being the first plant genome and well established as the premiere model species in plant biology. Since working drafts of rice (Oryza sativa L.) genome became available (Yu et al. 2002), it has become the s- ond-best model organism in plants representing monocotyledons. Understanding how the genome sequence comprehensively encodes de- lopmental programs and environmental responses is the next major ch- lenge for all plant genome projects. This requires functional characterization of genes, including identification of regulatory sequences. Several functional genomics approaches were initiated to decode the linear sequence of the model plant Arabidopsis thaliana, including full-length cDNA collections, microarrays, natural variation, knockout collections, and comparative sequence analysis (Borevitz and Ecker 2004). Genomics provides the ess- tial tools to speed up the research work of the traditional molecular gene- cist, and is now a scientific discipline in its own right (Borevitz and Ecker 2004).

With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences. The present volume includes reviews on genetics, cell biology, physiology, comparative morphology, systematics, ecology, and vegetation science.

With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences.
The present volume includes reviews on genetics, cell biology, physiology, comparative morphology, systematics, ecology, and vegetation science.

With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences.
The present volume includes reviews on genetics, cell biology, physiology, comparative morphology, systematics, ecology, and vegetation science.

With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences.
The present volume includes reviews on genetics, cell biology, physiology, comparative morphology, ecology and vegetation science.

The significance of genetics in biology today stems to a considerable extent from the knowledge which has been obtained through the use of fungi as experimental objects. As a result of their short generation time, their ease of culture under laboratory conditions, and the possibil ity of identifying the four products of meiosis through tetrad analysis, the fungi have proven themselves in many ways superior to the classic genetic experimental material such as Drosophila and maize. Because they permit investigation of genetic fine structure as well as biochemical analysis of the function of the genetic material, the fungi can be used, just as the bacteria and bacteriophages, for molecular biological research. Further, the fungi, because of their simple organi zation, are suitable for investigation of the genetic and physiological bases of morphogenesis and of extrachromosomal inheritance. This monograph is an attempt to summarize and interpret the results of genetic research on fungi. The reader should be reminded that review and interpretation of original research are inevitably influenced by the authors' own opinions. An understanding of the basic principles of genetics is assumed."

With one new volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of botany. The present volume in- cludes reviews on structural botany, taxonomy, geobotany, plant physiology, genetics, and floral ecology.

The 50th volume of Progress in Botany appears in new guise. In cooperation with Springer-Verlag we have changed from the less attractive typewriter composition to the direct reproduction of a manuscript which was writ ten by means of a text editing system and produced by a laser printer. We, the editors, should like to take the appearance of Volume 50 as the occasion for a few short remarks. Our younger readers are perhaps not aware that our Book Series was founded in 1931 by Fritz von Wettstein, based on the following thoughts and considerations, aptly formulated by him in the Preface to the first volume. "One of the greatest dangers threatening progress in the science of botany is the absolutely unbelievable growth in volume of the literature. The quality of journals, books and individual works that are daily sent to us makes it impossible for anyone person to maintain a general view of the progress made in botany in all the specialized fields, let alone to find time for results from associated su bjects. For varying reasons, every botanist must find this state of matters insupportable. Let us endeavor, in the general interest, to retain a wide background of knowledge, and not become limited specialists. The vitally necessary connections between the specialized fields can only flourish, or even exist, if the general view of botany as a whole can be maintained."

With one new volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of botany. The present volume includes reviews on plant physiology, genetics, taxonomy and geobotany.

With one new volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of botany.
The present volume includes reviews on structural botany, plant taxonomy, physiology, genetics and geobotany.

Der Senior unserer Herausgebergemeinschaft HEINZ ELLENBERG hat sich leider aus der Redaktion zuruckgezogen. Nach dem Tode von ERNST GXUMANN hatte er 1963 (ab Band 26) zusammen mit ERWIN BUNNING die Herausgeberschaft der "Fortschritte der Botanik" ubernommen. Seiner Aufgeschlossenheit und auch seiner Initiative ist die dann spater erfolgte Erweiterung des Herausgebergremiums und die damit verbundene inhaltliche Umgestaltung zu verdanken. In seiner nunmehr fast zwanzigjahrigen Betreuung des Abschnittes "Geobotanik" hat er dazu beigetragen, daB dieses Teilgebiet zu einer wesentlichen Saule unserer Reihe geworden ist. Herausgeber und Verlag mochten ihm fur seine Redaktionsarbeit danken und hoffen, daB Herr ELLENBERG ihnen auch weiterhin in alter Freund- schaft verbunden bleibt. An seiner Stelle . hat von diesem Band ab Herr MICHAEL RUNGE die Schriftleitung des Kapitels Geobotanik ubernommen. Die Herausgeber Contents A. MORPHOLOGY I. Cytology a) General and Molecular Cytology. By ANTHONY W. ROBARDS *** 1. Root Hairs ******************************************* 1 a) Development and Structure of Root Hairs *********** 1 b) Microbial and Other Associations with Root Hairs ** 3 2. Cytoplasmic Streaming ******************************** 6 a) General Experimental Effects on Cytoplasmic Streaming ***************************************** 7 b) Effects of Cytochalasin B on Cytoplasmic Streaming ***************************************** 8 c) Effects of Light and of Growth Regulators on Cytoplasmic Streaming ***************************** 9 d) The Role of Calcium in Cytoplasmic Streaming ****** 10 e) General Observations on Cytoplasmic Streaming ***** 11 3. Calmodulin ******************************************* 1 2 References ********************************************** 14 b) Special Cytology: Cytology and Morphogenesis of Higher Plant Cells - Phloem. By H. -D.

With one new volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of botany. The present volume includes reviews on structural botany, plant physiology, genetics, taxonomy, and geobotany.

This seris keeps scientists and advanced students specialized on a particular subject informed of the latest developments and results in all different areas of botany. The present volume includes reviews on structuralbotany, physiology, genetics, taxonomy, geobotanic, as well as a contribution treating seed dispersal.