rare as the subjects of this book and does not detract fromthis thoroughly researched and well written and illustratedwork.

To sum up the writing of Peter Marren I can do no betterthan his description of Jocelyn Brooke on p. 237. `He isparticularly good on the tricks of temperament andcircumstance that turn people into `botanophiles' '. If youmanage to read this book without experiencing a surge of`botanophilia' I think it is safe to say that the subject is notfor you! This book is tremendously valuable for professionalconservationists, ®eld botanists and anyone who likes a jollygood read about plants.

Philip Lusby# 2000 Annals of Botany Company

doi:10.1006/anbo.2000.1060

Obroucheva NV. 1999. Seed germination: a guide to the earlystages. 158 pp. Leiden: Backhuys Publishers. $40.00(softback).

This compact little book sets out to inform us of the eventsthat convert a seed from the dry, quiescent condition intothe germinated state. The author has spent many yearsstudying this transformation, prompted in part by herearlier investigations of root growth.

Her analysis of the sequence of changes set in train by theinitial hydration of the dry seed is expounded in fourchapters. The ®rst covers the di�erent patterns of growthoccurring in epigeal and hypogeal seedlings, and the timingof cell division and cell enlargement in relation to morpho-logical development. After a detailed critical discussion, shecomes ®rmly to the conclusion that cell elongation is theprimary growth process that determines the emergence ofthe axis from the seed, and that initiation of cell division isregulated independently. In the second chapter, the authorconsiders hydration of the seed, including the operation anddevelopment of all the components making up the seedwater potential, and then continues with an account of themetabolic events set in motion and driven by the increasinghydration, i.e. respiration, protein and nucleic acid syn-thesis. Mobilization of the reserves in the axis, minor interms of the whole seed but of major importance for theearly growth of the axis, also receives treatment. A pointthat is emphasized with clarity is that each metabolicprocess has its own water potential threshold so that theseed's hydration progressively triggers the onset of thedi�erent sequential processes.

Cell elongation is the key event by which successfulgermination is de®ned: how is this initiated in a seed thathas become more and more metabolically active as aconsequence of increasing hydration? Professor Obrou-cheva argues that preparedness for cell elongation comesfrom the accumulation of osmotically active solutes andcell-wall loosening. The former clearly results from mobil-ization of the axis reserves and the latter, it is held, is acid-induced wall softening. There was at least one surprise foryour reviewer in this chapterÐthe absence of any discus-

sion of the role played by the tissues enclosing the embryoin the hydrodynamics of axial growth. It is clear that insome cases the turgor (hydrostatic pressure) of the radiclebuilds up because of the constraining force exerted by theendosperm. Much has been learned in the past few years ofthe softening process that occurs in the part of theendosperm surrounding the radicle tip, and of the enzymesinvolved in dissolution of the cell walls of this resistanttissue. All of this deserves at least a mention, but better stillsome discussion.

Chapter 4 presents the overall picture of quiescent seedgermination which returns to some of the subjects coveredin previous chapters such as hydration, metabolic acti-vation and RNA and protein synthesis. But new topics arealso introduced, for example the e�ects of temperature andoxygen in germination and the roles of hormones. Here,too, are some more surprises, for example the assertion that`no signi®cant e�ects of phytohormones, gibberellins inparticular, on early germination . . . have been detected'(p. 107) and `phytohormonal regulation of germinationcommences only after visible germination' (p. 119). Recentwork on GA and ABA mutants would certainly suggestotherwise, as did even earlier physiological research withinhibitors of GA biosynthesis. Some eyebrows might alsobe raised at the rather cursory treatment given to thehydrotime concept, which is being applied increasingly instudies of germination.

The pedant will be disturbed by the uncertainty whichturns up frequently as to what the author precisely meansby the term germination. Most seed biologists now takegermination, in the strict sense, to be those events precedingand leading to axial (generally radicle) emergence. Obrou-cheva clearly subscribes partly to this view, since most ofthe discussion in this book is concerned with pre-emergenceprocesses. But then the reader wonders what to make ofstatements exempli®ed by `changes in water relations priorto seed germination will be considered ®rst' (p. 37).

Leaving aside the criticisms, I recognize that this booko�ers a useful review of the processes occurring during seedgermination, in some respects with considerable detail,which will complement other writings. The author hascovered a wide range of literature, about 10% of which isRussian and she has performed a service in bringing it toour attention.

Michael Black# 2000 Annals of Botany Company

doi:10.1006/anbo.2000.1180

Shimamoto K. 1999. Molecular biology of rice. 304 pp.Tokyo: Springer-Verlag. £72 (hardback).

Rice is a vital food crop for the entire world population. It isestimated that grain production in rice must be increased by60% of the present value to meet demand in 2020 AD. Theproductivity of this crop has strong links to the economies ofseveral Asian countries. It is hardly surprising to ®nd that agreat deal of impetus has been given to research concerningthe molecular biology, genomics and biotechnology of the

206 Book Reviews

rice crop in recent years. Rice research has reached suchheights that, like Arabidopsis and tobacco, it is nowconsidered to be a model system. Among the monocots,rice is the best-studied plant material. A book on themolecular biology of rice is expected to be read by a largeaudience. It is heartening to see that this book has beenwritten by scientists who have made pioneering contribu-tions to rice research.

The book is divided into four parts: Part 1 pertains togenome analysis and gene isolation; Part 2 takes up issuesrelated to developmental biology; Part 3 is on regulation ofgene expression; and Part 4 contains information ontransformation and rice improvement. Of late, genomicsresearch has come to the centrestage of plant molecularbiology. Rice has the smallest genome (430 Mb) of thecereal crops (maize, wheat and barley have a genome sizeapprox. 6, 10 and 38 times larger than that of rice). Thecurrent status and future prospects for genome analysis inrice are discussed in the opening chapter of this book. Arecent trend in rice research is to improve local varieties byaugmenting traditional breeding e�orts with molecularmarkers. The details of molecular marker systems formapping loci governing economic traits in rice are provided.Pertaining to the functional genomics of rice, some use ofmaize transposon Ac/Ds and retrotransposons of rice isdescribed. The discussion on basic studies of rice develop-ment include identi®cation and characterization of themorphogenetic mutants, ¯ower development and homeo-box genes. An account of the phytohormone abscisic acid,which plays a key role in mediating responses of plants toenvironmental stresses such as salinity, drought and lowtemperature is taken up in a separate chapter. Chapter 9 israther over-specialized, detailing recent advances in a-amylase gene regulation in rice. The structure of variousrice seed storage proteins and organization and expressionof seed storage genes is well-presented. There is a great dealof research on biotechnological aspects related to pro-duction of pest- and pathogen-resistant rice. In this context,an account of the structure and functions of major bacterialblight and blast resistance genes is a welcome inclusion. Amajor breakthrough was made in the early 1990s when itwas shown that A. tumefaciens can be exploited for genetictransformation of rice cells. A complete chapter is devotedto take stock of the key factors involved in A. tumefaciens-mediated transformation of rice. One of the success storiesof plant biotechnology research is the production of virus-resistant transgenic plants. The molecular biology of rice-infecting viruses and the prospects of raising transgenicvirus-resistant plants are nicely presented. The ®nal chapterof this book highlights some of the current achievements ingenetic transformation of rice for di�erent traits.

This book contains a great deal of information onmolecular biology of the world's most-important foodcrop, and thus will be a bible to all workers in the ®eld ofrice molecular biology. Recent trends show that genomes ofmajor cereals share a high degree of synteny with the ricegenome. Therefore, this book will also be useful to thosewho are working on the molecular biology of crops likewheat, maize and sorghum. However, it must be realizedthat any such book will become out-dated in two to three

years. It is, thus, important that the editor of this bookbrings out an up-dated version as and when the need arises.Though this book is well presented, I take the liberty ofasking for more from the revised version. There is noexclusive account on the molecular biology and geneticengineering of rice for abiotic stress tolerance. Riceeconomists are of the view that abiotic stresses a�ect ricemore than biotic stresses. There is also no account of themolecular studies on genetic diversity of rice. This book hasa slant towards basic molecular biology. It will be appreci-ated if future editions of this book take up biotechnologicalissues pertaining to hybrid rice production, analysis ofQTLs for various agronomic traits, development of newvector systems, gene silencing and ®eld-trials of transgenicrice. Today rice research occupies a special place thanks tosupport from the Rockefeller Foundation (USA) and fromthe national governments of various countries particularlyJapan, China, India, Thailand, Korea and Philippines. Thisbook is a great service to the international rice community.

Anil Grover# 2000 Annals of Botany Company

doi:10.1006/anbo.2000.1185

Walker D. 1999. A leaf in time. `Making sense of science'.Children's Books. London: Portland Press, £6.99(soft back).

Rarely does Annals of Botany receive a book apparentlyon photosynthesis, aimed at children and written by aresearcher of such distinction. To encourage children toread about science and to learn at an early age about thefascination of the subject is important. Hence the review.However, how to review? The method chosen was a `strawpoll', by asking colleagues who have children of about theage thought to be the target for this book (no age group issuggested on the cover but 10±12 years seems appropriate).The comments were illuminating.

The book is 29 pages of text, heavily illustrated in brightcolours with a lively and pleasing appearance. It covers avery wide spectrum, starting with the concept of a `veryyoung' world without plants or animals, but with bacteria(spelled out as `bac-tear-ia' to help with pronunciation, atechnique used throughout the text) as the only living things.They are depicted (p. 3) as rather unclear circles in chains,but with speech balloons (`Bubble! Bubble!!' and `One day Icould be famous!') beneath a very stylized depiction of avolcanic crust. On p. 4, cyanobacteria, the onset of oxygenproduction, and the increase in atmospheric oxygen areintroduced together with a time scale of `one thousandmillion years'. The importance of oxygen for the planet tobreathe is mentioned. In the following pages there is a rapidjump to green plants, and their role in food production isintroduced using simpli®ed concepts of food chains. This isthen expanded into ecological concepts, illustrated bydi�erent ecosystems. Needless to say dinosaurs feature inthe development. Use of carbon dioxide by plants to makefood and the importance of carbon dioxide concentration isgiven prominence, including mention of units (`this gas is

Book Reviews 207