Trans. Br. my col. Soc. 84 (2), 375- 379 (1985)

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Printed in Great Britain

REVIEWS

The Applied Mycology of Fusarium. Edited byM. O. Moss & J. E. Smith (British MycologicalSociety Symposium 7, Cambridge University Press,1984). Pp. x +264. Price £32.5° or $64.50.

The genus Fusarium is one of the best known and moststudied groups of fungi . Its species are important aspathogens of plants and animals, as producers ofmetabolites, both toxic and useful, and more recently assources of microbial protein. They have also gainednotoriety since their toxic metabolites were found insamples associated with' yellow-rain' alleged to have beenused in warfare in south-east Asia . It was thereforeappropriate that the British Mycological Society shouldsponsor a symposium on the applied mycology ofFusarium in September 1982. Applied and fundamentalaspects of the genus were discussed and the major papersare now published in this volume.

The book contains 14 chapters covering taxonomy(C . Booth), ultrastructure and physiology (R. Marchant),genetics (J. H. Burnett), plant, insect and animal infection(D . Price, R. B. Drysdale, N . Claydon and J. F. Grove,P . K. C. Austwick), the occurrence, detection, synthesisand effects of metabolites toxic to animals (J. E. Smith,I. Mitchell & M. L. Chiu, J. Gilbert, M. O. Moss,C. J. Mirocha), useful metabolites (J. D. Bu'Lock), bio-mass production (C. Anderson & G. L . Solomons) andbiodeterioration 0. L. Thomas). Inevitably a book suchas this must be selective in the topics included andimportant aspects are omitted. For instance it is perhapssurprising that there is no mention of the controversiesthat have surrounded Fusarium taxonomy, while the roleof Fusarium in plant disease is limited to consideration ofthe significance of chlamydospores and phytotoxins andin bioterioration to pharmaceutical products. Publicationjust 3 years after 'Fusarium: Diseases, Biology andTaxonomy ' edited by P. E. Nel son , T . A. Toussoun andR. J. Cook (Penns ylvania State University Press, 1981)invites comparison of the two books . The new book is amuch slimmer volume and although prices ofthe two aresimilar in Britain, in the U .S .A. ' T he Applied Mycologyof Fusarium' is considerably more expensive. Emphasison diseases is much greater in the book by Nelson et al.and there is mu ch fuller consideration ofecology, geneticsand cytology, physiology and histopathology and taxon-omy than in 'The Applied Mycology ofFusarium ' . On theother hand, Moss and Smith have included chapters onultrastructure, biodeterioration, insect pathogenesis,useful metabolites of Fusarium and biomass productionthat are not referred to in the earlier book and also muchimproved discussion of rnycotoxins and mycotoxicosesassociated with Fusarium with reference to the new workon tibial dyschondrophasia in chickens and effects ofFusarium metabolites on hatchability of eggs . The twobooks can thus be considered complementary with onlya limited degree of overlap although where this doesoccur, the American book is usually more comprehensive.

'The Applied Mycology of Fusarium' is well produced,

with few misprints and has useful systematic and subjectindices. It brings together many diverse aspects ofFusarium to give a useful introduction with the variousbibliographies providing leads to more detailed informa-tion on each topic. It is thus likely to be of most use totho se making a first acquaintance with the genus.

J . LACEY

Mycorrhi zal Symbiosis. By J. L. Harley and S. E. Smith(Academ ic Press, 1983). Pp. 483, with 15 plates and 39text-figures. Price £35 .00 or $55.00 .

The appearance of a new book on mycorrhizas is mostappropriate, and will be welcomed, in response to thetremendous development of interest in the topic duringrecent years. Mycorrhizal Symbiosis clearly has its originsin the earlier texts produced by the senior author (TheBiology of Mycorrhiza , published in two editions, 1959and 1969), but it is doubtful whether one person couldnow cope with the assimilation of all the recent literature.The joint authorship of the present book is itself asuccessful symbiosis since it has retained the general' feel 'and character of the earlier work while at the same timechanging the format and content with the objective,concisely expressed in the Preface, ofgiving ' our personalappreciation of the subject and (reflect ing) our owninterests ' . This is seen most clearly in the five essays (seelater) which form the second part of the book and providea personal view of several specific, fundamental aspectsofmycorrhizas. The authors also express their concern toavoid the production of a stereotyped review and theysucceed, as a result, in making their material morereadable than it might otherwise have been.

The book starts with an Introduction which conciselydescribes the nature of symbiosis, highlights the problemof terminology and gives a classification of mycorrhizas.There then follow nineteen chapters, fourteen of which(Part 1) make up four sections dealing with each of themajor types of mycorrhiza and occupying the major partof the text. The five essays comprise Part 2, almost aseparate book, just over one quarter of the text.

The first section of Part 1 deals with vesiculararbuscular mycorrhizas (VAM), the commonest form offungus-root association. Separate chapters describe thesymbionts, development and anatomy, carbon metabolismand mineral nutrition. The whole is an orderly synthesisfrom a plethora of recently published work and it wouldbe difficult to achieve a better coverage. I would havepreferred to see separation of anatomical structure frominfection and modelling, perhaps as separate chapters, andalso a wider coverage of the information on fungi. Butthese are minor criticisms and are more than compensatedby the assessment of recent work on nutritional andmetabolic aspects of the relationship.

The second section, on ectomycorrhizas, opens with aconcise chapter on the symbionts and then deals withstructure in a comprehensive manner which brings nearlya hundred years of observation into perspective, and also

376 Reviewsdescribes the general pattern of infection and spread . Twochapters on growth physiology of, and pr oduction ofmetabol ites by the fungi reflect the culturability of thi sgroup and the interest the y have commanded frommycolog ist s. Then follows a chapter dealing with growthand carbon metabolism of the mycorrhizal plant and oneon' physiology' which covers nutrients other than carbon.Understandably perhaps, the authors make little referenceto the difficulties associated with the recognition andclassification of mycorrhizas and the associated problemsof synthesis in controlled conditions. A brief chapter onconiferous ectendomycorrhizas concludes what is by farthe large st section of the whole book .

The next section includes ericoid, arbutoid andmonotropoid mycorrhizas. Comparison with 25 years ago,when the senior author described the controversy oversuch forms, shows what dramatic progress has been madein both experimental work and structural understanding.Although occupying only one chapter, ericaceous mycor-rhizas are brought into perspective, with many interestingcomparisons between them and the two major typespreviously discussed.

To conclude Part 1 there is one chapter on orchidmycorrhizas in which present knowledge is comprehen-sively reviewed and the authors rightly emphasize theneed for more studies with adult orchid plants and ,particularly, the achlorophyllous members of the familywhich may be involved in complex triple symbioses innature.

Part z, the five chapters which take the form of essays,is a particularly attractive feature of th is book . It allowsthe authors to draw from several sources, i.e. the sorts ofmycorrhizas earlier described, information which is thensynthesized into broad concepts relating to the overallfundamental principles of the symbiosis. It-also allows theauthors more freedom to express their philosophicalthoughts and focus on future research needs. Forinstance, the first essay, on causal anatomy of ectomycor-rhizas, critically summarizes past work . The difficulties ofrelating in vitro experiments with high concentrations ofsugars and hormones to actual field conditions lead to theconclusion that more anatomical, developmental andanalytical studies are needed, and should be based on'ecologically probable conditions '.

The second essay discusses translocation in mycorrhizalfungi, against the background of knowledge of transloca-tion in general, and gives a comprehensive analysis ofpossible mechanisms, flow rates and comparisons withsaprotrophic fungi. It leads naturally to the next topic,that of transfer of metabolites. Here, there is less factualinformation to go on and hence more speculation;nevertheless the outcome is a credible assessment of ideas,interpretations and outstanding problems. The authorscannot be held responsible for the fact that mostinformation relates to ectomycorrhizas but many readersmay have liked to see more speculative comment on thesubstances transferred in other mycorrhizas.

The fourth essay grapples with problems of specificityand recognition, making some comparisons with othersymbiotic systems, and in the final chapter a considerationof ecological aspects rounds off the whole. In a fairl ygeneral style and relatively few pages, many applicationsof mycorrhizas in the broad ecological concept are

concisely expressed . Hopefully ecologists and rootphysiologi sts will take note!

There is a comprehensive list of over a thousandreferences , carefully selected to avoid tedious repetit ionfrom earl ier works, and a fairl y simple index in which thesub-sect ioning and cross referencing of the top ics couldbe better arranged. For example, of the seeminglyhundreds of sub-headings under 'vesicular-arbuscular',the term 'lysis ' cross-refers to ' degeneration ' , then' disint egration ' , and finally to many separate butunspecified page numbers. Again, ' ectomycorrhiza' withits sub-headings occupies nearly one quarter of the wholeindex and is not easy to unravel.

There are a number of minor typographical errors, e.g.Allen precedes Alexander in the list of references, andspelling faults, but a book of this nature would beremarkable if it were perfect. It is unfortunate that somemore serious faults gave rise in the first printing to errorsnot present in the proofs, which led to a considerable delayin the delivery of copies (and hence the late appearanceof this review).

The quality of some of the illustrations, e.g. Plates 9Aand 10, is less than one might expect in a book of thi snature and the make-up of many of the plates reflectspoorly on the technical expertise of a leading publisher.Also, one or two of the Figures could usefully have beenre-drawn. I find it curious that the pre-reader has notculled the occasional loose term such as 'blackberry-like'on p . 22 for the ' single, orderly layer (of) S clerocystischlamydospores ' - clearly illustrated in a plate, in thiscase - or the use of terms like ' as mentioned' without anycros s-reference to locations.

But these criticisms in no way detract from the truevalue of M y corrhizal Symbiosis. It provides a comprehen-sive panoramic overview of the subject and the authors areto be congratulated for the breadth of their vision as wellas for the incisive scru tiny which they apply to manycritical areas of knowledge and potential research. It is abook which should be on the shelves of all truernycorrhizasts and if the price is a deterrent it should beregarded as an investment, with a potential return formany years to come .

GEOFFREY HADLEY

The Nature and Practice of Biological Control of PlantPathogens. By R. J. Cook and K. F. Baker (AmericanPhytopathological Society, St Paul, Minnesota, 1983).Pp. 539· Price $43.00.

To a pathologist and a relatively recent newcomer tobiological control, this book should be compulsivereading. Indeed it is, in parts being both stimulating andinformative. However, it can also be frustrating and evenslightly annoying if one cannot relate to the style, thesome-what repetitious nature of the text (Gaeumannomycesgraminis var . tr itici has over 50 major citations), and theat times elementary maxims, exemplified by the ' prin-ciples ' in bold print which command obe yance . A numberof crop diseases which are amenable to biological controlare highlighted by being placed in boxes and scatteredalmost randomly through the book. The authors claimthat thi s is not a revision of their earlier work (B iologicalControl ofPlant Parhogens, 1974) and with more than 80 %of the references being newly cited it clearly is not. Indeed