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Suggestions for an International Herbarium of plant pathogenic fungi
[ 346 ]
SUGGESTIONS FOR AN INTERNATIONAL HERBARIUM OF PLANT PATHOGENIC FUNGI* By PAUL NEERGAARD The publication of mycological exsiccatae in the past has been almost exclusively a matter of private initiative. The great value of this tremendous collecting work performed during the past century should not be underrated, but it must be admitted that in most cases the material has been collected by chance and determined by mycologists who could not possibly be specialists in the numerous fungous groups with which they dealt. The many misidentified specimens do more to complicate than to simplify identification of new material, and a short cut to sure determination is badly needed, especially for plant pathologists. The publishing of an International Herbarium, based on contributions from selected specialists, with the nomenclature steadily kept up to date, would make it possible to establish a much needed co-operation between the mycological taxonomists and the plant pathologists, who often cannot spend much time on taxonomic studies. I propose the following principles to be taken into consideration for the realization of the suggested Herbarium. I.
COLLECTING
The purpose of the herbarium is to facilitate identification of plant pathogenic fungi: hence, saprophytic forms belonging to genera containing parasitic forms must be included. Examples of groups entitled to be included are: Alternaria, Ascochyta, Botrytis, Cercospora, Ciboria, Cladosporium, Colletotrichum, Coniothyrium, Cylindrocarpon, Cystopus, Cucurbitaria, Didyrnella, Diplocarpon, Entyloma, Erysiphaceae, Fusarium, Gloeosporium, Helminthosporium, Heterosporium, Marssonina, Mycogone, Mycosphaerella, Nectria, Ovularia, Peronospora, Pestalozzia, Phoma, Phyllosticta, Phytophthora, Plasmodiophora, Polyporus, Pythium, Ramularia, Rhizoctonia, Rhytisma, Sclerotinia, Septaria, Sphaceloma, Stagonospora, Stemphylium, Taphrinaceae, Uredinales, Ustilaginales, Venturia, Vermicularia, Verticillium. Whenever possible material of the same fungus (same collection) should be issued from (I) a natural substratum, (2) an artificial medium, as an isolate. All the material for a given specimen should be taken from one locality and one crop or substratum. Enough material should be collected to satisfy any request to be expected for a long period of time. If, for example, 500 labelled packets should be made to cover the demand for some years, an ample supply of reserve material should be kept for dividing and packeting later, if that should prove necessary. 2.
DETERMINATION
The determination should be based on the co-operation of specialists, invited to take care of the groups in which they have specialized. More than one specialist in a group can be invited, and it is even preferable that the material be determined by two specialists, who should be cited as determiners on the label. For a long time it would probably be impossible to find specialists for all the fungus groups that should be represented. But in any case it would be preferable to limit the issuance of items to the forms for which a well-documented determination could be given. Specialists of single species could be invited to contribute material of the species in question. In brief, the old herbaria rendered material incidentally found and more or less tentatively determined. For the suggested herbarium, the collecting work should follow a prearranged plan: the forms to be included should be well known to specialists and should -as far as possible-be chosen in advance and, at the beginning, be selected preferably from the economically or taxonomicalIy more important forms. • Though pleased to publish this contribution from an eminent Danish colleague, the Council of the Society wish to point out that they do not necessarily share his views.
International Herbarium of Plant Pathogenic Fungi
347
3. LABELLING The following data are proposed to be given on the label (see sample label below): (a) Name of the exsiccata (b) Issue number of the specimen (c) Name of the fungus, including author(s) and date of publication (d) Synonyms, including author's name(s) followed by date of publication (e) Substratum (host, artificial medium) (f) Date and locality of collection. For material obtained by culture: (aa) Date of isolation (bb) Substratum from which the fungus is isolated and the date and locality of the collection of that material (cc) Date of transferring the fungus to the medium used for the issue (dd) Date of drying the culture (g) Bibliography: (aa) Reference to original diagnosis (bb) Reference to the first use of accepted name (cc) Reference to diagnosis in Saccardo Sylloge Fungorum (dd) Monograph(s) (ee) Most important literature. If data on the specimen are published, this should be specially indicated (h) Name of determiner(s) (i) Remarks on possible deviations of the specimen from the normal form (the type) (j) In case of dispute on the nomenclature, references to be made to papers containing the determiner's arguments. Where there is complete disagreement between two selected authorities (as to type of the species, etc.) duplicate labels should be attached (k) Date of issuance of the label, and number of the edition, e.g. March 1952, znd edition HERBARIUM PHYTOPATHOLOGICUM NOMEN NESCIO No. 123 rst edition of label, issued Aug. 1952 Heterosporium iridis (Faut. & Roum.) Jacques 1941 Syn.: Scolecotrichum iridis Faut. & Roum. 1891. Heterosporium montenegrinum Bub. 1903. Scolecotrichum cladosporoideum Maire 1906. On malt extract agar, isolated 19 Feb, 1950 from Iris germanica (coIl. 2 September, 1949 in Branchport, New York, U.S.A.--material issued as Herb. Phytopath. N. N. No. 122), transferred last time 22 March, 1950, the culture dried 3 April, 1950. References: Original diagnosis: Roumeguere : Fung. Sel. Gal. Exs, No. 5689. 1891. New combination: Jacques, J. Emile: Studies in the genus Heterosporium-s-Contr. de l'Inst. Bot. de l'Univ. Montreal, No. 39: I-59· 1941. SACCARDO: Syll0!t.e Fungorum 10: 600. 1892. KLEBAHN, H.: Uber drei auf Iris gefundene Perithezien und die zugehorigen Konidienpilze.-Ber. Deut.Bot. Gesell. 42 (Generalversammlungs-Heft): 60-71. 1925. PERRAULT, C.: A common leaf spot of Iris in Quebec.-Quebec Soc. Prot. Plants Ann. Rep. 19: 87-103. 1927. RAMSBOTTOM, J. K.: Iris leaf-blotch disease (Heterosporium gracile Sacc.)-]. Roy. hort. Soc. (London) 40: 48 1-9 2. 1915. SIBILIA, C.: 'Saltazioni' in Heterosporium gracile.-Boll. Staz, Pat. Veg. Roma, N.S. 14: 447-474· 1934· . TISDALE, W. B.: Iris leaf spot caused by Didymellina iridis.-Phytopath. 10: 148-163. 1920. Det. N. N., Montreal, Canada, and X. X., London, England.
Transactions British Mycological Society New labels should be issued to provide for corrections of possible errors in identifications, to take care of new combinations, new synonyms, or to cite new important literature-in brief, to keep the herbarium up-to-date.
4. PUBLICATION OF NEW SYSTEMATIC ITEMS (NEW SPECIES ETC.) New species etc. can be accepted for publication in the herbarium when a sufficient amount of type material (on host or on artificial medium) is rendered and recognized by the appointed specialists taking care of the fungus group in question. Obviously the realization of a herbarium as outlined above would be a very large undertaking which undoubtedly would have to be built up gradually. The co-operation of mycological taxonomists must be based primarily on voluntary effort. The result might be, therefore, that some groups would be predominantly represented because of more diligent co-operation of some of the appointed specialists than of others. But with time that can be regulated. It would be the object of the enterprise to make the exsiccatae so valuable and well documented that all the main institutions of the world performing mycological and plant pathological investigations would be willing to subscribe for a complete set, thus facilitating identical determination of at least the most common and the most important plant pathogens.
(Accepted for publication 30 June 1947)
SUGGESTIONS FOR AN INTERNATIONAL HERBARIUM OF PLANT PATHOGENIC FUNGI* By PAUL NEERGAARD The publication of mycological exsiccatae in the past has been almost exclusively a matter of private initiative. The great value of this tremendous collecting work performed during the past century should not be underrated, but it must be admitted that in most cases the material has been collected by chance and determined by mycologists who could not possibly be specialists in the numerous fungous groups with which they dealt. The many misidentified specimens do more to complicate than to simplify identification of new material, and a short cut to sure determination is badly needed, especially for plant pathologists. The publishing of an International Herbarium, based on contributions from selected specialists, with the nomenclature steadily kept up to date, would make it possible to establish a much needed co-operation between the mycological taxonomists and the plant pathologists, who often cannot spend much time on taxonomic studies. I propose the following principles to be taken into consideration for the realization of the suggested Herbarium. I.
COLLECTING
The purpose of the herbarium is to facilitate identification of plant pathogenic fungi: hence, saprophytic forms belonging to genera containing parasitic forms must be included. Examples of groups entitled to be included are: Alternaria, Ascochyta, Botrytis, Cercospora, Ciboria, Cladosporium, Colletotrichum, Coniothyrium, Cylindrocarpon, Cystopus, Cucurbitaria, Didyrnella, Diplocarpon, Entyloma, Erysiphaceae, Fusarium, Gloeosporium, Helminthosporium, Heterosporium, Marssonina, Mycogone, Mycosphaerella, Nectria, Ovularia, Peronospora, Pestalozzia, Phoma, Phyllosticta, Phytophthora, Plasmodiophora, Polyporus, Pythium, Ramularia, Rhizoctonia, Rhytisma, Sclerotinia, Septaria, Sphaceloma, Stagonospora, Stemphylium, Taphrinaceae, Uredinales, Ustilaginales, Venturia, Vermicularia, Verticillium. Whenever possible material of the same fungus (same collection) should be issued from (I) a natural substratum, (2) an artificial medium, as an isolate. All the material for a given specimen should be taken from one locality and one crop or substratum. Enough material should be collected to satisfy any request to be expected for a long period of time. If, for example, 500 labelled packets should be made to cover the demand for some years, an ample supply of reserve material should be kept for dividing and packeting later, if that should prove necessary. 2.
DETERMINATION
The determination should be based on the co-operation of specialists, invited to take care of the groups in which they have specialized. More than one specialist in a group can be invited, and it is even preferable that the material be determined by two specialists, who should be cited as determiners on the label. For a long time it would probably be impossible to find specialists for all the fungus groups that should be represented. But in any case it would be preferable to limit the issuance of items to the forms for which a well-documented determination could be given. Specialists of single species could be invited to contribute material of the species in question. In brief, the old herbaria rendered material incidentally found and more or less tentatively determined. For the suggested herbarium, the collecting work should follow a prearranged plan: the forms to be included should be well known to specialists and should -as far as possible-be chosen in advance and, at the beginning, be selected preferably from the economically or taxonomicalIy more important forms. • Though pleased to publish this contribution from an eminent Danish colleague, the Council of the Society wish to point out that they do not necessarily share his views.
International Herbarium of Plant Pathogenic Fungi
347
3. LABELLING The following data are proposed to be given on the label (see sample label below): (a) Name of the exsiccata (b) Issue number of the specimen (c) Name of the fungus, including author(s) and date of publication (d) Synonyms, including author's name(s) followed by date of publication (e) Substratum (host, artificial medium) (f) Date and locality of collection. For material obtained by culture: (aa) Date of isolation (bb) Substratum from which the fungus is isolated and the date and locality of the collection of that material (cc) Date of transferring the fungus to the medium used for the issue (dd) Date of drying the culture (g) Bibliography: (aa) Reference to original diagnosis (bb) Reference to the first use of accepted name (cc) Reference to diagnosis in Saccardo Sylloge Fungorum (dd) Monograph(s) (ee) Most important literature. If data on the specimen are published, this should be specially indicated (h) Name of determiner(s) (i) Remarks on possible deviations of the specimen from the normal form (the type) (j) In case of dispute on the nomenclature, references to be made to papers containing the determiner's arguments. Where there is complete disagreement between two selected authorities (as to type of the species, etc.) duplicate labels should be attached (k) Date of issuance of the label, and number of the edition, e.g. March 1952, znd edition HERBARIUM PHYTOPATHOLOGICUM NOMEN NESCIO No. 123 rst edition of label, issued Aug. 1952 Heterosporium iridis (Faut. & Roum.) Jacques 1941 Syn.: Scolecotrichum iridis Faut. & Roum. 1891. Heterosporium montenegrinum Bub. 1903. Scolecotrichum cladosporoideum Maire 1906. On malt extract agar, isolated 19 Feb, 1950 from Iris germanica (coIl. 2 September, 1949 in Branchport, New York, U.S.A.--material issued as Herb. Phytopath. N. N. No. 122), transferred last time 22 March, 1950, the culture dried 3 April, 1950. References: Original diagnosis: Roumeguere : Fung. Sel. Gal. Exs, No. 5689. 1891. New combination: Jacques, J. Emile: Studies in the genus Heterosporium-s-Contr. de l'Inst. Bot. de l'Univ. Montreal, No. 39: I-59· 1941. SACCARDO: Syll0!t.e Fungorum 10: 600. 1892. KLEBAHN, H.: Uber drei auf Iris gefundene Perithezien und die zugehorigen Konidienpilze.-Ber. Deut.Bot. Gesell. 42 (Generalversammlungs-Heft): 60-71. 1925. PERRAULT, C.: A common leaf spot of Iris in Quebec.-Quebec Soc. Prot. Plants Ann. Rep. 19: 87-103. 1927. RAMSBOTTOM, J. K.: Iris leaf-blotch disease (Heterosporium gracile Sacc.)-]. Roy. hort. Soc. (London) 40: 48 1-9 2. 1915. SIBILIA, C.: 'Saltazioni' in Heterosporium gracile.-Boll. Staz, Pat. Veg. Roma, N.S. 14: 447-474· 1934· . TISDALE, W. B.: Iris leaf spot caused by Didymellina iridis.-Phytopath. 10: 148-163. 1920. Det. N. N., Montreal, Canada, and X. X., London, England.
Transactions British Mycological Society New labels should be issued to provide for corrections of possible errors in identifications, to take care of new combinations, new synonyms, or to cite new important literature-in brief, to keep the herbarium up-to-date.
4. PUBLICATION OF NEW SYSTEMATIC ITEMS (NEW SPECIES ETC.) New species etc. can be accepted for publication in the herbarium when a sufficient amount of type material (on host or on artificial medium) is rendered and recognized by the appointed specialists taking care of the fungus group in question. Obviously the realization of a herbarium as outlined above would be a very large undertaking which undoubtedly would have to be built up gradually. The co-operation of mycological taxonomists must be based primarily on voluntary effort. The result might be, therefore, that some groups would be predominantly represented because of more diligent co-operation of some of the appointed specialists than of others. But with time that can be regulated. It would be the object of the enterprise to make the exsiccatae so valuable and well documented that all the main institutions of the world performing mycological and plant pathological investigations would be willing to subscribe for a complete set, thus facilitating identical determination of at least the most common and the most important plant pathogens.
(Accepted for publication 30 June 1947)