Publication No. 30. Florida Agricultural Experiment Station Journal Series No The Fungal Flora of Waterhyacinth in Florida

Transcription

1 Publication No. 30 Florida Agricultural Experiment Station Journal Series No The Fungal Flora of Waterhyacinth in Florida By K.E. Conway, T.E. Freeman and R. Charudattan Plant Pathology Department, University of Florida

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3 Publicatiol1 No. 30 Florida A~ricllltural FX{Jerimcl/(,,)'(atiol1 Journal Series No The FIII/~al Flora of Jl'atcrhyacil1(11 ;11 Florida ljy K.E. Co 11 way. T.E. rrl't'l11al1 ami R. C!wrudalla" Plant PallwloKY f)/'par(/i/('f/i. UlliJ'ersily of Florida

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5 ABSTRACT THE FUNGAL FlOl1.A OF \-:.ATER.-'-fYACINTH IN FLORIDA, PART I.?C.E. Gonway, T.E.Freem:l.ll and. R. CharudattAn. Plant Pathology Department University of Florida, Gainesville, Research,las initiated to survey, isolate, identify, test, and catalogue all fungi associated, dth waterhyacinths. The ultirna:te goal of this project is to find organisms that can be used as biological controls to limit the growth rate or destroy the Haterhyacinth. An understanding of the role played by fungi in the decline and death of waterhyacinthhas been aided by studying both saprophytes andparsites. This report includes 30 species of fungi. The location, date of colj.ection, pathogenicity, and references for each isolate is provided. A more effective biocontrol should be possible by knowing vlhat environmental factors favor the presence of fungal pathogens on the. waterhyacinth...

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7 THE FUNGAL FLORA OF WATERHYACINTH IN FLORIDA By K.E. Conway T.E. Freeman and R. Charudattan PUBLICATION NO. 30 FLORIDA WATER RESOURCES RESEARCH CENTER and FLORIDA AGRICULTURAL EXPERIMENT STATION JOURNAL SERIES NO. 5519, September, 1974 The work upon which this report is based was supported in part by funds provided by the United States Department of the I nterior, Office of Water Resources Research as Authorized under the Water Resources Research Act of 1964.

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9 Part I K.E. Conway, T.E. Freeman, R. Charudattan Plant Pathology Dept., Univ. of Florida, Gainesville, Aquatic weeds in many lakes and streams in Florida have become the concern of scientists and sportsmen. Although aquatic pl;lnts perform a function, an overabundance can rapidly lead to a decrease in boating, fishing and environmental quality. Therefore, there is a need to limit the growth and spread of certain aquatic weeds. Currently, the number one problem is the waterhyacinth, estimated to infest thousand acres of water in the state of Florida. I n November of 1973, a project was initiated to survey, isolate, identify, test, and catalogue all fungi associated with waterhyacinths. The objective of this research was to find fungal organisms that could be used as biological controls to limit the growth rate or destroy the waterhyacinth. It was felt that a broad ranged approach looki ng at both parasites and saprophytes would significantly augment our understanding of the role played by fungi in the decline and death of the waterhyacinth. This approach would also aid our understanding of the natural succession of fungal organisms on the waterhyacinth. More effective biocontrol should be possible by knowing what environmental factors favor the presence of fungal pathogens. It is important that a catalogue of organisms be presented to form the foundations for further research. This report includes 30 species of fungi that have been found on waterhyacinth since the inception of this project. Each species is briefly described and information concerning its effect on waterhyacinth is presented. The organisms listed in this report represent two subdivisions of the Eumycota, the Ascomycotina and the Deuteromycotina. I. ASCOM YCOTI NA-A. Class Pyrenomycetes 1. MELANOSPORA ZAIAE Corda (Fig. 1) The fungus was isolated from the leaves of waterhyacinth. The perithecia (230J.L diam.) are superficial with a slender neck J.L long. The asci (44-70 x 2211) are long stal ked and evanescent. The ascospores (20-22 x J.L) are unicellular, smooth, and dark brown in color. Pathogenicity-Not confirmed Location-Lake Alice, University of Florida campus. Date-March Ref.-Dennis, 1968; Doguet, B. Class Loculoascomycetes 2. LEPTOSPHAERULINA sp. (Fig. 2) This organism was isolated from necrotic spots at the tips of the leaves. Ascostroma (150 J.L diam.) are erumpent and the asci measure x J.L. The asci are bitun icate, possessing two distinct wall layers. Ascospores (33 x 11 11) are hyaline, and muriform. Pathogenicity-Not confirmed Location-Lake Alice, University of Florida campus. Date-December Ref.-Von Arx, DIDYMELLA EXIGUA (Niessl.) Sacco (Fig. 3) This fungus was isolated from dying leaves of waterhyacinth. Ascostroma ( ) are singly im-. mersed in the leaf beneath the stoma. Asci measure x and the ascospores (12-15 x 5-6 J.L ) are two-celled and hyaline. Imperfect state-ascochyta Pathogenicity-Not confirmed-both Didyme//a exigua and Ascochyta imp. state Location-Rodman Reservoir; Lake Alice, University of Florida campus Date-December-January Ref. -Corbaz, MYCOSPHAERELLA TASS/ANA (de Not.) Johanson (Fig. 4) This organism was isolated from declining waterhyacinth leaves. This genus is morphologically similar to Didyme//a. Mycosphaere//a differs by: possessing a smaller ascocarp, having spores with a greater length-width ratio (with the bottom cell longer than the apical cell), lacking paraphyses, and lacking an Ascochyta imperfect stage in culture. The ascocarp measures J.L, the asci, x 9-10 J.L, and the ascospores, x 5-6/1. Pathogenicity-slight Location-Lake Alice, Rodman Reservoir. Date-April Ref.-Von Arx, II. DEUTEUROMYCOTINA-A. Coe/omycetes 5. PHOMA spp. (Fig. 5) Several species of p,homa have been isolated from waterhyacinth a'nd possess varying pathogenicity to waterhyacinth. Until further elaboration is possible a broad interpretation of the genus will be used to include species of Phy//osticta and Peyronellaea as well as small spored species similar to Asteromella. Pycnidia measure diam., and are immersed to superficial. Conidia measure 5-6 x 2-3 J.L. Pathogenicity-varies with species, from moderate to none. Location-Rodman Reservoir, Lake Alice, Labelle, Fla. Date-present throughout survey Ref.-Von Arx, BOTRYODIPLOIDEA sp. (Fig. 6) The genus Botryodip/oidea is often confused with the genus of Macrophoma. The conidia are at first hyaline, one-celled and thick walled, like Macrophoma. As they mature in the pycnidium they become brown, two-celled and the conidium wall may be slightly striated in color. The conidia measure x Botryodip/oidea was found erumpent on floral tubes of waterhyacinth. Pathogenicity-slight. Locati on-rod man Reservoi r Date-March Ref.-Von Arx, 1970., B. Hyphomycetes 7. CEPHALOTR/CHUM sp. (Fig. 7) 3

10 This fungus has been found on dead waterhyacinth leaves. The conidiophores are united into a synnema. The synnemata are light brown, capitate, with the stipe composed of parallel hyphae. The tips of the conidiophores are annellidic, conidia are one-celled, catenulate and are held together in a dry head. Conidia measure 8-10 x 4-5 }.1.. Synnemata are jj. in length. Cephalotrichum link is the genus selected by Hughes (1958) to replace the genus Doratomyces Corda. Pathogenicity-Not confirmed Location-Lake Alice Date-February Ref.-Morris, 1963; Morton and Smith, MYCOLEPTODISCU5 TERRE5TRI5 (Gerdemann) Ostrazeski (Fig. 8) This unique organism was isolated by Dr. R. Charudattan from waterhyacinths at Manatee Springs, Florida. Conidia are formed on a dark sporodochium and their development is enhanced by placing cultures in near-uv light. The sporodochium is flat and one-celled thick }1 diam. The individual conidiogenous cells are phialidic. The conidia are allantoid, two-celled, hyaline, x 5-7 /1, with seta at each end 8-18 fl long. Conidia are held in a mucilagenous mass. Pathogenicity-slight to none, producing a small zonate leaf spot. Location-Manatee Springs, Fla, Date-january-February Ref.-Sutton, 1973, 9, MYROTHECIUM ClNTUM (Corda) Sacco (Fig. 9) This fungus was isolated from waterhyacinth leaves. The fungus produces sporodochium and the conidia are held in a mucilagenous mass, The conidia are dark brown and may appear green in mass. Conidia measure x and are spirally striated, Pathogenicity-f']ot confirmed Location-Lake Alice Date-March Ref-M.B. Ellis, EPICOCCUM PURPURASCEN5 Ehrenb, ex Schlecht (Fig, 10) Epicoccum purpurascens is found abundantly on declining and dead waterhyacinths. It is a common saprophyte. Epicoccum produces sporodochium, The conidia are large, fl diam" dark brown and muriform. Pathogenicity-Not confirmed location-ubiquitous Date-throughout survey Ref-M.B, Ellis, , ALTERNARIA spp. (Fig, 11) Most Alternaria species are saprophytic on waterhyacinth. Conidia are dark brown, muriform, measure 8-10 x , and possess a beak as large as 20 fllong. Pathogenicity-Not confirmed Location-Ubiquitous Date-throughout survey Ref-Von Arx, 1970, 12, ASPERGILLUS A. A. flavus Link (Fig. 12) R A. niger Van Tiegh (Fig. 13) Species of Aspergillus are commonly isolated from declining and dead waterhyacinths, The most common species encountered is A. niger, The presence of A, ffavus in waterhyacinth should add a note of caution to those utilizing waterhyacinths as feed supplements, due to the possibility of aflatoxin production during feed preparation, Pathogenicity-none Location-Lake Alice, Rodman Reservoir Date-January-February Ref.-Raper & Fennell, ACREMONIUM ZONA TUM (Sawada) Gams, (CEPHALOSPORIUM ZONA TUM) (Fig, 14) This organism has been found in Florida, Louisiana, Panama, Puerto Rico, India and EI Salvador. It produces a zonate leaf spot. The conidiophores of this isolate are highly branched and phialidic. The conidia are 4-5 x 3 /1. This fungus is currently being field tested by Dr. TE, Freeman and appears to be useful as a means of reducing the productivity of the waterhyacinth. Cultures have been deposited (CBS 211,74) with the Centraalbureau Voor Schimmelcultures, Baarn, Netherlands. Pathogenicity-good to excellent. Produces a zonate leaf spot. location-lake Alice, Newnam Lake, Fort Lauderdale Date-October-December Ref.-Gams, 1971; Rintz, BIPOLARIS spp, (Fig, 15) Several species of the Bipolaris group have been isolated from waterhyacinth, Dr. R. Charudattan isolated the first species that is highly virulent on waterhyacinth from the Dominican His greenhouse tests show this isolate, designated /-felminthosporium stenospilum (Bipolaris stenospila), to be an aggressive pathogen of waterhyacinth. Other species of Bipo/aris, B. cynodontis (Marig,) Shoemaker have recently been discovered from the La Belle, Florida area and Lake Alice, Greenhouse tests are currently being undertaken on these species, Pathgoenicity-good (B. stenospila) Other species-slight to none. Location-La Belle, Fla., Lake Alice Date-May Ref.-M,B. Ellis, 1971; luttrell, CERCOSPORA sp. (Fig. 16) Two. species of Cercospora have been found and isolated from waterhyacinth, Cercospora piaropi Tharp, has been reported on waterhyacinths in Florida as causing an oval leaf spot by Freeman and Charudattan. Conidia measure x fl. Another species has also been isolated with larger conidia x 4-5 fl, and which also produces oval to irregular spots on waterhyacinth leaves, Pathogenicity-good location-rodman Reservoir, Lake Alice Date-December-May Ret-Freeman & Charudattan, 1974; Chupp, 1953, 16, CLADOSPORIUM spp. (Fig, 17) Cladosporium is a ubiquitous genus and a common saprophyte on waterhyacinth, it is easily diagnosed by its long chains of conidia and the branched ramo-conidia. 4

11 Pathogenicity-Not confirmed Location-ubiquitous Date-throughout investigation Ref.-M.B. Ellis, CURVULARIA spp. A. C. affinis Boedijn (Fig. 18) B. C. penniseti (Mitra) Boedijn (Fig. 19) Curvularia is a very common organism on waterhyacinth. Several species have been isolated and tested on waterhyacinth. Curvularia affinis is a saprophyte. Where as, C. penniseti produced a leaf spot in preliminary greenhouse studies. Pathogenicity-varies, usually none Location-Lake Alice, Rodman Reservoir Date-throughout study, abundant May Ref.-M. B. Ellis, DENDRYPHIELLA INFUSCANS (Thum) M.B. Ellis (Fig. 20) This organism occurred only a few times, usually on dead leaf material, in association with Alternaria, Cladosporium and Epicoccum. The distinguishing features of this genus are the tall conidiophore with terminal and intercalary nodose swellings and the branched chains of conidia. The conidia are brown, smooth, 0-2 septate and measure 9-16 x 4-7 fj.. Pathogenicity-not tested Location-Lake Alice Date-February Ref.-M.B. Ellis, EXSEROHILUM PROLA TUM Leonard & Suggs (Fig. 21) This species was isolated from a leaf spot on waterhyacinth. Exserohilum is a new genus derived from the Bipolaris group of the Helminthosporium complex. Exserohilum germinates from both ends of the conidium and the conidium possesses a protuberant hilum. Exserohilum proia tum is morphologically simi.lar to Exserohilum (Bipolaris) rostratum except E. prolatum lacks the heavy septations near the tip and base of the conidium. The conidium measures x fj.. Pathogenicity-under investigation Location-Lake Alice Date-May Ref.- Leonard & Suggs, MEMNONIELLA SUBSIMPLEX (Cke.) Deighton (Fig. 22) This organism is not encountered too frequently, however, when present it is usually in the saprophyte complex consisting of Alternaria, Cladosporium, Epicoccum and others. The long (130 fj.) hyaline conidiophore is terminated by 6-8 phialides, 8-9 x 2-3 fj.. Dark, sphaerical conidia, 6-8 fj. diam., are formed. Pathogenicity-not tested Location-Rodman Reservoir and Lake Alice Date-December Ref.-M.B. Ellis, PERICONIA BYSSOIDES Pers. ex Merat (Fig. 23) Periconia byssoides is also associated with the saprophyte complex occurring on waterhyacinth. The conidiophores are up to 1000 fj. long. The conidiophore is terminated by a cross wall near the tip producing a short apical cell. The conidiogenous cells are formed over the apex of this cell. The sphaerical conidia are verrucose, fj. in diam. Pathogenicity-slight Location-Rodman Reservoir, Lake Alice Date-January-February Ref.-M.B. Ellis, PITHOMYCES CHARTA RUM (Berk. & Curt.) M.B. Ellis (Fig, 24) The presence of this fungus is of critical importance to those attempting to produce a cattle feed from waterhyacinths. Pithomyces chartarum is a saprophyte usually found on senescent grasses and under the correct environmental conditions produces a toxin, sporidesmin, that can cause facial eczema of sheep and cattle, loss of weight, icterus and photosensitivity. The conidia contain the toxin and unless the toxin is inactivate, it could in certain periods of the year cause problems to cattle fed the waterhyacinth food stuff. Pathogenicity-Not confirmecl Location-Rodman Reservoir, Lake Alice Date-December-March Ref.-M.B. Ellis, NIGROSPORA A. Nigrospora oryzae (Berk. & Br.) Petch (Fig. 25) B. Nigrospora sphaerica (Sacc.) Mason (Fig. 26) Nigrospora sphaerica has been reported as a weak pathogen of waterhyacinth. Its performance is enhanced when used in combination with the waterhyacinth weevil (Neochetina). Nigrospora sphaerica has larger conidia (16-18 fj.) than N. oryzae (12-14 fj.). Pathogenicity-weak Location-Rodman Reservoir, Lake Alice, Fort Lauderdale, La Belle, Fla. area Date-January-February-May Ref.-M.B. Ellis, THYSANOPHORA LONGISPORA Kendrick (Fig. 27) Thysanophora longispora is a saprophyte found only on dead conifer needles in Canada. Its presence on waterhyacinth in Florida must be termed unusual. Conidiophores are over 1000 fj. long,metulae measure 20 fj., phialides x 7 fj., and conidia are catenulate, 9-14 x 3-4 fj.. The mycelium appears to be encrusted with crystals. Pathogenicity-Not determined Location-Lake Alice Date-January, March Ref.-Barron, SCOLECOBASIDIUM HUMICOLA Barron & Busch (Fig. 28) This organism is usually associated with the soil, particularly those high in organic matter. The conidia are two-celled, cylindrical, not constricted at the septum, finely echinulate and measure 7-15 x 2-4 fj.. The conidia are produced on tubular extensions of the conidiophore. Pathogenicity-not tested 5

12 location-lake Alice Date-February Ref.-M.B. Ellis, 1971; Barron, STEMPHYLIUM VESICARIUM (Wallr.) Simmons (Fig. 29) Initial greenhouse observations of the pathogenicity of this fungus indicate it may have a potential for control of waterhyacinth. The conidia are large, x /1, muriform, dark brown, and finely echinulate. Pathogenicity-slight location-la Belle, Fla. area Date-May Ref.-Simmons, 1969; M.B. Ellis, SPOROBOLOMYCES sp. (Fig. 30) This fungus has been observed several ti mes in cleared leaf section of waterhyacinth. It has not been cultured and, therefore, not much is known about the mode of conidial formation. A similar fungus has been isolated by Dr. Charudattan from the Dominican RepUblic. The conidia are about /1 in diam. Pathogenicity-not tested Location-Rodman Reservoir Date-December Ref.-Ellis,

13 Acknowledgements The authors are grateful for the help of Drs. j. W. Kimbrough and H.H. Luke in reviewing this paper. This research was supported by U.S. Army Corps of Engineers Contract No. DACW C-0049, Florida Department of Natural Resources and by the U.S. Department of Interior, Office of Water Resources as authorized by the Water Resources Act of Von Arx, J.A Beitra'ge zur kenntnis der gattung Mycosphaerella. Sydowia. 3: Von Arx, J.A The Genera of Fungi Sporulating in Pure Culture. J. Cramer. Lehre, Germany. 288 p. References 1. Barron, G. L The Genera of Hyphomycetes from soil. R.E. Krieger Publ. Co., New York, N.Y. 364 pp. 2. Chupp, C A Monograph of the Fungus Genus Cercospora. Ithaca, N.Y. 667 pp. 3. Corbaz, R Recherches Sur Ie genre Didymella Sacco Phytopath Z. 28: Dennis, R.W.G British Ascomycetes. J. Cramer, Lehre, Germany. 455 pp. 5. Doguet, G Le Genre "Melanospora"; Biologie, morphologie, Developpement, Systematique. Le Botaniste 39: Ellis, M.B Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, England. 608 pp. 7. Freeman, T.E., & R. Charudattan Occurrence of Cercospora piaropi on Waterhyacinth in Florida. Plant Dis. Reptr. 58: Gams, W Cephalosporiumartige Schimmelpilze (Hyphomycetes). G. Fischer Verlag. Stuttgart, Germany. 262 pp. 9. Hughes, S.J Revisiones Hyphomycetum aliquot cum Appendice de nominibus rijiciendis. Canad. J. Bot. 36: Leonard, K.J., & E.G. Suggs Setosphaeria prolata, The Ascigerous State of Exserohilum prolatum. Mycologia 66: Luttrell, E.s A Key to Species of Helminthosporium Reported on Grasses in the United States. Plan Dis. Reptr. SuppL 201 : Morris, E.F The Synnematous Genera of the Fungi Imperfecti. Western Illinois University, Macomb, III. Series p. 13. Morton, F.J., & G. Smith The Genera Scopulariopsis Bainier, Microascus Zukal, and Doratomyces Corda. CMI Mycological Papers, No Raper, K.B., & D.1. Fennel The Genus Aspergillus. 2nd ed. Williams and Wilkens Co., Baltimore. 686 p. 15. Rintz, R.E A Zonal Leaf Spot of Waterhyacinth caused by Cephalosporium zonatum. Hyacinth Control J. 11 : Simmons, E.G Perfect States of Stemphylium Mycologia 61 : Sutton, B.C Pucciniopsis, Mycoleptodiscus and Amerodiscosiella. Trans. Br. Mycol. Soc. 60:

14 Illustrations Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. Fig. 11. Fig. 12. Fig. 13. Fig. 14. Fig. 15. Fig. 16. Fig. 17. Fig. 18. Fig. 19. Fig. 20. Fig. 21. Fig. 22. Fig. 23. Fig. 24. Fig. 25. Fig. 26. Fig. 27. Fig. 28. Fig. 29. Fig. 30. Perithecia, asci (arrows) and ascospores of Melanospora Zamiae. X 100. Ascostroma, asci (bitunicate), and ascospores of Leptosphaerulina sp. X 150. Ascostroma of Didymella exigua. X 150. Ascostroma of Mycosphaerella Tassiana in a cross section of the leaf beneath a stoma. X 150. Pycnidium of Phoma sp. with extruded conidia. X 150. The neck of a pycnidium of Botryodiploidea sp. Note the presence of both one-celled, hyaline immature conidia and two-celled dark mature conidia. X 150. Cephalotrichum sp. X 150. Sporodochium and two-celled hyaline conidia of Mycoleptodiscus terrestris. X 150. Striated conidia of Myrothecium cintum. X 1,500. Sporodochium showing dark muriform conidia of Epicoccum purpurascens. X 150. Conidia of Alternaria sp. X 150. Conidial head of Aspergillus flavus. X 150. Conidial head of Aspergillus niger. X 150. Branched phialides and conidia of Acremonium zona tum (Cephalosporium). X 150. Conidia of Bipolaris cynodontis. X 150. A conidium of Cercospora sp. X 150. Branched conidial chain of Cladosporium sp. X 675. Conidia attached to conidiophore of Curvularia affinis. X 150. Conidia of Curvularia penniseti. X 150. Conidia and conidiophore of Dendryphiella infuscans. X 150. Conidium of Exserohilum prolatum. X 150. Conidiophore of Memnoniella subsimplex with phialidic conidiogenous cells and dark oval conidia. X 150. Conidiophore and conidia of Periconia byssoides. X 675. Muriform conidia of Pithomyces chartarum. X 150. Conidium of Nigrospora oryzae. Note the pedicel below the conidium. X 1,500. Conidium of Nigrospora sphaerica. X 1,500. Conidiophore, phial ides and conidia of Thysanophora longispora. X 150. Conidia of Scolecobasidium humicola. X 1,500. Conidium of Stemphylium vesicarium. X 675. Conidia of Sporobolomyces sp. within the epidermal cells of a waterhyacinth leaf. X

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