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Mimema venturae sp. nov. on Dalbergia miscolobium in Brazil
Mycol. Res. 98 (7): 786-788 (1994)
786
Printed in Great Britain
Mimema venturae sp. nov. on Dalbergia miscolobium in Brazil
JOSE C. DIANESE, LEILA T. P. SANTOS, RICARDO B. MEDEIROS AND MARIZA SANCHEZ Departamento de Fitopatologia, Universidade de BrasJ1ia, 70910-900 Brasz1ia, DF, Brazil
Mimema venturae sp. nov. is described on Dalbergia miseolobium collected in the Brazilian cerrado and the status of Minema is discussed.
Mimema venturae Dianese, L. T. P. Santos, R. B. Medeiros & M. Sanchez sp. nov. (Figs. 1-4) £tym.: After Manuel Mateus Ventura, Brazilian biophysicist from Fortaleza, Ceara. Spermogonia et aeeia ignota. Uredinia hypophylla, 0'1-0'15 mm diam., sparsa, vel gregaria, subepidermalia, erumpentia, valde paraphysibus peripheralibus; paraphyses cylindricae, incurvatae, 40--72 x 5-8 ~m. Urediniosporae obovoideae, subglobosae vel pyriformes, pedicellatae, 22-27 x 12-15 ~m, mebrana ea 1-2 ~m crassa, flavida, echinulata, poris germinationis 1-2. Sorus teleutosporijer in anamorphis formantis, hypophyllus, caespitosus, filiformis, usque 1-1'5 mm longus x 2336 ~ latus, flavidus; teleutosporae fusiformes, 80--195 ~ longae x 8-10 ~ latae, (3-)4(-6)-septate, ad septa plerumque constritae, episporio hyalino 0'5-1 ~m crasso, appendice basale hyalino, 20--26 ~m longo x 2-3 ~ lato, cum functione conjuctivo, cellulis intermediis 10--13 ~ longis x 4-6 ~m latis, cellula superioribus longioribus (24-30 ~m longa x 4-6 ~m lata); metabasidium cylindracum, 35-50 x 4-5 ~ membrana crassa, hyalina; basidiosporae obovoideae (4'5-5 x 5-6 ~). In foliis vivis Dalbergiae miseolobii (Leguminosae) in urbe Brazlandia, Distrito Federal, Brasil, J. C. Dianese lectus, holotypus UB-1315, collectio mycologica.
Spermogonia and aecia not known. Uredinia subepidermaL 0'10'15 mm diam., light brown, hypophyllous, sparse, erumpent, pulverulent, paraphysate. Paraphyses, 40-72 X 5-8 I-lffi, hyaline, peripheraL straight-cylindrical with rounded tip to sickle shaped with a thicker outer walL nonseptate or with a septum close to the base, sometimes covering most of the lumen of the uredinia (Fig. 1 A-B). Urediniospores obovoid, subgloboid to pyriform, light brown, with truncate base, pedicellate, 22-27 x 12-15 !-lm (Fig. lA-B), walls 1-2 f.lm thick, echinulate, sometimes originated sympodially from sporogenous cells, with 1-2 equatorial germ-pores (Fig. lA-B). Telia formed from within the uredinia, filiform with large numbers of peripheral paraphyses at the bases of the telial threads (1-1'5 mm long x 23-36 (..lm wide) (Fig. 2 A-D). Teliospores (3-)4(-6)-septate, 80-195 x 8-10 f.lm (Fig. 2 A-D), when germinating each cell gives rise to a 4-celled metabasidium (Fig. 3 A-e) with four basidiospores, except for the pedicel which functions as a conjugative structure to form the ropelike columns (Fig. 2 D). This pedicel tapers to a thin sticky appendix which is responsible for the lateral connections among teliospores (Fig. 2 D) or connection of any teliospore
Fig. 1 (A-B). Uredinia of Mimema venturae showing a densely paraphysate periphery (bars = 10 ~m).
J. C. Dianese and others
787
Fig. 2. A, Telial columns of Mimema venturae with paraphyses at the base (bar = 100 1JIl1); B, Detail of the telial base (bar = 10 j,lm); C Teliospores and uredinoiospores seen in light microscope and D, Telium showing (arrow) the connective role of the basal appendix of the teliospore also laterally joining two teliospores (bars = 20 j,lm).
with the one fonned just below it in the column (Fig. 4) and results in the production of yarn-like columns. The spores are not catenate instead they form columns through external interactions. Jackson (1931) described Mimema H. S. Jacks. on Cassia sp. (Leguminosae) and Allopuccinia H. S. Jacks. on Amicia sp. (Leguminosae) from Bolivia. Spermogonia have never been observed in Mimema but the similarity between its uredinia and those of Allopuccinia is clear Oackson, 1931). Later, Thirumalachar & Cummins (1948) placed Allopuccinia as a
synonym of Soratea Syd. (Sydow, 1930) based on host family, uredinal and telial morphology and identity of the spermogonial type. Cummins & Hiratsuka (1983), also considered Mimema a synonym of Soratea (Uropyxidaceae) although no spermogonium was ever observed on Mimema Oackson, 1931). Its teliospores are much different from those of soratea which form mostly 2-celled, rarely 3-celled, teliospores with the distal cell germinating at the apex (Cummins & Hiratsuka, 1983) while in Mimema teliospores are mostly multiseptate, stipitate with the distal cell germinating sub-apically (Fig. 3 C). 50·2
Mimema venturae sp. nov. on Dalbergia miscolobium
788
Fig. 4. Role of the teliosporic basal-appendix of Mimema venturae, formed as a continuation of the pedicel, on the interaction between two teliospores in a column as seen in detailed light-microscopic view (bar = 10 ~m).
Fig. 3. A-C Germinating teliospores of Mimema venturae showing the formation of metabasidium from the beginning (A), going through the formation of septa (B) to the production of sterigmata and basidiospore (C) which also shows that the germination of the distal cell occurs subapically (bars = 10 1J.ffi).
M. venturae clearly forms telia from inside old uredinia while this was never reported in soratea. Cummins & Hiratsuka (1983) placed Mimema and also Leucotelium Tranzschel (heteroecious rust fungus with spermogonia and aecidia on Ranunculaceae and uredinia and telia on Rosaceae) as syonyms of Soratea which is autoecious on Leguminosae (Eboh & Cummins, 1980; Cummins & Hiratsuka, 1983). The argument used to include Leucotelium in Soratea was that both genera have subcuticular spermogonium but in Mimema this is still not known to occur because Jackson (193 I) simply speculated that the spermogonia of Mimema were 'probably subcuticular'. Both Mimema and Soratea form teliospores from a hymenial layer which is not per se a characteristic strong enough to combine or segregate genera as indicated by Thirumalachar & Cummins (1948). On the other hand, the morphology of the telia, teliospores, uredinia and urediniospores of Mimena is identical to that of (Accepled 4 January 1994)
Hamaspora Korn. (Monoson, 1969) known only on species of Rubus (Rosaceae). This fact was promptly accepted by Jackson (1931) who even suggested Hamaspora holwayi H. S. Jacks. as an alternative name for M. holwayi H. S. Jacks., the type species of Mimema. Hamaspora and Mimema, both from tropical or warm areas, apparently evolved following parallel lines on unrelated hosts. However, if they are found to have the same spermogonial type then Hamaspora will be the correct name for the genus based on the principle of priority. Furthermore, Hamaspora has subcuticular spermogonia type 8 or 10 and not type 7 as in Soratea and this difference has been considered as sufficient to segregate the two genera (Cummins & Hiratsuka, 1983). Following this same reasoning it becomes presently impossible to consider Mimema as a synonym of soratea until more data on spermogonial morphology are available because both genera are clearly different in terms of telial and teliospore morphology. The present species is, therefore, referred to Mimema rather than Soratea thus rejecting the generic synonymy proposed by Cummins & Hiratsuka (1983). It differs from M. holwayi, the only species in the previously monotypic Mimema, in host preference, the conspicuous telial columns (up to 1'5 mm long) composed of longer teliospores, larger uredinial paraphyses and larger more pyriform urediniospores.
REFERENCES Cummins, G. B. & Hiratsuka, Y. (1983). IlIuslraled genera of rusl fungi. American Phytopathological Society: St PauL MN. Durrieu, G. 1975. Deux nouveaux Hamaspora de L'Himalaya. Mycotaxon 2, 205-208. Eboh, D. O. & Cummins, G. B. (1980). Species of Soralea (Uredinales). Mycologia 72, 203-204. Hennen, J. F., Hennen, M. M. & Figueiredo M. B. (1982). Indice de ferrugens (Uredinales) do Brasil. Arquivos Insliluto Biol6gico Sao Paulo 49 (Suppl. I), 1-201. Jackson, H. S. (1931). The rusts of South America based on the Holway collections. IV. Mycologia 23, 332-364. Moroson, H. L. (1969). The species of Hamaspora. Mypathologia eI Mycologia Applicata 37, 263-272. Sydow, H. (1930). Novae fungorum species. XX. Annales Mycologici 28, 432-447. Thirumalachar, M. J. & Cummins, G. B. (1948). Status of the rust genera Allopuccinia, Leucolhelium, Edylhea, and Ypsilospora. Mycologia 40,417-422.
786
Printed in Great Britain
Mimema venturae sp. nov. on Dalbergia miscolobium in Brazil
JOSE C. DIANESE, LEILA T. P. SANTOS, RICARDO B. MEDEIROS AND MARIZA SANCHEZ Departamento de Fitopatologia, Universidade de BrasJ1ia, 70910-900 Brasz1ia, DF, Brazil
Mimema venturae sp. nov. is described on Dalbergia miseolobium collected in the Brazilian cerrado and the status of Minema is discussed.
Mimema venturae Dianese, L. T. P. Santos, R. B. Medeiros & M. Sanchez sp. nov. (Figs. 1-4) £tym.: After Manuel Mateus Ventura, Brazilian biophysicist from Fortaleza, Ceara. Spermogonia et aeeia ignota. Uredinia hypophylla, 0'1-0'15 mm diam., sparsa, vel gregaria, subepidermalia, erumpentia, valde paraphysibus peripheralibus; paraphyses cylindricae, incurvatae, 40--72 x 5-8 ~m. Urediniosporae obovoideae, subglobosae vel pyriformes, pedicellatae, 22-27 x 12-15 ~m, mebrana ea 1-2 ~m crassa, flavida, echinulata, poris germinationis 1-2. Sorus teleutosporijer in anamorphis formantis, hypophyllus, caespitosus, filiformis, usque 1-1'5 mm longus x 2336 ~ latus, flavidus; teleutosporae fusiformes, 80--195 ~ longae x 8-10 ~ latae, (3-)4(-6)-septate, ad septa plerumque constritae, episporio hyalino 0'5-1 ~m crasso, appendice basale hyalino, 20--26 ~m longo x 2-3 ~ lato, cum functione conjuctivo, cellulis intermediis 10--13 ~ longis x 4-6 ~m latis, cellula superioribus longioribus (24-30 ~m longa x 4-6 ~m lata); metabasidium cylindracum, 35-50 x 4-5 ~ membrana crassa, hyalina; basidiosporae obovoideae (4'5-5 x 5-6 ~). In foliis vivis Dalbergiae miseolobii (Leguminosae) in urbe Brazlandia, Distrito Federal, Brasil, J. C. Dianese lectus, holotypus UB-1315, collectio mycologica.
Spermogonia and aecia not known. Uredinia subepidermaL 0'10'15 mm diam., light brown, hypophyllous, sparse, erumpent, pulverulent, paraphysate. Paraphyses, 40-72 X 5-8 I-lffi, hyaline, peripheraL straight-cylindrical with rounded tip to sickle shaped with a thicker outer walL nonseptate or with a septum close to the base, sometimes covering most of the lumen of the uredinia (Fig. 1 A-B). Urediniospores obovoid, subgloboid to pyriform, light brown, with truncate base, pedicellate, 22-27 x 12-15 !-lm (Fig. lA-B), walls 1-2 f.lm thick, echinulate, sometimes originated sympodially from sporogenous cells, with 1-2 equatorial germ-pores (Fig. lA-B). Telia formed from within the uredinia, filiform with large numbers of peripheral paraphyses at the bases of the telial threads (1-1'5 mm long x 23-36 (..lm wide) (Fig. 2 A-D). Teliospores (3-)4(-6)-septate, 80-195 x 8-10 f.lm (Fig. 2 A-D), when germinating each cell gives rise to a 4-celled metabasidium (Fig. 3 A-e) with four basidiospores, except for the pedicel which functions as a conjugative structure to form the ropelike columns (Fig. 2 D). This pedicel tapers to a thin sticky appendix which is responsible for the lateral connections among teliospores (Fig. 2 D) or connection of any teliospore
Fig. 1 (A-B). Uredinia of Mimema venturae showing a densely paraphysate periphery (bars = 10 ~m).
J. C. Dianese and others
787
Fig. 2. A, Telial columns of Mimema venturae with paraphyses at the base (bar = 100 1JIl1); B, Detail of the telial base (bar = 10 j,lm); C Teliospores and uredinoiospores seen in light microscope and D, Telium showing (arrow) the connective role of the basal appendix of the teliospore also laterally joining two teliospores (bars = 20 j,lm).
with the one fonned just below it in the column (Fig. 4) and results in the production of yarn-like columns. The spores are not catenate instead they form columns through external interactions. Jackson (1931) described Mimema H. S. Jacks. on Cassia sp. (Leguminosae) and Allopuccinia H. S. Jacks. on Amicia sp. (Leguminosae) from Bolivia. Spermogonia have never been observed in Mimema but the similarity between its uredinia and those of Allopuccinia is clear Oackson, 1931). Later, Thirumalachar & Cummins (1948) placed Allopuccinia as a
synonym of Soratea Syd. (Sydow, 1930) based on host family, uredinal and telial morphology and identity of the spermogonial type. Cummins & Hiratsuka (1983), also considered Mimema a synonym of Soratea (Uropyxidaceae) although no spermogonium was ever observed on Mimema Oackson, 1931). Its teliospores are much different from those of soratea which form mostly 2-celled, rarely 3-celled, teliospores with the distal cell germinating at the apex (Cummins & Hiratsuka, 1983) while in Mimema teliospores are mostly multiseptate, stipitate with the distal cell germinating sub-apically (Fig. 3 C). 50·2
Mimema venturae sp. nov. on Dalbergia miscolobium
788
Fig. 4. Role of the teliosporic basal-appendix of Mimema venturae, formed as a continuation of the pedicel, on the interaction between two teliospores in a column as seen in detailed light-microscopic view (bar = 10 ~m).
Fig. 3. A-C Germinating teliospores of Mimema venturae showing the formation of metabasidium from the beginning (A), going through the formation of septa (B) to the production of sterigmata and basidiospore (C) which also shows that the germination of the distal cell occurs subapically (bars = 10 1J.ffi).
M. venturae clearly forms telia from inside old uredinia while this was never reported in soratea. Cummins & Hiratsuka (1983) placed Mimema and also Leucotelium Tranzschel (heteroecious rust fungus with spermogonia and aecidia on Ranunculaceae and uredinia and telia on Rosaceae) as syonyms of Soratea which is autoecious on Leguminosae (Eboh & Cummins, 1980; Cummins & Hiratsuka, 1983). The argument used to include Leucotelium in Soratea was that both genera have subcuticular spermogonium but in Mimema this is still not known to occur because Jackson (193 I) simply speculated that the spermogonia of Mimema were 'probably subcuticular'. Both Mimema and Soratea form teliospores from a hymenial layer which is not per se a characteristic strong enough to combine or segregate genera as indicated by Thirumalachar & Cummins (1948). On the other hand, the morphology of the telia, teliospores, uredinia and urediniospores of Mimena is identical to that of (Accepled 4 January 1994)
Hamaspora Korn. (Monoson, 1969) known only on species of Rubus (Rosaceae). This fact was promptly accepted by Jackson (1931) who even suggested Hamaspora holwayi H. S. Jacks. as an alternative name for M. holwayi H. S. Jacks., the type species of Mimema. Hamaspora and Mimema, both from tropical or warm areas, apparently evolved following parallel lines on unrelated hosts. However, if they are found to have the same spermogonial type then Hamaspora will be the correct name for the genus based on the principle of priority. Furthermore, Hamaspora has subcuticular spermogonia type 8 or 10 and not type 7 as in Soratea and this difference has been considered as sufficient to segregate the two genera (Cummins & Hiratsuka, 1983). Following this same reasoning it becomes presently impossible to consider Mimema as a synonym of soratea until more data on spermogonial morphology are available because both genera are clearly different in terms of telial and teliospore morphology. The present species is, therefore, referred to Mimema rather than Soratea thus rejecting the generic synonymy proposed by Cummins & Hiratsuka (1983). It differs from M. holwayi, the only species in the previously monotypic Mimema, in host preference, the conspicuous telial columns (up to 1'5 mm long) composed of longer teliospores, larger uredinial paraphyses and larger more pyriform urediniospores.
REFERENCES Cummins, G. B. & Hiratsuka, Y. (1983). IlIuslraled genera of rusl fungi. American Phytopathological Society: St PauL MN. Durrieu, G. 1975. Deux nouveaux Hamaspora de L'Himalaya. Mycotaxon 2, 205-208. Eboh, D. O. & Cummins, G. B. (1980). Species of Soralea (Uredinales). Mycologia 72, 203-204. Hennen, J. F., Hennen, M. M. & Figueiredo M. B. (1982). Indice de ferrugens (Uredinales) do Brasil. Arquivos Insliluto Biol6gico Sao Paulo 49 (Suppl. I), 1-201. Jackson, H. S. (1931). The rusts of South America based on the Holway collections. IV. Mycologia 23, 332-364. Moroson, H. L. (1969). The species of Hamaspora. Mypathologia eI Mycologia Applicata 37, 263-272. Sydow, H. (1930). Novae fungorum species. XX. Annales Mycologici 28, 432-447. Thirumalachar, M. J. & Cummins, G. B. (1948). Status of the rust genera Allopuccinia, Leucolhelium, Edylhea, and Ypsilospora. Mycologia 40,417-422.