Schroers HJ et al. (2011), A revision of Cyanonectria and Geejayessia gen....

ECB-ART-41986

Stud Mycol 2011 Jan 01;68:115-38. doi: 10.3114/sim.2011.68.05.

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A revision of Cyanonectria and Geejayessia gen. nov., and related species with Fusarium-like anamorphs.

Schroers HJ , Gräfenhan T , Nirenberg HI , Seifert KA .

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A revision of Fusarium-like species associated with the plant genus Buxus led to a reconsideration of generic concepts in the Fusarium clade of the Nectriaceae. Phylogenetic analyses of the partial second largest subunit of the RNA polymerase II (rpb2) and the larger subunit of the ATP citrate lyase (acl1) gene exons confirm the existence of a clade, here called the terminal Fusarium clade, that includes genera such as Fusariumsensu stricto (including its Gibberella teleomorphs), Albonectria, Cyanonectria, "Haematonectria", the newly described genus Geejayessia, and "Nectria" albida. Geejayessia accommodates five species. Four were previously classified in Nectria sensu lato, namely the black perithecial, KOH-species G. atrofusca and the orange or reddish, KOH+ G. cicatricum, G. desmazieri and G. zealandica.Geejayessia celtidicola is newly described. Following our phylogenetic analyses showing its close relationship with Cyanonectria cyanostoma, the former Gibbera buxi is recombined as the second species of Cyanonectria. A three gene phylogenetic analysis of multiple strains of each morphological species using translation elongation factor 1 α (tef-1), rpb2 and acl1 gene exons and introns confirms their status as distinct phylogenetic species. Internal transcribed spacer of the ribosomal RNA gene cluster and nuclear large ribosomal subunit sequences were generated as additional DNA barcodes for selected strains. The connection of Fusarium buxicola, often erroneously reported as the anamorph of G. desmazieri, with the bluish black and KOH+ perithecial species C. buxi is reinstated. Most Cyanonectria and Geejayessia species exhibit restricted host ranges on branches or twigs of Buxus species, Celtisoccidentalis, or Staphyleatrifolia. Their perithecia form caespitose clusters on well-developed, mostly erumpent stromata on the bark or outer cortex of the host and are relatively thin-walled, mostly smooth, and therefore reminiscent of the more or less astromatous, singly occurring perithecia of Cosmospora, Dialonectria, and Microcera. The cell walls in outer- and inner layers of the perithecial walls of Cyanonectria and Geejayessia have inconspicuous pore-like structures, as do representative species of Albonectria, Fusarium sensu stricto, "Haematonectria", and "Nectria" albida. The taxonomic significance of these structures, which we call Samuels'' pores, is discussed.

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Genes referenced: btaf1 LOC100888242 LOC100893907 LOC105443556 LOC115919910 LOC115925415 LOC581235 LOC587157 LOC589952 polr3a sgpl1 snai2

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	Fig. 1. Phylogrammes showing generic relationships in the terminal Fusarium clade inferred from partial sequences of the second largest subunit of the RNA polymerase II and the larger subunit of ATP citrate lyase gene exons using Nectria cf. cinnabarina as outgroup. A. Majority rule consensus tree of a Bayesian Markov chain Monte Carlo sampling. B. One of 145 equally parsimonious trees. Numbers above branches are Bayesian posterior probabilities multiplied by 100 (p.p. > 90 are shown); those below lines are parsimony bootstrap proportions (> 70 % are shown). Fusarium sensu stricto is demarcated by a red frame, Geejayessia by green, Cyanonectria by blue, and the terminal Fusarium clade by yellow. Scale bars: A 0.05 substitutions per site, B 50 steps.
	Fig. 2. Phylogrammes showing individual gene phylogenies and combined phylogeny of species of Geejayessia and Cyanonectria. Majority rule consensus trees of Bayesian Markov chain Monte Carlo sampling inferred from introns and exons of the ATP citrate lyase (acl1, A), translation elongation factor 1 alpha (tef-1α, B), and the second largest subunit of the RNA polymerase II (rpb2, C). D. Phylogramme based on the combined data sets of the three genes. Numbers above branches are Bayesian posterior probabilities multiplied by 100 (p.p. > 90 are shown). Numbers below the branches are parsimony bootstrap proportions (> 70 % are shown). Scale bars: 0.04 substitutions per site.
	Fig. 3. Cyanonectria buxi, perithecia on the natural substrate. A–C. Habit on Buxus twigs. D–F. Colour change in perithecium in water (D), replaced with 2 % KOH (E) and then lactic acid (F), showing the reduced reaction towards the base of perithecium (E, F). G, H, J, K. Median longitudinal section through perithecia (G, H), ostiolar (J) and lateral perithecial walls (K). I. Longitudinal section through hyphal stroma supporting perithecia. L–O. Face view of perithecial wall. L. Hyphae covering perithecia reacting to lactic acid in a similar manner as the perithecium. M. Hypha-like cells on the surface of perithecia. N. Outermost cells of the main perithecial wall region with Samuels pores. O. Innermost cells of the perithecial wall. G–K in Shears; L in 2 % KOH; M–O in water. A, D–F, L–O CBS H-20380; B, C, G–K CBS H-20379. Scale bars: A–C = 500 μm; D (also applies to E, F), G = 100 μm; H = 50 μm; I–L 20 = μm; O (M, N) 10 = μm.
	Fig. 4. Cyanonectria buxi, spores and spore forming cells. A–D. Asci with a somewhat flattened apex, with or without a visible refractive ring. E, G, I–P. Ascospores. F, H. Ascospore surface. Q–S. Monophialides formed by immersed mycelium. T. Sporodochium. U–Y. Macroconidia. Z. Chlamydospores derived from macroconidium. AA–AC. Surface of PDA colonies after 14 d at 20, 25 and 30 °C. AD. Reverse of colony illustrated in AB. A–P CBS H-20379; Q–S. CBS 130.97; T, Y CBS 109638; U CBS 125554; V CBS 125551; W CBS 30.97; X, AA–AD BBA 64985; Z CBS 125547. A–P, from natural substrate. Q–Z, from SNA/B. Scale bars: B (also applies to A), X (W, Y) 50 = μm; C (D), Q (R, S), T 20 = μm; G (E, F, H), I (J–P), Z 10 = μm; U (V) = 50 and 10 μm; AA–AD = 10 mm.
	Fig. 5. Geejayessia cicatricum, perithecia on the natural substrate. A–C. Habit on decaying buds of Buxus sempervirens. D–F. Colour change in perithecium in water (D), replaced with 2 % KOH (E) and then lactic acid (F). G, H. Longitudinal section through decaying bud. I. Longitudinal section through stroma supporting the perithecia, with hypha-like cells. J–L. Median longitudinal sections through perithecia (J), ostiolar region (K) and lateral perithecial wall (L). M–O. Face views of perithecial wall. M. Cells on the surface of perithecia having hyphal or setose characteristics. N. Outermost cells of the main perithecial wall region with Samuels pores. O. Innermost cells of perithecial wall. C rehydrated in water, G–L in Shears, M, O in water, N in 2 % KOH. A, C, G–L, CBS H-20375; B, D–F, CBS H-20376; M–O, CBS H-20377. Scale bars: A–C, G = 500 μm; E (D, F) = 100 μm; H = 200 μm; I–L = 20 μm; M–O = 10 μm.
	Fig. 6. Geejayessia cicatricum, spores and spore forming cells. A–C. Asci with broadly rounded or slightly flattened apex, with visible refractive ring. D–J. Ascospores, with E, G showing surface roughening. K, L. Branched conidiophores and monophialides from sporodochia with anastomosing cells. M–Q. Macroconidia. A–J, M from natural substrate. K, N–Q from SNA, SNA/CL or SNA/B. L from PDA. A–J, L, CBS H-20374; K, N, P, Q, CBS 125549; M, CBS 125552; O, CBS 125550. Scale bars: A, O 50 = μm, B, C, K, L = 20 μm, G (applies also to D–F), I (H, J) = 10 μm, P (M, N, Q) = 50 and 10 μm.
	Fig. 7. Geejayessia atrofusca. A, B. Habit of perithecia on twigs of Staphylea trifolia. C, G, H. Longitudinal section through perithecial stroma (C), lateral perithecial wall (G), stroma composed of hypha-like cells (H). D–F. Colour change in perithecium in water (D), replaced with 2 % KOH (E) and then lactic acid (F). I. Hypha-like cells continuous with cells of the stroma covering base of perithecium. J, K. Face view of outermost cells of perithecial wall with Samuels pores (arrows). L. Ascus. M. Ascospores, the bottom one showing surface. N. Sporodochium. O, P. Mononematious, simple conidiophores, phialides. Q, R. Macroconidia. S, T. Aseptate or 1-septate microconidia. A–M, CBS H-20381, from natural substrate; N–T, CBS 125505 ex ascospores of CBS H-20381 on SNA/CL. Scale bars: A = 1 mm; B, C = 500 μm; D–F = 100 μm; G, J, K, M, O, P, S, T = 10 μm; H, I, L, N = 20 μm; Q, R = 50 and 5 μm.
	Fig. 8. Geejayessia celtidicola, perithecia on the natural substrate, holotype. A, B. Habit on bark of Celtis occidentalis. C, D. Colour change in perithecium in 2 % KOH (C) then replaced by lactic acid (D). E. Longitudinal section of erumpent stroma and perithecia. F–I. Face view of perithecial wall. F. Cells on the surface of perithecia showing hyphal or setose characteristics. G, H. Outermost cells of the main perithecial wall with Samuels pores. I. Intermediate cells of the perithecial wall. J–L. Median longitudinal sections of perithecia or perithecial walls. M. Longitudinal section through stroma supporting the perithecia showing hypha-like cells. B. after rehydration in water; E, H, J–M in Shears; F, G, I in water. Scale bars: A = 500 μm; B, E = 200 μm; C, D = 100 μm; F–I = 10 μm; J–M = 20 μm.
	Fig. 9. Geejayessia celtidicola, spores and spore forming cells. A–C. Asci with rounded apex, lacking refractive ring. D. Ascospore surface. E, F. Ascospores. G. Longitudinal section of sporodochium. H. Hymenial tissue of base of sporodochial stroma. I–K. Monophialides on branched conidiophores from sporodochial hymenium, I, J. With anastomoses. L–P. Macroconidia. A–F. Holotype CBS H-20378; G–K, P CBS 125502; L, M, O, CBS 125504; N, CBS 125481. Scale bars: A, B (applies also to C), N (L, M, O, P) = 50 μm; D (E, F) = 10 μm; G =100 μm; H, J (I, K) = 20 μm.
	Fig. 10. Geejayessia desmazieri, perithecia on the natural substrate. A–D. Habit on twigs of Buxus sempervirens. E–G. Colour change in perithecium in water (E), replaced with 2 % KOH (F) and then lactic acid (G). H–L. Longitudinal section through perithecial stroma (H), single perithecium (I), lateral perithecial wall (J), stroma with hypha-like cells (K), perithecial wall near ostiole (L). M, N. Hyphal or setose cells on the surface of perithecial wall. O–Q. Face view of outermost (O), intermediate (P) and innermost (Q) cell layers of perithecial wall. Arrows in O, P indicate Samuels pores in cell walls. H–L in Shears; M–Q in water. A, BPI 798402, isotype of N. desmazieri; B, M–O CBS H-20373; C, Q W-10342, isotype of N. gibbera; D–L, P, CBS H-20372, epitype; Q, “Funghi. rh. 2357, Fuckel 852”. Scale bars: A–D = 500 μm; E–G = 100 μm; H = 200 μm; I = 50 μm; J–L = 20 μm; M–Q = 10 μm.
	Fig. 11. Geejayessia desmazieri, spores and spore forming cells. A–C. Asci with broadly rounded or slightly flattened apex, lacking or with inconspicuous refractive rings. D. Ascospore surface. E. Ascospores. F. Branched conidiophores from sporodochia. G, N. Hymenium of monophialides from sporodochia. H–M, O–V. Macroconidia from sporodochia. A–E, N, O–V, from natural substrate. F–M, from SNA/B or SNA/CL. A–C, CBS H-20372, epitype of G. desmazieri; D, E, CBS H-20373; F, G, L, M, CBS 840.85; H–J, BBA 67515; K, CBS 125507, ex-epitype strain; N–V, G00110886, lectotype of N. gibbera. N, S–V, mounted in lactic acid, all others in water. Scale bars: B (also applies to A, C), H (I–M, O–V) = 50 μm; D, E = 10 μm; F, G (N) = 20 μm; O (H–M, P–V) = 5 μm.
	Fig. 12. Comparison of teleomorph characters of “Haematonectria” illudens, “Haematonectria” sp. and “Nectria” albida. A–I. “Haematonectria” illudens on the natural substrate. A. Habit of perithecia. B–D. Longitudinal sections of perithecia, erumpent stroma and lateral perithecial wall. E–G. Front view of cell layers of the perithecial wall, E, F showing cells of perithecial warts. H, I. Ascospore, H showing surface striations. J–P. “Haematonectria” sp. J–L. Colour changes in perithecium mounted in water (J), replaced with 2 % KOH (K) and then lactic acid (L). M. Habit of perithecia. N. Cells of perithecial warts. O, P. Intermediate cells of the perithecial wall. Q–X. “Nectria” albida. Q. Habit of perithecia. R–T. Colour changes in perithecium mounted in water (R), replaced with 2 % KOH (S) and then lactic acid (T). U. Ascospore. V. Short seta like cells emerging from perithecial wall. W. Hypha-like cells probably continuous with cells of the stroma covering base of perithecium. X. Outermost cell layer of perithecial wall. Arrows in E–G, N–P, X indicate Samuels pores in cell-walls. A–I BPI 802461; J–P BPI 745186; Q–X BPI 1108875. Scale bars: A, Q = 500 μm; B, J–L, R–T = 100 μm; C, D = 50 μm; E–I, N–P, U–X = 10 μm; M = 200 μm.
	Fig. 13. Comparison of teleomorph characters of Fusarium sambucinum and Albonectria rigidiuscula. A–J. Fusarium sambucinum on the natural substrate. A–C. Habit of perithecia. D–F. Colour changes in perithecium mounted in water (D), replaced with 2 % KOH (E) and then with lactic acid (F). G–I. Face view of cell layers of the perithecial wall. G. Cells of perithecial warts. I. Innermost cells of the perithecial wall. K–U. Albonectria rigidiuscula. K–M. Colour changes in perithecium mounted in water (K), replaced with 2 % KOH (L) and then with lactic acid (M). N, O. Habit of perithecia. P, Q. Cells of perithecial warts. R. Cells of the main perithecial wall. S–U. Ascospores, U showing wall surface. Arrows in H, I, P–R indicate Samuels pores in cell walls. A, B, D–F HJS 1459; C, G–J BPI 1109327; K–U HJS 0109. Scale bars: A = 1 mm; B, C, N, O = 500 μm; D–F, K–M = 100 μm; G = 20 μm; H–J, P–U = 10 μm.

References [+] :

Chaverri, Delimitation of Neonectria and Cylindrocarpon (Nectriaceae, Hypocreales, Ascomycota) and related genera with Cylindrocarpon-like anamorphs. 2011, Pubmed, Echinobase