Diversity and potential impact of Calonectria species in Eucalyptus plantations in Brazil

Abstract

Species in the genus Calonectria (Hypocreales) represent an important group of plant pathogenic fungi that cause serious losses to plant crops in tropical and subtropical climates. Calonectria leaf blight is currently one of the main impediments to Eucalyptus cultivation in Brazil, and various species of Calonectria have been associated with this disease. Since most previous identifications were solely based on morphological characters, much of the published literature needs to be re-evaluated. The aim of this study was thus to identify and determine the phylogenetic relationships among species that occur in the Eucalyptus growing regions of Brazil by using partial sequences of the β-tubulin, calmodulin, translation elongation factor 1-α and histone H3 gene regions. Based on extensive collections from soil and infected eucalypt leaf samples from plantations, phylogenetic inference revealed the Ca. pteridis complex to be the most common species complex present in Eucalyptus plantations in Brazil. By elucidating taxa in the Ca. pteridis, Ca. cylindrospora and Ca. candelabra species complexes, 20 novel Calonectria species were identified, and a new name in Calonectria provided for Cylindrocladium macrosporum as Ca. pseudopteridis.

Keywords: Ca. duoramosa R.F. Alfenas, L. Lombard & Crous; Ca. eucalypticola R.F. Alfenas, L. Lombard & Crous; Ca. glaebicola R.F. Alfenas, L. Lombard & Crous; Ca. maranhensis R.F. Alfenas, L. Lombard & Crous; Ca. metrosideri R.F. Alfenas, O.L. Pereira, Crous & A.C. Alfenas; Ca. multinaviculata R.F. Alfenas, L. Lombard & Crous; Ca. nemuricola R.F. Alfenas, L. Lombard & Crous; Ca. paraensis R.F. Alfenas, L. Lombard & Crous; Ca. piauiensis R.F. Alfenas, L. Lombard & Crous; Ca. propaginicola R.F. Alfenas, L. Lombard & Crous; Ca. pseudobrassicae R.F. Alfenas, L. Lombard & Crous; Ca. pseudocerciana R.F. Alfenas, L. Lombard & Crous; Ca. pseudohodgesii R.F. Alfenas, L. Lombard & Crous; Ca. pseudometrosideri R.F. Alfenas, L. Lombard & Crous; Ca. pseudopteridis (Sherb.) R.F. Alfenas, L. Lombard & Crous; Ca. pseudospathulata R.F. Alfenas, L. Lombard & Crous; Ca. pseudovata R.F. Alfenas, L. Lombard & Crous; Ca. quinqueramosa R.F. Alfenas, L. Lombard & Crous; Ca. robigophila R.F. Alfenas, L. Lombard & Crous; Ca. silvicola R.F. Alfenas, L. Lombard & Crous; Ca. telluricola R.F. Alfenas, L. Lombard & Crous; Calonectria brassiana R.F. Alfenas, L. Lombard & Crous; Calonectria leaf blight; Cylindrocladium; Damping-off; Diversity; Taxonomy.

Fig. 1

Consensus phylogram of 2 439 trees resulting from a Bayesian analysis of the combined four gene sequence alignment of the Calonectria brassicae and Ca. pteridis complexes. Accession numbers in bold represent ex-type strains. Bayesian posterior probabilities and Maximum Parsimony bootstrap support values are indicated at the nodes and the scale bar represents the number of expected changes per site. The tree was rooted to Ca. colombiensis (CBS 112220, CBS 112221).

Fig. 2

Consensus phylogram of 1 480 trees resulting from a Bayesian analysis of the combined four gene sequence alignment of the Calonectria cylindrospora complex. Accession numbers in bold represent ex-type strains. Bayesian posterior probabilities and Maximum Parsimony bootstrap support values are indicated at the nodes and the scale bar represents the number of expected changes per site. The tree was rooted to Ca. colombiensis (CBS 112220, CBS 112221).

Fig. 3

Consensus phylogram of 15 trees resulting from a Bayesian analysis of the combined four gene sequence alignment of the Calonectria naviculata complex. Accession numbers in bold represent ex-type strains. Bayesian posterior probabilities and Maximum Parsimony bootstrap support values are indicated at the nodes and the scale bar represents the number of expected changes per site. The tree was rooted to Ca. colombiensis (CBS 112220, CBS 112221).

Fig. 4

Consensus phylogram of 2 348 trees resulting from a Bayesian analysis of the combined four gene sequence alignment of the Calonectria candelabra complex. Accession numbers in bold represent ex-type strains. Bayesian posterior probabilities and Maximum Parsimony bootstrap support values are indicated at the nodes and the scale bar represents the number of expected changes per site. The tree was rooted to Ca. colombiensis (CBS 112220, CBS 112221).

Fig. 5

Calonectria brassiana (ex-type CBS 134855). A–C. Macroconidiophores. D–E. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. F–G. Ellipsoidal to narrowly obpyriform vesicles. H–I. Macroconidia. Scale bars: A = 50 μm (apply to B); C = 20 μm; D = 10 μm (apply to F, H); E = 10 μm (apply to G, I).

Fig. 6

Calonectria duoramosa (ex-type CBS 134656). A–C. Macroconidiophores. D–F. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. G–I. Clavate vesicles. J–K. Macroconidia. Scale bars: A = 50 μm; B = 50 μm (apply to C); D = 10 μm (apply to E–K).

Fig. 7

Calonectria eucalypticola (ex-type CBS 134847). A–C. Macroconidiophores. D. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. E–F. Ellipsoidal to obpyriform vesicles. G. Macroconidia. Scale bars: A = 50 μm (apply to B–C); D = 10 μm; E = 10 μm (apply to F); G = 10 μm.

Fig. 8

Calonectria glaebicola (ex-type CBS 134852). A–C. Macroconidiophores. D–E. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. F–G. Ellipsoidal to narrowly obpyriform vesicles. H. Macroconidia. I. Chlamydospores. Scale bars: A = 50 μm (apply to B–C); D = 10 μm (apply to E–I).

Fig. 9

Calonectria maranhensis (ex-type CBS 134811). A–C. Macroconidiophores. D–F. Ellipsoidal, obpyriform to sphaeropedunculate vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 20 μm (apply to B–C); D = 10 μm (apply to E–F); G = 10 μm (apply to H–I).

Fig. 10

Calonectria multinaviculata (ex-type CBS 134858). A–C. Macroconidiophores. D–F. Naviculate vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 50 μm (apply to B–C); D = 10 μm (apply to E–I).

Fig. 11

Calonectria nemuricola (ex-type CBS 134837). A–C. Macroconidiophores. D–F. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. G–H. Obpyriform vesicles. I. Macroconidia. Scale bars: A = 100 μm; B = 50 μm (apply to C); D = 10 μm (apply to E–F); G = 10 μm (apply to H–I).

Fig. 12

Calonectria paraensis (ex-type CBS 134669). A–C. Macroconidiophores. D–E. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. F. Macroconidia. G–I. Clavate vesicles. Scale bars: A = 50 μm (apply to B–C); D = 10 μm (apply to E–I).

Fig. 13

Calonectria piauiensis (ex-type CBS 134850). A–C. Macroconidiophores. D–F. Ellipsoidal to narrowly obpyriform vesicles. G. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. H. Macroconidia. I. Chlamydospores. Scale bars: A = 100 μm; B = 50 μm (apply to C, I); D = 10 μm (apply to E–F); G = 10 μm (apply to H).

Fig. 14

Calonectria propaginicola (ex-type CBS 134815). A–C. Macroconidiophores. D–F. Ellipsoidal, obpyriform to sphaeropedunculate vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 50 μm (apply to B–C); D = 10 μm (apply to E–I).

Fig. 15

Calonectria pseudobrassicae (ex-type CBS 134662). A–C. Macroconidiophores. D–F. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. G–H. Clavate vesicles. I. Macroconidia. Scale bars: A = 100 μm (apply to B); C = 50 μm; D = 10 μm (apply to E–I).

Fig. 16

Calonectria pseudocerciana (ex-type CBS 134824). A–C. Macroconidiophores. D–F. Obpyriform to sphaeropedunculate vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 50 μm (apply to B–C); D = 10 μm (apply to E–I).

Fig. 17

Calonectria pseudohodgesii (ex-type CBS 134818). A–C. Macroconidiophores. D–F. Ellipsoidal to obpyriform vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 100 μm; B = 50 μm (apply to C); D = 10 μm (apply to E–F, H–I); G = 20 μm.

Fig. 18

Calonectria pseudometrosideri (ex-type CBS 134845). A–C. Macroconidiophores. D–F. Ellipsoidal to obpyriform vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 50 μm (apply to B, G); D = 10 μm (apply to E–F, H–I).

Fig. 19

Calonectria pseudospathulata (ex-type CBS 134841). A–C. Macroconidiophores. D–F. Obpyriform vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 50 μm (apply to B–C); D = 10 μm (apply to G–I); E = 10 μm (apply to F).

Fig. 20

Calonectria pseudovata (ex-type CBS 134674). A–C. Macroconidiophores. D–F. Ovate to ellipsoidal vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. J–K. Microconidiophores. L. Microconidia. Scale bars: A = 50 μm (apply to B); C = 50 μm; D = 10 μm (apply to E–F, H–I); G = 10 μm (apply to J–L).

Fig. 21

Calonectria quinqueramosa (ex-type CBS 134654). A. Ascoma. B–C. Vertical section through ascomata, showing wall structure. D–E. Asci. F. Ascospores. G–I. Macroconidiophores. J–L. Narrowly clavate to clavate vesicles. M–N. Conidiogenous apparatus with conidiophore branches, doliiform to reniform phialides. O. Macroconidia. Scale bars: A = 500 μm; B = 100 μm (apply to C); D = 50 μm (apply to I); E = 20 μm (apply to F, J–O); G = 50 μm (apply to H).

Fig. 22

Calonectria robigophila (ex-type CBS 134652). A–C. Macroconidiophores. D–F. Clavate vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars: A = 50 μm; B = 50 μm (apply to C); D = 10 μm (apply to I); E = 10 μm (apply to F–H).

Fig. 23

Calonectria silvicola (ex-type CBS 135237). A–C. Macroconidiophores. D–F. Obpyriform vesicles. G–H. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. I. Macroconidia. Scale bars A = 100 μm; B = 50 μm (apply to C); D = 10 μm (apply to E–I).

Fig. 24

Calonectria telluricola (ex-type CBS 134664). A–C. Macroconidiophores. D. Clavate vesicle. E. Conidiogenous apparatus with conidiophore branches and doliiform to reniform phialides. F. Macroconidia. Scale bars: A = 100 μm (apply to B); C = 20 μm; D = 10 μm (apply to E–F).