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Ascus apical apparatus and ascospore characters in Xylariaceae.

Suwannasai N, Whalley MA, Whalley AJ, Thienhirun S, Sihanonth P - IMA Fungus (2012)

Bottom Line: Camillea is for example, instantly recognizable by its rhomboid or diamond shaped apical apparatus, and the distinctive inverted hat or urniform type is usually prominent in Xylaria, Rosellinia, Kretzschmaria, and Nemania.At least six categories of apical apparatus based on shape and size can be recognized.Ascospore ornamentation as seen by SEM has been exceptionally useful and provided the basis for separating Camillea from Biscogniauxia and other xylariaceous genera.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology (Microbiology), Faculty of Science, Srinakharinwirot University, 114 Sukhumvit 23, Bangkok, 10110, Thailand;

ABSTRACT
Members of Xylariaceae (Ascomycota) are recognized and classified mainly on the morphological features of their sexual state. In a number of genera high morphological variation of stromatal characters has made confident recognition of generic and specific boundaries difficult. There are, however, a range of microscopical characteristics which can in most cases make distinctions, especially at generic level, even in the absence of molecular data. These include details of the apical apparatus in the ascus (e.g. disc-shaped, inverted hat-shaped, rhomboid, composed of rings, amyloid, non-amyloid); position and length of the germ slit; and presence and type of ascospore wall ornamentation as seen by scanning electron microscopy (SEM). Unfortunately many of the classical studies on xylariaceous genera omitted these features and were undertaken long before the development of scanning electron microscopy. More recent studies have, however, demonstrated their value as diagnostic characters in the family. Camillea is for example, instantly recognizable by its rhomboid or diamond shaped apical apparatus, and the distinctive inverted hat or urniform type is usually prominent in Xylaria, Rosellinia, Kretzschmaria, and Nemania. At least six categories of apical apparatus based on shape and size can be recognized. Ascospore ornamentation as seen by SEM has been exceptionally useful and provided the basis for separating Camillea from Biscogniauxia and other xylariaceous genera.

No MeSH data available.


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Stromatal characteristics of some xylariaceous fungi. A.Daldinia eschscholzii (SUT 039) B.Biscogniauxiacapnodes (SUT 212) C.Hypoxylon monticulosum (SUT 189). D.Rhopalostroma lekae (PK 148). Kretzschmariaclavus (PK 270). F.Annulohypoxylon bovei var. microspora (SUT 025). G.Roselliniaprocera (SUT113). H.Astrocystis mirabilis (SUT 051). I.Xylaria sp.(PK 017). J.X. cubensis (PK 108). K.X. magnoliae var. microspora (PH 072). L.X. allantoidea (PK 088). Bars A–B, I–L = 1 cm; C, F–H = 5 mm; D–E = 2 mm.
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Figure 1: Stromatal characteristics of some xylariaceous fungi. A.Daldinia eschscholzii (SUT 039) B.Biscogniauxiacapnodes (SUT 212) C.Hypoxylon monticulosum (SUT 189). D.Rhopalostroma lekae (PK 148). Kretzschmariaclavus (PK 270). F.Annulohypoxylon bovei var. microspora (SUT 025). G.Roselliniaprocera (SUT113). H.Astrocystis mirabilis (SUT 051). I.Xylaria sp.(PK 017). J.X. cubensis (PK 108). K.X. magnoliae var. microspora (PH 072). L.X. allantoidea (PK 088). Bars A–B, I–L = 1 cm; C, F–H = 5 mm; D–E = 2 mm.

Mentions: Xylariaceae is one of the best-known and widely distributed families of Ascomycota. The majority of the species are wood inhabitants, and are particularly well represented in the tropics. Ju & Rogers (1996) recognized 38 genera, Whalley (1996) 40, and the number has grown to at least 76 (Lumbsch & Huhndorf 2010), although the total varies according to individual opinion and the status of several genera in the family awaits confirmation. The separation of genera and subsequent identification of taxa has been problematic mainly as a result of diversity of form and variation in many morphological characteristics (Whalley 1996, Rogers 2000). Genera within Xylariaceae were traditionally recognized on the basis of stromal form, stromal colour, and ascospore shape and dimensions (Fig. 1). As a consequence other important taxonomic features were neglected (Rogers 1979, Whalley 1996). Details of the ascus, including the apical apparatus, and ascospore topography were not considered. The subsequent advent of scanning electron microscopy (SEM) has demonstrated the value of spore ornamentation and details of stromatal surfaces (Læssøe et al. 1989, Whalley 1996). In this paper we assess the importance of these characteristics based on our experience and extrapolations from recent publications.


Ascus apical apparatus and ascospore characters in Xylariaceae.

Suwannasai N, Whalley MA, Whalley AJ, Thienhirun S, Sihanonth P - IMA Fungus (2012)

Stromatal characteristics of some xylariaceous fungi. A.Daldinia eschscholzii (SUT 039) B.Biscogniauxiacapnodes (SUT 212) C.Hypoxylon monticulosum (SUT 189). D.Rhopalostroma lekae (PK 148). Kretzschmariaclavus (PK 270). F.Annulohypoxylon bovei var. microspora (SUT 025). G.Roselliniaprocera (SUT113). H.Astrocystis mirabilis (SUT 051). I.Xylaria sp.(PK 017). J.X. cubensis (PK 108). K.X. magnoliae var. microspora (PH 072). L.X. allantoidea (PK 088). Bars A–B, I–L = 1 cm; C, F–H = 5 mm; D–E = 2 mm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3539315&req=5

Figure 1: Stromatal characteristics of some xylariaceous fungi. A.Daldinia eschscholzii (SUT 039) B.Biscogniauxiacapnodes (SUT 212) C.Hypoxylon monticulosum (SUT 189). D.Rhopalostroma lekae (PK 148). Kretzschmariaclavus (PK 270). F.Annulohypoxylon bovei var. microspora (SUT 025). G.Roselliniaprocera (SUT113). H.Astrocystis mirabilis (SUT 051). I.Xylaria sp.(PK 017). J.X. cubensis (PK 108). K.X. magnoliae var. microspora (PH 072). L.X. allantoidea (PK 088). Bars A–B, I–L = 1 cm; C, F–H = 5 mm; D–E = 2 mm.
Mentions: Xylariaceae is one of the best-known and widely distributed families of Ascomycota. The majority of the species are wood inhabitants, and are particularly well represented in the tropics. Ju & Rogers (1996) recognized 38 genera, Whalley (1996) 40, and the number has grown to at least 76 (Lumbsch & Huhndorf 2010), although the total varies according to individual opinion and the status of several genera in the family awaits confirmation. The separation of genera and subsequent identification of taxa has been problematic mainly as a result of diversity of form and variation in many morphological characteristics (Whalley 1996, Rogers 2000). Genera within Xylariaceae were traditionally recognized on the basis of stromal form, stromal colour, and ascospore shape and dimensions (Fig. 1). As a consequence other important taxonomic features were neglected (Rogers 1979, Whalley 1996). Details of the ascus, including the apical apparatus, and ascospore topography were not considered. The subsequent advent of scanning electron microscopy (SEM) has demonstrated the value of spore ornamentation and details of stromatal surfaces (Læssøe et al. 1989, Whalley 1996). In this paper we assess the importance of these characteristics based on our experience and extrapolations from recent publications.

Bottom Line: Camillea is for example, instantly recognizable by its rhomboid or diamond shaped apical apparatus, and the distinctive inverted hat or urniform type is usually prominent in Xylaria, Rosellinia, Kretzschmaria, and Nemania.At least six categories of apical apparatus based on shape and size can be recognized.Ascospore ornamentation as seen by SEM has been exceptionally useful and provided the basis for separating Camillea from Biscogniauxia and other xylariaceous genera.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology (Microbiology), Faculty of Science, Srinakharinwirot University, 114 Sukhumvit 23, Bangkok, 10110, Thailand;

ABSTRACT
Members of Xylariaceae (Ascomycota) are recognized and classified mainly on the morphological features of their sexual state. In a number of genera high morphological variation of stromatal characters has made confident recognition of generic and specific boundaries difficult. There are, however, a range of microscopical characteristics which can in most cases make distinctions, especially at generic level, even in the absence of molecular data. These include details of the apical apparatus in the ascus (e.g. disc-shaped, inverted hat-shaped, rhomboid, composed of rings, amyloid, non-amyloid); position and length of the germ slit; and presence and type of ascospore wall ornamentation as seen by scanning electron microscopy (SEM). Unfortunately many of the classical studies on xylariaceous genera omitted these features and were undertaken long before the development of scanning electron microscopy. More recent studies have, however, demonstrated their value as diagnostic characters in the family. Camillea is for example, instantly recognizable by its rhomboid or diamond shaped apical apparatus, and the distinctive inverted hat or urniform type is usually prominent in Xylaria, Rosellinia, Kretzschmaria, and Nemania. At least six categories of apical apparatus based on shape and size can be recognized. Ascospore ornamentation as seen by SEM has been exceptionally useful and provided the basis for separating Camillea from Biscogniauxia and other xylariaceous genera.

No MeSH data available.


Related in: MedlinePlus