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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.


Related in: MedlinePlus

Variation in ascospore shape and germ slits. A.Rosellinia bunodes with elongated ascospore ends (AJSW 937). B.Entoleuca mammata with broadly rounded ascospores (AJSW 803). C.Biscogniauxia nummularia with broadly rounded ascospores. (AJSW 236). D.Hypoxylon comedens with straight germ slits 2/3 length of the spore (ST 1142 RFD). E.Xylaria longipes with spiral germ slit. (AJSW 576). F.H. monticulosum with spiral germ slits (SUT 189). G.Rhopalostroma kanyae with germ slit on the dorsal side of the ascospore (IMI 368200 – isotype). H.Biscogniauxia anceps showing bicelled spores and germ slit (AJSW 1009) I.H. fuscum showing dehiscent perispore following treatment with 10 % KOH (AJSW 078). J.Kretzschmaria clavus with straight germ slit almost full length of the ascospore (PK 270). A–B, D–G scanning electron micrographs. C, H–J bright field light microscopy. Bars A–B, D, G–H = 10 μm; C, E = 2 μm; F = 1 μm; I–J = 15 μm.
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Figure 3: Variation in ascospore shape and germ slits. A.Rosellinia bunodes with elongated ascospore ends (AJSW 937). B.Entoleuca mammata with broadly rounded ascospores (AJSW 803). C.Biscogniauxia nummularia with broadly rounded ascospores. (AJSW 236). D.Hypoxylon comedens with straight germ slits 2/3 length of the spore (ST 1142 RFD). E.Xylaria longipes with spiral germ slit. (AJSW 576). F.H. monticulosum with spiral germ slits (SUT 189). G.Rhopalostroma kanyae with germ slit on the dorsal side of the ascospore (IMI 368200 – isotype). H.Biscogniauxia anceps showing bicelled spores and germ slit (AJSW 1009) I.H. fuscum showing dehiscent perispore following treatment with 10 % KOH (AJSW 078). J.Kretzschmaria clavus with straight germ slit almost full length of the ascospore (PK 270). A–B, D–G scanning electron micrographs. C, H–J bright field light microscopy. Bars A–B, D, G–H = 10 μm; C, E = 2 μm; F = 1 μm; I–J = 15 μm.


Ascus apical apparatus and ascospore characters in Xylariaceae.

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

Variation in ascospore shape and germ slits. A.Rosellinia bunodes with elongated ascospore ends (AJSW 937). B.Entoleuca mammata with broadly rounded ascospores (AJSW 803). C.Biscogniauxia nummularia with broadly rounded ascospores. (AJSW 236). D.Hypoxylon comedens with straight germ slits 2/3 length of the spore (ST 1142 RFD). E.Xylaria longipes with spiral germ slit. (AJSW 576). F.H. monticulosum with spiral germ slits (SUT 189). G.Rhopalostroma kanyae with germ slit on the dorsal side of the ascospore (IMI 368200 – isotype). H.Biscogniauxia anceps showing bicelled spores and germ slit (AJSW 1009) I.H. fuscum showing dehiscent perispore following treatment with 10 % KOH (AJSW 078). J.Kretzschmaria clavus with straight germ slit almost full length of the ascospore (PK 270). A–B, D–G scanning electron micrographs. C, H–J bright field light microscopy. Bars A–B, D, G–H = 10 μm; C, E = 2 μm; F = 1 μm; I–J = 15 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Variation in ascospore shape and germ slits. A.Rosellinia bunodes with elongated ascospore ends (AJSW 937). B.Entoleuca mammata with broadly rounded ascospores (AJSW 803). C.Biscogniauxia nummularia with broadly rounded ascospores. (AJSW 236). D.Hypoxylon comedens with straight germ slits 2/3 length of the spore (ST 1142 RFD). E.Xylaria longipes with spiral germ slit. (AJSW 576). F.H. monticulosum with spiral germ slits (SUT 189). G.Rhopalostroma kanyae with germ slit on the dorsal side of the ascospore (IMI 368200 – isotype). H.Biscogniauxia anceps showing bicelled spores and germ slit (AJSW 1009) I.H. fuscum showing dehiscent perispore following treatment with 10 % KOH (AJSW 078). J.Kretzschmaria clavus with straight germ slit almost full length of the ascospore (PK 270). A–B, D–G scanning electron micrographs. C, H–J bright field light microscopy. Bars A–B, D, G–H = 10 μm; C, E = 2 μm; F = 1 μm; I–J = 15 μm.
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