PERSOONIA

Published by the Rijksherbarium, Leiden

Volume Part 6, 4, pp. 439-443 (1972)

The Suboperculate —a review

Finn-Egil Eckblad

Botanical Museum, University of Bergen, Norway

The suboperculate nature of the asci of the is discussed,

that it does in its and further and it is concluded not exist original sense,

that the Sarcoscyphaceae is not closely related to the Sclerotiniaceae.

The question of the precise nature ofthe ascus in the Sarcoscyphaceae is important

in connection with the of the the The treatment of . family

has been established the Sarcoscyphaceae as a highranking taxon, Suboperculati,

by Le Gal (1946b, 1999), on the basis of its asci being suboperculate. Furthermore, the

Suboperculati has beenregarded as intermediatebetween the rest of the Operculati,

The , and the Inoperculati, especially the order Helotiales, and its family

Sclerotiniaceae (Le Gal, 1993). Recent views on the taxonomie position of the

Sarcoscyphaceae are given by Rifai ( 1968 ), Eckblad ( ig68 ), Arpin (ig68 ), Kim- brough (1970) and Korf (igyi).

The Suboperculati were regarded by Le Gal (1946a, b) as intermediates because

had both the beneath they operculum of the Operculati, and in addition, it, some-

ofthe of the In the the thing pore structure Inoperculati. Suboperculati pore struc-

to ture is said take the form of an apical chamberwith an internal, often incomplete

within Note this ring-like structure it. that in case the on discharge have to

travers a double hindrance, the internal ring and the circular opening, and that

the diameters of these obstacles are both smaller than the smallest diameterof the

spores. Therefore, the spores have to be forced through a double hindrance; this

seems rather improbable.

There may be other reasons for accepting the Sarcoscyphaceae as a high ranking

but what I maintain here is that the taxon, am going to suboperculate nature of their first is not in few if of asci, as described, a good reason, since, my opinion, any its members have asci that in the described Le Gal. are suboperculate way by I that if this Furthermore, am going to suggest suboperculate nature of their asci is denied, in fact very little remains to place the Sarcoscyphaceae in close phyloge- netic relationship to the Sclerotiniaceae.

The term 'suboperculate ascus' was introduced by Le Gal (1946a). Later the

same year, Le Gal (1946b) stated that the term 'paraoperculate ascus' introduced

Chadefaud the by (1946) covered same thing. The term 'suboperculate' has been accepted by everbody. (Nannfeldt. 1949, Korf, J957, Denison, 1969, Rifai, 1968,

* Paper read at the Symposium "Taxonomy of operculate Discomycetes" held at the

First International Mycological Congress, Exeter, 1971.

439 Persoonia Vol. Part 1972 440 6, 4,

Eckblad, 1968 ). Le Gal (1946a) first described the phenomenon in sulcipes

described the the while Chadefaud (1946) same phenomenon, as paraoperculate

in coccinea. In Cookeina the described ascus, sulcipes suboperculate ascus was

the by Le Gal ( 1946) as having a three layered ascus wall. Within an enlargement of

middle layer the apical chamber is formed.

In later Le Gal detailed and of a paper, (1946b) gave more descriptions drawings

the suboperculate ascus of a number of , all belonging to the family Sarcos-

this have wall cyphaceae. In paper the suboperculate ascus is stated to two layers,

and she to the Cookeina too. The wall appears now regard ascus as two-layered ascus

has been demonstrated to be two-layered also in several operculate genera not

belonging to the Sarcoscyphaceae, viz. Ascobolus and Saccobolus (van Brummelen,

I have also the double wall elec- 1967), Thelebolus (Kobayasi et al., 1967). seen on

tronmicrographs in Gyromitra esculenta (unpublished).

According to Le Gal (1946b) there are three different types of suboperculate asci in the Sarcoscyphaceae.

The first is found in number of the Pseudo- type a species now belonging to genera , , , Plectania, and Sarcoscypha.

thicker the of In all these genera the inner wall layer is said to become at top

the and the chamber this Within ascus, apical to be formed within thickening.

this chamber again is formed an internal ringlike structure which is considered to

correspond—according to Le Gal—to the internal pore canal of the ascus apex of

many inoperculate Discomycetes.

In the second of the Cookeina and group, consisting tropical genera ,

Boedijnopeziza the apical chamber is said to develop, not within the inner layer, but

between the two layers. In the case of Phillipsia at least it appears from her drawings

that the is reduced inside of the circular ring-like structure to a thickening on the

left the The third Urnula opening by operculum. group, represented only by geaster,

Chorioactis differs from the latter or more correctly, geaster, only slightly type. her the described the In paper on Discomycetes of Madagascar Le Gal (1953) also

of associated with the Sarco- suboperculate apical apparatus some genera closely scyphaceae, viz. Phaedropezia Le Gal, and Midotiopsis Henn., and of Rutstroemia

nummiformis (Pat.) Le Gal of the Sclerotiniaceae.

The hypothesis that the Sarcoscyphaceae form a taxon intermediate between the

Inoperculati and the Operculati, or more especially between the Sclerotiniaceae

and the Pezizales was in the main based on these findings.

I hasten to assure that the thickened inside of the opening of the ascus ofPhillipsia

I have also In fact this described and seen. thickening or apical pad was clearly illustrated The lid itself is also thickened the inside. by Boedijn (1953). on

If this type of apical 'apparatus' is what is generally understood by a suboper-

culate do ascus, I not deny its existence. But it should be remembered that in this

the chamber has and also the internal like case apical disappeared, ring structure within it. With its the double hindrance of the disappearance discharge vanished too. What is left is a thickening of the operculum and the opening itself. F.-E. Eckblad: The suboperculate ascus 441

Table I. CHARACTERS OF SARCOSCYPHACEAE AND SCLEROTINIACEAE COMPARED

Sarcoscyphaceae Sclerotiniaceae

mode of nutrition saprobic parasitic

substrate epixylous not epixylous, except Rutstroemia, Martinia mycelium plurinucleate plurinucleate

sclerotia or stroma not, except in Wynnea common

apothecia hairy glabrous

colour Yellow, orange, red,red, black yellowish-brownyellowish-brown paraphyses mostly plurinucleate uninucleate,uninucleate, except

except “”,"Sarcosoma", Sclerotinia tuberosa Urnula, asci long shortshort

asci cylindrical clavate asci nonamyloid amyloid asci aporhynque aporhynqueaporhynque or pleuro- rhynquerhynque

small large

one-celled ascospores one-celled mosdymostly

ascospores hyaline mostly hyaline sometimes ascospores globose, ellipsoid ellipsoid, often inaequilateral slightly inaequilateral

ascospores plurinucleate uninucleate, except Sclerotinia tuberosa 2-6

Ciboria batschiana 1-2

conidial states mostly none except common

Verticicladium Botrytis, Monilia etc.

this Furthermore, type ofopening is definetly known only from the genera Phillipsia,

and but also in the Cookeina, Boedijnopeziza, may occur monotypic genera and which both related to It in few Aurophora, are closely Phillipsia. may occur a other genera too.

Of the existence of the in the I have far suboperculate ascus original sense, so seen no corroborationin the literaturein the form ofa description, drawing or photograph based studies. there several records of asci in on personal True, are suboperculate

and Galiella Geodina new species genera, (Korf, 1957), (Denison, 1969), Aurophora (Rifai, 1968), (Paden & Tylutki, 1969), Korfiella (Pant & Tewari, 1970) and Thindia of these is there (Korf & Waraitch, 1971). In none cases, however, any

of the What features of the drawing or photograph apical apparatus. ascus are referred to by the term suboperculate, has not been described.

I have studied in detailonly few species ofthe Sarcoscyphaceae. But I have studied two of them, Pseudoplectania nigrella and , and especially the former in detail. studied for three without The asci of Pseudoplectania I have years finding Persoonia Vol. Part 442 6, 4, 1972

the slightest indication either of an apical chamber or of an internal ring. Judging

from Le Gal's drawing (1946b, Fig. 2, 2) the internal ring of Pseudoplectania nigrella

wouldbe approximately 8 microns wide and 3 microns thick, i.e. clearly visible even

coccinea the described much in a light microscope. In Sarcoscypha structure is as

all of The asci have been studied smaller, although not at a submicroscopical nature. fresh in water mounts or in various media, or stained. The result is the same.

In these two genera the suboperculate apparatus of the ascus is nonexistent. On

the basis of these results in central I feel that fresh evidence for negative two genera,

the existence of this structure is The most evidence now necessary. satisfactory would be longitudinal sections of the ascus studied in light and electron microscope.

technical This sort of evidence has not yet been produced, probably because of the

difficulties in obtaining such sections.

It is to in mind that I between of asci in the necessary keep distinguish two types Sarcoscyphaceae.

—Cookeina which the itselfand the rim of the 1. The Phillipsia type, in operculum

opening of the ascus is thickened. There is no apical chamber and there is a single hindrance the This I In this of should to spores. type accept. my opinion type ascus

not be termed suboperculate, since this would amount to a virtual redefinition of

the term considering the sence it was originally given by Le Gal (ig46a).

II. The Pseudoplectania type, where there should be both the operculate opening,

and beneath it a second hindrance, the internal ring. I do not believe that this type

exists.

On theother hand I of that the of the will, course, not deny ascus Sarcoscyphaceae

series of characters. Few of these characters found in the possesses a peculiar are asci of all species, however.

with flexuous The asci are often thick-walled and often very long and a narrowing base, which is aporhynque, according to Berthet {1949) i.e. without croziers. In

some genera the operculum and opening is oblique and thickened on the inside. In

often a few genera all asci ripen simultaneously. The spores are inaequilateral

striations which stained and often with longitudinal or traverse ridges or are not

blue similar and by cotton or dyes, are mostly plurinucleate (Berthet, 1964).

These characters together with the characters of the excipulum (see Nannfeldt,

habitat and the 1949, Le Gal, 1953, Rifai, 1968, Eckblad, 1968) the epixylous trop-

several the families ical distribution of genera certainly gives family or (Korf,

somewhat exotic 1971) a image.

I unable to that these characters to a am, however, quite see point relationship

with other of the with the Sclerotiniaceae or for that matter, any group Inoperculati.

In I have confronted number of characters of the and Table 1, a Sarcoscyphaceae of the Sclerotiniaceae. Very few of the characters are the same, mostly they are

different.

My conclusion is then—in the absence of positive evidence—that the Suboper-

culati whole do as a not possess a suboperculate apical apparatus as originally

defined, and that lacking this—there is no reason to seak a phylogenetic relationship between the Suboperculati and the Inoperculati. F.-E. The Eckblad: suboperculate ascus 443

REFERENCES

ARPIN, N. (1968). Les carotenoi'des des Discomycetes: essai chimiotaxinomique. These,

Univ. Lyon (& in Bull. mens. Soc. linn. Lyon 38 (Suppl.) ).

BERTHET, P. (1964). Essai biotaxinomique sur les Discomycetes. These, Univ. Lyon.

K. B. in In Bull. BOEDIJN, (1933). The genera Phillipsia and Cookeina Netherlands India. Jard. Buitenz. Ill hot. 13: 57-76.

A of the Ascobolus and Saccobolus BRUMMELEN, J. VAN (1967). world monograph genera (Asco-

In Persoonia mycetes, Pezizales). (Suppl.) 1.

M. Les la de la Pezize CHADEFAUD, (1946). asques para-opercules et position systematique coccinea Fries C.r. hebd. Seanc. Acad. Paris Sarcoscypha ex Jacquin. In Sci., 222: 753-755.

W. C. Central American Pezizales. A the DENISON, (1965). I. new of Sarcoscyphaceae.

In Mycologia 57: 649-656.

F.-E. The A oftheir ECKBLAD, (1968). genera of the operculate Discomycetes. re-evaluation

and In Bot. taxonomy, phylogeny nomenclature. Nytt Mag. 15: 1-191. KIMBROUGH, J. W. (1970). Current trends in the classification of Discomycetes. In Bot. Rev. 36: 91-161. KOBAYASI, Y., N. HIRATSUKA, R. P. KORF, K. TUBAKI, K. AOSHIMA, M. SONEDA, &. J.

SUGIYAMA. (1967). Mycological studies on the Alaskan Arctic. In A. Rep. Inst. Ferment.

Osaka 3: 1-138.

R. P. Two KORF, (1957). bulgarioid genera: Galiella and Plectania. Mycologia 49: 107-1 11. (1971). Nomenclatural notes. VII. Family and tribe names in the Sarcoscyphineae

and of the In Taxon (Discomycetes) a new taxonomic disposition genera. 19: 782-786. R. P. & K. S. of the In KORF, WARAITCH (1971). Thindia, a new genus Sarcoscyphineae. Mycologia 63: 98-103.

LE M. Mode de dehiscence des chez les Cookeina les GAL, (1946a). asques et Leotia, et ses

du In Seanc. Acad. Paris consequences point de vue phylogenetique. C.r. hebd. Sci.,

222: 755-757- (1946b). Les Discomycetes subopercules. In Bull. Soc. mycol. Fr. 62: 218-240. de ( I953). I-es Discomycetes Madagascar. Paris.

E. & E. E. TYLUTKI Idaho I. A of the PADEN, J. (1969). Discomycetes. new genus Sarco-

scyphaceae. In Mycologia 60: 1160-1168.

D. & P. TEWARI of In Trans. Br. PANT, C. V. (1971). Korfiella, a new genus Sarcoscyphaceae.

mycol. Soc. 54: 492-495. RIFAI, M. A. (1968). The Australasian Pezizales in the Herbarium of the Royal Botanic

Kew. K. Akad. II Gardens, In Verh. Ned. Wet., Afd. Natuurk. 58 (3): 1-295 PP-