Occurrence of Entorrhiza scirpicola (Ustilaginales) on Eleocharis quinqueflora in Britain

Notes and brief articles Table

2.

499

Dimensions of Mycosphaerella spp. described from citrus

Ascospore

Ascus Source M. horii, Japan (Yamada, 1956) M. citri, Florida (Whiteside, 1972) Mycosphaerella sp., N.S.W,

*

Ascocarp diameter (pm)

58-9 0

,----'--------,

Length (pm)

Width (pm)

Length (pm)

Width (pm)

48'3 (29'3-58'5)*

5'8 (2'7- 10'6)

12'0 (7'9- 1 5'9)

25-35

5'0-5'5

2'9 (2'3-3'7) 2'5 (2'2-2'8)

8'5

(6'2-11'2)

80-85 (65-110)

5'0-6'5

to'5 (8'0-12'5)

2'5 (2'5-3'0)

Bracketed figures indicate the upper and lower limits of the dimensions.

I wish to thank Prof. B. J. Deverall, University of Sydney, for advice. I also thank colleagues of the Biological and Chemical Research Institute, Rydalmere for encouragement and editorial assistance. The excellent technical support of Ms. C. Nuzum is also gratefully acknowledged. REFERENCES

FISHER, F, E, (1961). Greasy spot and tar spot of citrus in Florida. Phytopathology 51, 297-303. JONES, D. R. & DEVERALL, B. J. (1977). The effect of the Lr20 resistance gene in wheat on the development of wheat rust, Puccinia recondita. Physiological Plant Pathology 10, 275-284. TANAKA, S. & YAMADA, S. (1952). Studies on the greasy spot (black melanose) of citrus. I. Confirmation of the causal fungus and its taxonomic study. TokaiKinki Agricultural Experiment Station, Horticulture Division Bulletin 1, 1-15.

WELLINGS, C. R. (1978). Greasy spot of citrus in N.S.W. Agricultural Gazette of N.S.W. 89,40-41. WELLINGS, C. R. & EMMETT, R. W. (1978). Greasy spot of citrus. Proceedings International Society Citriculture 1978, 192-197. WHITESIDE, J. O. (1970). Etiology and epidemiology of citrus greasy spot. Phytopathology 60, 1409-1414. WHITESIDE, J. O. (1972). Histopathology of citrus greasy spot and identification of the causal fungus. Phytopathology 62, 260-263. WHITESIDE, J. O. (1977). Behaviour and control of greasy spot in Florida citrus groves. Proceedings International Society of Citriculture 3, 981-986. YAMADA, S. (1956), Studies on the greasy spot (black me1anose) of citrus. II. Morphological characters of the causal fungus (Mycosphaerella horii Hara), Tokai-Kinki Agricultural Experiment Station, Horticulture Bulletin 3, 49-64.

OCCURRENCE OF ENTORRHIZA SCIRPICOLA (USTILAGINALES) ON ELEOCHARIS QUINQUEFLORA IN BRITAIN SHEILA S. HOOPER AND B. M. SPOONER

The Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE

Three recent collections from Perthshire have confirmed the presence of Entorrhiza scirpicola (Correns) Sacco & Syd. in Britain. The subsequent discovery of a further collection on herbarium material of Eleocharis quinquefiora from Norfolk is also reported. These collections are described and the geographical distribution of the species briefly discussed. Species of the genus Entorrhiza C. Weber are characterized by their formation of galls on the roots of Cyperaceae and Juncaceae, and the production of single, thick-walled teliospores which Trans. Br, mycol, Soc. 76 (3), (1981).

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are permanently embedded within the host root cells. The genus holds an isolated position in the U stilaginaceae. Five species are recognized by Fineran (1978 b) in her revision of the genus, all typically European. The species are distinguished largely on spore characters, supplemented by structure and form of the sorus. Two species occur on Juncus and both have been reported from the British Isles. Ainsworth & Sampson (1950) recorded E. aschersoniana (Magnus) Lagerh. on the basis of an old collection by Trail onJ. bufonius from Aberdeen, which they

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N otes and brief articles

had not seen. That collection has, however, been examined by Fineran, and a more recent collection at Kew on the same host, reported by Dennis (1971), is also referable to thi s species. Dennis also reports a collection from West Ross on roots of]. articulatuswhich, having more globose spores, has been referred to E. digitata Lagerh., reduced by Fineran to synonymy under E. caspary ana (Magnus) Lagerh. None of the three cypericolous species has been previously reported from Britain. Recently, however, when collecting and wash ing roots of Eleocharis quinqueflora (F. X. Hartmann) Schwartz (=Scirpus pauciflorus Lightfoot), for biochemical study, in three adjacent localities in Perth, Scotland, one of us (S.S.H.) noticed the presence of unusual whitish swellings on the slender fibrous roots of a small percentage of the plants collected. These swellings could at first be confused with buds, sometimes of the same size, terminating the slender rhizomes, by means of which the plant pioneers new stem clusters. They were collected for further examination. Although no proper quantitative assessment was made, a visual impression was obtained that the occurrence of swellings on roots of plants growing along a wet ride in a deciduous plantation, on a hillside above Queen's View, where the soil appeared to be waterlogged micaceous silt, was more frequent than in the case of plants from two nearby localities in the Glen Shee area where the plants were rooted largely in peat. The collected plants were sub sequently examined at the jodrell Laboratory, Kew, where thin sectioning revealed the presence of fungal spores in cells of the swollen roots. The material is in good condition, with numerous apparently mature spores present, and is undoubtedly referable to E. scirpicola. A subsequent examination of Kew herbarium material of Eleocharis quinquefiora has revealed one further locality for this fungus. The following description is based on British material. ENToRRHIzA SCIRPICOLA (Correns) Sacco& Sydow in Sacc., Syll. fungo 14: 425 (1899) (Figs 1-2). Schinzia scirpicola Correns, Hedwigia 36: 38-40 (1897)· Sori in roots, forming cylindrical to fusoid swellings 0'8-3 mm diam, 4-20 mm long, simple or rarely bifid, smooth, whitish with a few brown to blackish marks, conspicuous in the root system, a few to many such developments per plant. Teliospores 13-16'5 x 9-13 Jlm, embedded in and frequently filling the swollen host cells with up to about 40 spores per cell as seen in a squash mount, Trans . Br. mycol. Soc. 76 (3), (1981).

thick-walled, ellipsoid to broadly ellipsoid, at first hyaline, becoming yellowish brown to pale purplish brown when mature, the intensity of the pigment varying greatly, ornamented with raised, obliquely disposed and irregularly spiral lines 0'5-1 pm wide, 1-2 Jlm high, rarely anastomosing or branching. Intracellular hyphae sparse. Specimens examined: In roots of Eleocharis quinquefl ora, track with water runnel, in deciduous woodland, on lower slopes of Meal na'h lolaire, 350 m alt., above Queen's View, Loch Tummel, Perthshire, 23 July 1979, Hooper & Townsend 1724; in deep wet peat 550 m alt., below Devils' Elbow, Gleann Beag, Perthshire, 23 July 1979, Hooper & Townsend 1725; on peaty basic flushes, 700 m alt., W side of Creagon Bheithe, Glen Shee, Perthshire, 24 July 1979, Heoper & Townsend 1726; swamp near Thurne, East Norfolk, 29 June 1915, C. E. Salmon.

Normal roots of the host are grey-brown in colour when mature and about 0'3 mm diam, so that galled roots, being swollen and whitish, are mostly very conspicuous. Basally, at the point of branching of the original root, they are darker and of normal diameter. This creates a very narrow point of attachment and causes the swollen roots to become detached easily. The British material agrees quite closely with the type description, though it differs in possessing smaller spores . Holotype material is apparently not in existence and Fineran (1978b) has selected lectotype material in which the spores are evidently also larger, being given as (16-)18-28'5(-31 '5) x (10'0-)13 '0-20'0(-23'5) utn. Ferdinandsen & Winge (1914) state, however, that young spores in material from the Faeroes measure 15 x 9 Jlm, and apparently they were unable to find any larger. That measurement agrees well with the British material, and it may be that this is not fully mature. The species was described from Val Maggia, Canton Tessin, Switzerland, and the geographical distribution has been summarized by Fineran (1978 b). It should be noted, however, that this distribution includes the known range of the fungus described as E. raunkiaeriana Ferd. & Winge on Scirpus fiuitans. This was described as differing from E. scirpicola in longer and more narrowly ellipsoid spores and in the shape of the galls, but has been placed in synonymy by Fineran. This species is stated by Liro (1938) and Zundel (1953) to occur in England, but no collections are cited. Ainsworth & Sampson (1950) do not record it as British, and Fineran (1978 b) suggests these records are based on a misinterpretation of inform ation. Similarly, the distribution

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B

Fig. 1. Entorrhiza scirpicola. (A) Habit sketch of galled roots, Hooper & Townsend 1726 (x 3); (B) habit sketch with bifid gall, C. E. Salmon, 29 June 1915 (x 5); (C) teliospores, Hooper & Townsend 1724 (x 1200).

includes New Zealand collections of a fungus in roots of Scirpus basilaris, S. cernuus and S. setaceus. It is worth noting that the spores in all these collections have been described by Fineran as differing from European material in having the ridges parallel to the long axis of the spore, rather than obliquely orientated. This is clearly shown in her electron micrograph studies (Fineran, Trans. Br. mycol. Soc. 76 (3), (1981).

1978a). It is also worth noting that although two of these host species, S. cernuus and S. setaceus, are widespread in Europe, no root galls have yet been recorded from them. In view of the hypogeous habit of these fungi and the ease with which swollen roots become detached, they are likely to have been overlooked in many areas. Careful collection of known host species from throughout

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Notes and briefarticles

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Fig . 2. Galled root s of Eleocharis quinquefi ora, Hooper & Townsend 1726 ( x 5).

their range should prove worthwhile . The relationship between occurrence and soil conditions might also prove interesting. With regard to swellings on roots of Cyperaceae, attention is also drawn to observations by Davies, Briarty & Rieley (1973) on the presence of swellings with a non-fungal origin in some species. Superficially these may closely resemble the galls, and similarly are easily detached. They are, however, hairy and show no fungal spores when sectioned. The cause of their development appears to the authors to be physiological, in response to environmental conditions. REFERENCES AINSWORTH, G. C. & SAMPSON, K . (1950). Th e British Smut Fungi ( Ustilaginales). Commonwealth Mycological Institute, Kew. Tran s. Br, my col, Soc. 76 (3), (1981).

DAVIES, J., BRIARTY, L. G. & RIELEY, J. O. (1973). Observations on the swollen lateral roots of the Cyperaceae. New Phytologist 72, 167-174. DENNIS, R. W. G. (1971). New or interesting British microfungi. Kew Bulletin 25, 335-374. FERDINANDSEN, C. & WINGE, O. (1914). Studies in the genus Ent orrhiza C. Weber. Dansk Botanisk Arkiv 2, 1-14. FINERAN, J. M . (1978a ). A scanning electron microscope study of teliospores in Entorrhiza C . Weber (Ustilaginales). No va Hedwigia 29, 825-845. FINERAN, J. M . ( 1978 b). A taxonomic revision of the genus Entorrhiza C. Weber (Ustilaginales). Nova H edwigia 30, 1-68. LIRO, ].1. (1938). Die Ustilagineen Finnlands 2. Annales A cademiae S cientiarum Fennicae A 42 (I), 1-7 2 0 . ZUNDEL, G . L. (1953). The Ustilaginales of the World. Pennsylvanian State College, Department of Botany Contribution 176,410 pp.

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