A correlated thin-sectioning and freeze–fracturing approach was used to reveal the ultrastructure of endogenously dormant teliospores in the smut fungus Entorrhiza casparyana (Magn.) Lagerh. Conventional fixation and embedding methods yielded poor preservation of the wall and protoplasm. Successful preservation was achieved by fixing frozen and cryosectioned spores in glutaraldehyde and subsequently processing by standard procedures for transmission electron microscopy. Freeze–fracturing provided cross- and contour-fractured views of the protoplasm and the different layers of the wall. The wall is thick, consisting of three main layers: outer, middle, and inner, with the outer and inner layers further differentiated into zones. The warty zone dominates the outer layer and consists of radial protuberances (warts) with the regions between filled to varying degrees with similar wall material containing electron-transparent lamellae. The extent of differentiation of the warty zone is reflected in the surface morphology of the spores, which ranges from verrucose to almost smooth. At the base of the outer layer is an electron-translucent irregular zone. The middle and inner layers are regular in thickness around the spore, with the middle layer being the most electron dense. The inner layer is differentiated into three zones. The most distinctive is zone 2 which in freeze–fractured walls has an unique mosaic of striae. Cytochemical staining of the wall for polysaccharide material gives a positive reaction only for the warty zone. The protoplasm contains a single nucleus and is dominated by numerous spheroidal storage lipid bodies. Squeezed among the lipid bodies are organelles, believed to be microbodies, containing a granular matrix and often electron-transparent areas. These organelles failed to show catalase activity with the 3,3′-diaminobenzidine method. Occasional short profiles of endoplasmic reticulum cisternae, a few mitochondria with sparse cristae, dispersed small clusters of glycogen, and sometimes scattered ribosomes are also present in the cytoplasm. All these features are typical of dormant spores with a low metabolic activity.

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FINERAN, J. M. 1982. Teliospore germination in Entorrhiza casparyana (Ustilaginales). Can J . Bot. 60: 2903-2913.A study was made of teliospores of Entorrhiza casparyana (Magn.) Lagerh. germinating in situ in degenerating root galls of Juncus articulatus and in galls stored in liquid media at 7OC for 15 months. Teliospores germinating on agar were also examined. This is the first description of germination in this species. Teliospores germinated in situ and produced up to four aseptate promycelia each bearing up to four falcate sporidia, often distinctively looped or curved and in a terminal or subterminal position. On agar, teliospores germinated directly and formed septate branched hyphae but no sporidia. Karyokinesis occurred in the teliospores prior to germination. Division was presumed to be meiotic and to be followed by at least one mitosis. Cytokinesis followed, with up to four sectors being formed in a spore; this feature is described for the first time and appears to be unique to this genus. The mode of germination places Entorrhiza in the Tilletiaceae and also distinguishes it from Melanotaenium. The taxonomic position of the Ustilaginales is briefly discussed; the observations made so far on spore germination in E. casparyana support the retention of the Tilletiaceae in the Basidiomycetes. FINERAN, J. M. 1982. Teliospore germination in Entorrhiza casparyana (Ustilaginales). Can J . Bot. 60: 2903-2913.Les tCliospores de lYEntorrhiza casparyana ont Ct C CtudiCes pendant leur germination in situ dans des galles racinaires en dCgCnCrescence de Juncus articulatus et dans des galles entreposCes dans un milieu liquide i 7°C pendant 15 mois. Des tkliospores germant sur de la gClose ont aussi Ct C CtudiCes. Cet article constitue la premikre description de la germination chez cette espkce. Les tCliospores germent in situ et produisent jusqu'i quatre promycCliums non cloisonnCs; chaque promycClium porte, en position terminale ou subterminale, jusqu'i quatre sporidies falciformes qui sont souvent en forme de boucle ou recourbCes. Sur milieu gClosC, les tCliospores germent directement et forment des hyphes ramifiCs et cloisonnCs, mais aucune sporidie. La caryocinkse se produit dans les tCliospores avant la germination. On prisume que cette division est mCiotique et qu'elle est suivie par au moins une mitose. La cytocinkse suit etjusqu'i quatre secteurs se forment par spore; cette caractkristique est dCcrite pour la premikre fois et semble Etre unique a ce genre. Le mode de germination place le genre Entorrhiza parmi les Tellitiaceae et le distingue du genre Melanotaenium. La position taxonomique des Ustilaginales est brikvement discutCe; les observations effectuCes jusqu'i maintenant sur la germination des spores de 1'E. casparyana appuient la classification des Tilletiaceae parmi les Basidiomycktes.[Traduit par le journal]The genus Entorrhiza C. Weber (Ustilaginales) was erected by Weber (1884) to describe fungi producing root swellings, or galls, on some members of the Cyperaceae and Juncaceae. The teliospores a...

Teliospores of Entorrhiza casparyana from soil infected Juncus articulatus L. in well-drained and waterlogged soils under glasshouse conditions. After 3.5 months the maximum infection perplant was 2546 galls which weighed 1.2 g (or 18.5% of the root dry weight and 9.6% of the total dry weight of the plant). After 8.5 months the maximum infection per plant was 4267 galls which weighed 14.3 g (or 54.9% of the root dry weight and 29.7% of the total dry weight of the plant). Galls were relatively evenly distributed on the roots in well-drained soils but not in waterlogged soils. The effect on plant appearance and growth (measured on a dry weight basis after 3.5 months) was insignificant, explaining why infected plants are difficult to detect in the field.

Entorrhiza is a smut fungus which produces sori as terminal swellings in the roots of the Juncaceae and Cyperaceae. The fungus appears to have little effect on the host plant. Entorrhiza has been reported previously almost entirely from Europe. Its presence in New Zealand is the first valid record of the genus in the Southern Hemisphere. The New Zealand records are of Entorrhiza digitata Lagerh. on Juncus arficulatus L. and Juncus gregifiorus L. Johnson, and of Entorrhiza scirpicala (Correns) Sacco and Syd. on Scirpus basilaris (Hook.f.) C. B. Clarke and Scirpus cernuus Yah!. This is the first record of Juncus gregiflarus, Scirpus basi/aris, and Scirpus cernuus as host plants for En tarrhiza.