[ 3°1 ]

Trans. Br. mycol, Soc. 56 (2), 301-3 Il1 (1971)Printed in Great Britain

NOTES AND BRIEF ARTICLES

T UNICOPSORA , A NEW RUST GENUS ON BAMBOO

SUJAN SIN GH AN D P. C . PANDEY

Forest Research Institute and Colleges, Dehra Dun, India

(Wi th Plat es 33-34 a nd 4 T ext-figures)

During a disease survey in New Forest, Dehra Dun, Uttar PradeshState, a twig blight of bam boo (Dendrocalamusstrictus Nees) was collected. Thedisease was caused by a rust which att acked th e leaf sheaths, resulting indeath ofleaves and twigs above the region of infection. Such infected twigsstood out distinctly in the clumps. T he rust did not compare with anyknown genus of plan t rusts and is th erefore describ ed in a new genus.

Tunicopsora gen .nov. closely resem bles Dasturella but differs from it in th echaracters described in T able I.

T able I. Generic characteristics cifDastu rella and Tunicopsora

Dasturella

Uredia paraphysate

Telia and ured ia on leav es

Telia har d , knob-like cushions

Teliospores firmly united both lat erallyand terminally

T ermina l teliospores with much thi ckerouter wa lls

Germ pores in teliospores not observed

Tunicopsora

Uredia apar aphysate

Telia and ur edia on leaf sheaths

T elia in long blac k sheaths whi ch may behard during dry season but become softand develop in concen tri c rings a roundleaf sheaths during ra iny seaso n

T eliospores no t firmly united

Ap ices of teliospores equally thi ck in allspo res

T wo distin ct germ pores in each teliospore

Tunicopsora gen.nov.Uredosori epidermide teeti, eru mpen tes, lineares, aparaphysatae, ad foliorum vaginas;

uredosporac sessiles, sub glob osae, ovoideae vel pyriformes, sparse eehinulat ae. Teliosoriin vag in is p lanis atris ; texturae sporogenae ad hyphas laxe eontiguas dispositae ; eatenaeteliosporarum nee lat eral iter nee vertical iter adhaeren tes; tcliosporae pallide brunneaevel brunneae, un icellulares, poris germinativis duobus instruetae; promycelium extern um,e cellulis 4 compositum . Pyenosori et aeeiosori non observati.

A Dasturella differt uredosoris aparaphysat is, telio sororum vaginis planis a tris, etteliosporis non adhaerentibus poris germinativis duobus instruetis.

Spe cies typiea : Tunicopsora bagchii.

Uredia on leaf sheaths, subepidermal, erumpent, linear, ap araphysate;uredospores sessile, subglobose, ovoid to pyriform sparsely echinulate.Telia in flat , black sheaths, sporogenous tissues on pseudoparenchymatoushyphal layer with radiating black hyphae in th e lower region, teliospore

19-2

302 Transactions British Mycological Societychains not laterally or vertically adherent, teliospores light brown tobrown, single celled, with two germ pores; promycelium external, four­celled . Pycnia and aecia not observed.

Close to Dasturella, from which it differs in having aparaphysate uredia,flat telial sheaths and non-adherent teliospores with two germ pores. InDasturella, uredia are paraphysate and telia are hard, knob-like cushions;teliospores are firmly united laterally and terminally, the terminal sporeswith much thicker walls; germ pores are not observed (Cummins, 1959).

Tunicopsora bagchii sp.nov.

Uredosori epiphylli, multiseriati, epidermide teeti, erumpentes, aparaphysati, lineares,usque 3 rom longi, 80-2 IOI"m lati. Uredosporae 25-45 x 20-34 pm, sessiles,subglobosae,ovoideae vel pyriformes, sparse eehinulatae, crassitunicatae (tunica usque 1-2 pmerassa), eellulis basalibus aurantiacis gestae. Teliosori in gregibus eompluribus admarginem uredosororum orti, serius in vaginis planis atris expansis exorti, demumplerumque 2-3 em prominentes; texturae sporogenae ad hyphas laxe eonfertas ramosasseptatas erassitunieates ereseentes; eatenae teliosporarum nee lateraliter nee vertiealiteradhaerentes. Teliosporae 30-50 x 15-19 pm oblongae, obovoideae vel eIlipsoideae,reetangulares, unieellulares, pallide brunneae vel brunneae, poris germinativis duobuslatero-apiealibus, tunica usque 1'2-2 pm erassa ad apieem crassiore ; promyceliumexternum, e cellulis 4 compositum. Basidiosporae globosae vel subglobosae, hyalinae velf1avidae. Pyenosori et aeciosori non observati.

Ad foliorum vaginas Dendrocalami stricti Nees, New Forest, Dehra Dun, Uttar Pradesh.DD herb. 8092, typus; isotypus in Herb. K.

Uredia first noticed in September, continue to appear until Augustthe following year, on upper surface of leaf sheaths (PI. 33, figs. I, 2),orange-yellow, subepidermal (deep-seated in the cortex), later erumpentby rupturing the epidermis (PI. 33, fig. 3), linear, in many rows all overthe sheath, extending up to the base of leaf petioles, up to 3 mm long,80-2 10 pm broad, old sori usually attacked by contaminants; uredosporesorange-yellow, sessile, borne on orange-yellow basal cells, subglobose,ovoid to pyriform, sparsely echinulate, 25-48 x 20-34 utn, wall 1-2 pmthick.

Telia first appear during September within uredia, continuing todevelop along with uredosori, appearing in groups at the periphery ofuredia (PI. 33, fig. 3) from September to June the following year, whenthey are irregular in shape and both transversely and vertically septate(PI. 33, fig. 4). They begin to develop in a continuous and concentricblack sheath all along the length of the leaf sheaths (PI. 33, fig. I) duringmonsoons in July and August. Professor G. B. Cummins, Botany and PlantPathology Department, Purdue University, Indiana (U .S.A.), to whomthe rust was referred, remarked that the difference in development ofteliospores may be due simply to a pressure difference.

Tclial sheaths composed of loosely packed, septate, thin- to slightlythick-walled, radiating hyphae in the lower portion, above which is azone of prostrate, intertwined hyphae forming a pseudoparenchymatouslayer. Sporogenous tissue bearing teliospore chains is borne on the pseudo­parenchymatous layer, teliospore chains borne on basal cells, loosely

Trans. Br, mycol. Soc. 56 (2), (1971). Printed in Great Britain

Trans. Br. mycol, Soc. Vol. 56. Plate 33

(Facingp. 303)

Notes and Brief Articles

lat erall y appressed with one another at first, sepa rating on germination(PI. 33, fig. 5) ; teliospores loosely placed in chain s, light brown to brown,single celled, rectangular, ovoid, obovoid to sometimes elliptical or oblong,30-50 x 15-19 pm, wall brown, 1'2-2" 0 pm thick, mostly thicker at theapices, germ pores two in each spore, one on either side near th e apex, inapical spores germ pores are at the base and side of the thickened apex;promycelium external (T ext-fig. I), 4-celled; basidiospores globose tosubglobose, hyaline to yellowish.

Text-fig. 1 . Tunicopsora bagchii. Germinating teliospores. x 800.

Sincere thanks are due to Professor G. B. Cummins for his invaluableadvice and for suggesting the name of the new genus and to Messrs D. N.Pegler and A. K. Airey Shaw, Royal Botanic Gardens, Kew, for renderingthe Latin diagnoses. Grateful acknowledgement is made to Dr B. K.Bakshi, Forest Pathologist, of this Institute for guidance in the work.

R EFERENCE

Cu~nuxs, G. B. (1959) . Illustrated genera !if rust fung i. Minneapoli s, Minnesota : BurgessPublishing Co.

EXPLANATION OF PLATE 33Tunicopsora bagchii

Fig. I. Leaf sheath of Dendrocalamus strictus, showing uredia, and black telial sheaths projectingfrom leaf sheaths. x 0·6 .

Fig. 2. U redia on leaf shea th . x 4 0.

Fig. 3. Section th rough uredial sorus, showing uredospores with teliospores develop ing on th eperiphery. x J40.

Fig . 4. An enlarged view of teliospores, showing trans verse and vert ical septations. x 500.

Fig. 5. A telial sorus with chains of gennina ting teliospores borne on sporoge nous tissues. Chainsseparating from one another on germina tion. x 230.

Trans. Br. mycol. Soc. 56 (2), ( [971). Printedin Great Britain