Microsoft Word - 10. A NEW NITELLA Ag.doc Bangladesh J. Plant Taxon. 21(2): 181-185, 2014 (December) © 2014 Bangladesh Association of Plant Taxonomists NITELLA ZAMANII SP. NOV. (CHAROPHYTA) FROM BANGLADESH NASRIN JAHAN DIBA, SABRINA NAZ1 AND HENDRIK SCHUBERT2 Department of Botany, University of Rajshahi, Rajshahi-6205, Bangladesh Keywords: New species; Nitella zamanii; Characeae; Bangladesh. Abstract Nitella zamanii has been described and illustrated as a new species from a rice field at Charghat upazila in Bangladesh. The new species resembles Nitella furcata and N. polycarpa but differs by presence of accessory branchlets, spiky dactyls and size of oogonium, oospore and antheridium. Introduction Nitella Ag. had been described by different researchers (Islam and Sarma, 1976; Aziz and Tanbir, 2003; Islam and Irfanullah, 2005; Aziz, 2009; Naz et al., 2009; Diba and Naz, 2011) from different parts of Bangladesh and morphologically described with their habitats. A new species of Nitella is presented in this paper with illustration. This Nitella species was collected from a rice field at Rajshahi district in Bangladesh. A total of seventeen taxa of Nitella have been so far reported from Bangladesh (Naz et al., 2011). Specimens were collected from only one location and 10 cm depth of water by hand and preserved in Transeau`s solution (Transeau, 1916). Class: Charophyceae; Order: Charales; Family: Characeae; Genus: Nitella Ag. Nitella zamanii Naz, Diba & Schubert, sp. nov. (Figs 1-14; Pl. 1). Diagnosis: Nitella zamnii is closely related to N. furcata and N. polycarpa but differs from them by presence of accessory branchlets, spiky dactyls, size and position of gametangia, size of oogonium and oospore, and rare occurrence of antheridium. Type: Bangladesh, Rajshahi district, Charghat, Chamta beel, rice field, growing on soft mud, 10 cm of water depth, 4 January 2004, Nasrin Jahan Diba N16 (Holotype: PLLBDRB). Plant monoecious, height 5-6 cm, spiky in appearance, mucus absent, slightly encrusted; lower whorls slightly spreading, stem 250 µm in diameter; internodes 1-2 cm, branchlets 5-8, 172 µm in diameter, height 1-2 cm; furcation irregular; branchlet two types: short accessory branchlet and long branchlets; accessory branchlet few, sometimes curved, primaries 3, of which one is not furcate, two rays again forked into 1 or 2, secondaries two, unequal; dactyls 2-celled, acute; a long unbranched branchlet arise from the base of a whorl and primaries 2-celled, dactyls 2 or 3, unequal, short, acute; long branchlet 1-3 times furcate, primaries 1/3 of the total branchlet, 4-6 in number, forked into 3, 4, 6 secondaries, few are again forked into 3 or 4 tertiaries; dactyls 1-4, different types, abbreviated, spine like, spreading, tapering, 1 or 2 celled, penultimate cell tapering distally to base of end cell, sometimes acuminate, ultimate cell acute; gametangia conjoined; 1Corresponding author: Email: drsabrina_naz@yahoo.com 2Institute of Bioscience, University of Rostock, Albert-Einstein-Str. 3, D-18059, Rostock, Germany 182 DIBA et al. Figs 1-14. Nitella zamanii Naz, Diba & Schubert, sp. nov. 1. Habit; 2. Upper portion of a plant; 3-4. A whorl; 5. Upper portion of a branchlet; 6−8. Dactyls; 9. Oogonium; 10. Oospore; 11. Oospore membrane; 12−14. Branchlet node with aggregated gametangia. (Scales: 1−4 & 11 = freehand drawing; rest = 0.2 mm) oogonium usually aggregated in all branchlet nodes and at the base of whorl; lateral, short whorl arise from all stem nodes, oogonium 63-287 µm long, 35-208 µm wide, convolutions 6-9; corona two tiers, 39-40 µm long, 40-63 µm wide at the base, upper cell elongated, acute, sometimes unequal; oospore globose, 29-198 µm long, 22-165 µm wide, with 5 prominent ridges; membrane reticulate, antheridia rare, 185 µm in diameter. NITELLA ZAMANII SP. NOV. FROM BANGLADESH 183 Habitat: Nitella zamanii was collected from a shallow water habitat. This low land was cultivated with different crops, e.g. rice, wheat and sugarcane, in different seasons. After rainy season, charophytes densely grow in this location. Water depth ranged 5-15 cm. Nitella zamanii was found associated with Nitella furcata subsp. furcata f. sieberi (A. Br.) R.D.W. Distribution: Only known from Chamta beel, Charghat Upazila, Rajshahi, Bangladesh Plate 1. Nitella zamanii Naz, Diba & Schubert sp. nov. 1. Habit; 2. Fertile branchlet; 3. Tiny, short accessory branchlet; 4. Dactyls; 5. Short curved accessory branchlet; 6. Oospore; 7. Stem node and oogonium; 8. A long and unbranched branchlet. (Scales = 0.2 mm). 184 DIBA et al. Etymology: Nitella zamanii has been named in honour of Professor M. Zaman, Department of Botany, University of Rajshahi, Bangladesh for his lifelong contribution to Phycology. Notes: The new species Nitella zamanii has unique characteristics (Table 1). The whole plant is spike like. Accessory branchlets arise from the base of whorl and 1st furcation at a branchlet; accessory branchlets are of different types, elongated, short and sometimes curved. Dactyls are spine like. Fertile specimens of N. zamanii can easily be distinguished from Nitella furcata. The gametangia of Nitella furcata are restricted to the branchlet nodes (Zaneveld, 1940; Wood and Imahori, 1965), whereas oogonia of Nitella zamanii are aggregated at the base of whorl and each branchlet nodes. Nitella zamanii is similar to Nitella polycarpa which has oogonia at the base of whorls. But it differs from Nitella polycarpa (Pal et al., 1962; Naz et al., 2009) by the presence of accessory branchlets and the whorls of N. polycarpa are diffuse but the whorls of N. zamanii are compact. It is morphologically closely related to another Nitella, i.e. Nitella furcata subsp. megacarpa f. megacarpa (Wood and Imahori, 1965). But it differs by the position of gametangia and oospore membrane, the gametangia of Nitella furcata subsp. megacarpa f. megacarpa are restricted to the branchlet nodes and oospore membrane is finely to coarsely papillate, appearing incompletely reticulate at lower focus (Wood and Imahori, 1965). Oospore membrane of Nitella zamanii is finely reticulate. Table 1. Comparison of morphological features of Nitella zamanii with closely related taxa of Nitella. Morphological features Nitella zamanii N. furcata (Zaneveld,1940) N. polycarpa (Pal et al., 1962) N. furcata subsp. megacarpa f. megacarpa (Wood and Imahori, 1965) Accessory branchlets Present Absent Absent Absent Oogonium 63-287 µm long, 35-208 µm wide 240-450 µm long, 220-320 µm wide 480 µm long, 370 µm wide 300-700 µm long, 260-510 µm wide Antheridium 185 µm 240-350 µm 275 µm 220-300 (-445) µm Oospore 29-198 µm long, 22-165 µm wide 190-300 µm long, 180-270 µm wide 260 µm long, 250 µm wide 280-420 µm long, 245-380 µm wide References Aziz, A. 2009. Genus Nitella (C. Agardh) Hooker. In: Ahmed, Z.U., Khondker, M., Begum, Z.N.T., Hasan, M.A., Kabir, S.M.H., Ahmad, M., Ahmed, A.T.A. and Rahman, A.K.A. (Eds), Encyclopedia of Flora and Fauna of Bangladesh, Vol. 4. Algae: Charophyta-Rhodophyta (Achnanthaceae-Vaucheriaceae). Asiatic Society of Bangladesh, Dhaka, pp. 15-23. Aziz, A. and Tanbir, M. 2003. Algal flora of some northern districts of Bangladesh. Bangladesh J. 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Transeau, E.N. 1916. The periodicity of fresh water algae. Amer. J. Bot. 3: 121-133. Wood, R.D. and Imahori, K. 1965. A revision of the Characeae. Part - I. Monograph of the Characeae. Verlag Von, J. Cramer, Weinheim, pp. 357-716 . Zaneveld, J.S. 1940. The Charophyta of Malaysia and adjacent countries. Blumea 4(1): 49-109. (Manuscript received on 7 July 2014; revised on 24 November 2014)