Fern Gazette

Fern Gazette

The British Pteridological Society THE FERN GAZETTE VOLUME 14 PART 5 1993 CONTENTS Page MAIN ARTICLES The chromosome number of Anogramma leptophylla (Adiantaceae: Pteridophyta) from New Zealand &. South Africa -John D. Lovis, Helga Rasbach and Tadeus Reichstein 149 Trichomanes venosum R.Br. (Hymenophyllaceae: Pteridophyta) in a Cornish garden - with a key to the Filmy-Ferns established in Britain and Ireland - F.J. Rumsey, C.A. Raine and E. Sheffield 155 Cytology of ferns from the Nilgiris. South India - V. lrudayaraj, S.S. Bir and V.S. Manickam 161 Pteridophytes of Tanzania with special reference to Pare and Usambara Mountains - R.R. Schippers Part I 171 THE FERN GAZETTEVolume 14 Part 4 was published on 4 October 1992 Published by THE BRITISH PTERIDOLOGICAL SOCIETY, c/o Department of Botany, The Natural History Museum, London SW7 5BD ISSN 0308-0838 Metloc Printers Ltd., Caxton House, Old Station Road, Loughton, Essex, IG 1 0 4PE FERN GAZ. 14(5) 1993 149 THE CHROMOSOME NUMBER OF ANOGRAMMA LEPTOPHYLLA (ADIANTACEAE: PTERIDOPHYTA) FROM NEW ZEALAND & SOUTH AFRICA JOHN D. LOVIS Dept of Plant and Microbial Sciences, University of Canterbury Christchurch, New Zealand HELGA RASBACH 23 Datscherstrasse, D-7804 Glottertal, Germany TADEUS REICHSTEIN* Inst. f. Organ. Chemie der Universitat, 19 St. Johanns-Ring CH-4056 Base!, Switzerland Key words: Anogramma, Chromosome number, Nucleolus, Aneuploidy. ABSTRACT The chromosomes of Anogramma /eptophylla (L.) Link from South Africa and from New Zealand were counted. Contrary to former reports we found n•2611 for each sample, thu. showing that the speciesi caryologically homogeneous worldwide. In A. leptophylla the nucleolus is prominent during early diakinesi in each cell as a round to oblong coloured body, larger than one chromosome. We assume that the nucleolus, together with marked differences in chromosome size, is responsible for incorrect cytological results of former workers. We interpret these chromosome size differences a connected with a Robertsonian aneuploid origin of n=261l in A. leptophy/la, relative to x = 29 in other species of Anogra mma and other genera of Adiantaceae. We have never observed B chromosomes in A. Jeptophylla. INTRODUCTION Anogra mma Jeptophylla (L.) Link (Jersey Fern) is a small fern with a worldwide distribution, well-known for its unusual short-lived, annual sporophytes. Contrary to many former publications, Mary Gibby (Manton et al. 1986:131, footnote; Gibby 1986) fo und for plants from Madeira 2611 (bivalents = regular pairs) at meiosis. This was confirmed by Rasbach & Reichstein (1990). The same number had been reported earlier by Kurita (1971:41-42) for material from Europe (without more exact localisation). More recently it has been found by Queiros et al. (1988: 124) for Portugal, by Rasbach & Reichstein (1990) for other pan of Europe (Continental Spain, France, Switzerland and Mallorca) and, most recently, for Spain by Perez Carro & Femandes Arece (1991). There is therefore little doubt that in Europe the ·pecics is caryologically homogeneous with n=2611. lt is ironic that these developments have vindicated the first European count made for this species, by Tutin, which Tutin himself came to regard as "almost certainly an error" (Fabbri 1963, 323 & 326). As pointed out by Rasbach & Reichstein (1990:345 in discussion), the plants from India (reported by Khullar in Manton et al. 1986: 130 to have n=58) may be another taxon. The same may be true for those from Mexico (Mickel et al. 1966 reported n=27 and 29). Recently we have been able to examine plants from New Zealand and from South Africa and we present here our results. From both areas the number n=29 had previously been reported (Brownlie 1958; Baroutsis & Gastony 1978), but we found the meiotic number n=2611. In the case of New Zealand, n=26 was established by two of us working apart (12,000 miles!) independently. Po sible reas ns for the previously published incorrect counts will be given in the discussion. *Author to whom requests for reprints should be sent. 150 FERN GAZETIE: VOLUME 14 PART 5 (1993) METHODS Immature sporangia were fi xed in the field, transferred into 70% aqueous ethanol (as described by Rasbach & Reichstein 1990) and sent by express airmail to Base!, and examined by H. Rasbach. The standard methods (Manton 1950:293-299) for staining, squashing and making permanent preparations were followed. Final analysis of well spread cells was done with an Olympus microscope model BHS with oil immersion and attachment for phase contrast. In the case of the New Zealand collection, part of the fixation was retained in Christchurch, kept in a -20C0 deep freeze until examined by J .D.L., initially under an Olympus CH, subsequently using a Reichert Zetopan. 2.1 Material from New Zealand J.D.L. 1991/AL l. This was collected on 20.9. 1990 by J.D.L. in Bowenvale, above Victoria Park, in the Port Hills above Christchurch where Anogramma Jeptophylla is present as numerous very restricted but often dense populations on damp bare earth at the base of rocks, usually slightly overhanging. Part of the fixation was retained for study in Christchurch and the rest sent to Base! for examination (by H.R.). Quite a number of well spread cells were obtained of which two are shown in figs. 1-2. - "" ·" ··--· ·- �· � � .. .....-- / ..... / \ . .. / . ... \ I . � .... } J , • ,/ ,../ \ �·�. 2a 2b ,, .-.. ---·�·-�· . ····· 10�m l Fig. 1-2 Cytology. Spore mother cells in meiosis. a = photographs, b = explanatory diagrams. .. I and 2 J.D.L. - 1.9911AL I from New Zealand, both showing na2611. The nucleolus, a partly coloured body, is visible; round in fig. I, oblong in fig. 2. Its outline is indicated in the diagrams as a dotted line. Prep. and photos: J.D.L. (fig. 1), H.R. (fig. 2). ANOGRAMMA LEPTOPHYLLA: CHROMOSOME NUMBER 151 "';.. ,.., ....... .... , u•""'.. O•, ,• ..... ... .. ,. ' a · - ·-. / .... / ..., ./'.� . \ ... ·� \ .. .... ! ·-,, ,.. ,.:•./) , '·-..... ,··· 3a 3b --.....__,., . .... .. ..... ... ..... ..... ... ............ ... ... _.,., ·· · ...\ (/ -'� - . '\ ' � �-�· � ! .. • • ! 4a ,�� ���LJ Fig. 3-4 Cytology continuation. Spore mother cells in mei si·. a= photographs, b =explanatory diagrams. - 3 and 4 J.E.B.- 5212 from South Africa, both showing n-26 11. Prep. and phot : H.R. 2.2 Material from South Africa Mr J.E. Burrows (Lydenburg) kindly sent us the following pressed plants with mature clean spores and fixings, taken in the field, subsequently transferred to 70% aqueous ethanol. Zimbabwe, Pit structure, Nyanga National Park, 1800 m a1 t. , E. Zimbabwe 1832 BD, growing in rock cracks of a ruined village. In montane grassland scrub mosaic, rare. 17- II-1991. J. E. & S. M. Burrows 5179. Sowing in Basei8-V-1991 (TR-7369). S.A. Coromandel farm, Blueberryfall., Lydenburg, E. Transvaal, 1830 m alt. Region S.A. 2530 D. Growing on base of quartzite cliffs in spray of ea onal drip line around r ck bases. In montane grassland. 21-III-1991, J.E. & S. M. Burrows 5212. Sowing in Base! -V-1991 (TR-7370). The fixings from Zimbabwe (J.E.B. 5179) gave no countable cells but those from Transvaal contained several cells showing the meiotic number n=26n. Two of them are shown in figs. 3 and 4. 152 FERN GAZETTE: VOLUME 14 PART 5 (1993) RESULTS All the material examined shows the meiotic number n=26II. No B chromosomes or fragments were observed by either of us, but the chromosomes of Anogramma Jeptophylla are not all of equal size. In this respect, our findings agree well with those of Perez Carro & Fermindes Areces ( 1991). In most well spread cells a partly coloured body, a little larger than a chromosome, was visible. This is a nucleolus. It was previously indicated (but not mentioned) by a dotted line (Rasbach & Reichstein 1990:346 (Figs. 3.2 and 3.3). It was again observed in material from New Zealand and South Africa (Figs. 1, 2 and 3 of this article). The nucleolus is clearly visible in earlier phases of diakinesis, but disappears by late diakinesis or prometaphase, and is never seen in metaphase I cells. Metaphase cells are less suitable for counting; the clearest figures are obtained (as in most ferns) from late diakinesis but, judging from its scarcity, it seems that this phase proceeds very quickly in Anogramma. DISCUSSION There cannot be any doubt that Anogramma Jeptophylla from New Zealand and from South Africa is the same taxon as the European species; neither morphological nor caryological differences were observed. The count which the late G. Brownlie (1958) published for New Zealand is obviously incorrect. There is no supporting photograph or figure. He was a very careful worker, but never claimed to be infallible. His was the first count to be published for this species. The voucher specimen has been located (CHR 383101) and examined, and the accompanying locality information confirms that we have studied the same population*. It is noteworthy that the count is given as n=ca. 29 in his notebook (fide J.D.L.) - it is not known how the uncertainty came to be removed. The results of Baroutsis & Gastony (1978:3-6) for A. Jeptophylla from South Africa are obviously incorrect too. In figs. 8-9 they give a photograph and diagrammatic interpretation of a cell in meiosis, and state that it was the only clear meiotic count which they were able to obtain. In our opinion this photograph is by no means convincing; it shows just 25 clearly discrete bodies - the count can be extended beyond 26 only by interpreting three bodies as being composed of pairs of tightly overlapping bivalents. Taking into account the fact that the chromosomes of A. Jeptophylla differ in size, this figure is better interpreted as n=25 or 26. The authors give also in fig. 3 a mitotic count of gametophytes from Mexico which they interpret (in fig. 4) as n=29. Here again this interpretation is not convincing; the method of counting chromosomes in prothalli is known to be difficult.

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