Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2008
Volume 11
Issue 4
Topic:
Biology
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Grzesiuk A. , Marciniuk J. , Marciniuk P. 2008. CHROMOSOMAL DIVERSITY AMONG POLISH ORIGIN SPECIES OF TARAXACUM GENUS, EJPAU 11(4), #14.
Available Online: http://www.ejpau.media.pl/volume11/issue4/art-14.html

CHROMOSOMAL DIVERSITY AMONG POLISH ORIGIN SPECIES OF TARAXACUM GENUS

Anna Grzesiuk1, Jolanta Marciniuk2, Paweł Marciniuk2
1 Department of Plant Physiology and Genetics, University of Podlasie, Poland
2 Department of Botany, Institute of Biology, University of Podlasie, Siedlce, Poland

 

ABSTRACT

Results of research concerning the numbers of chromosomes in ten species of Taraxacum genus from area of Poland have been presented in the paper. Among studied species origin six of them was from Ruderalia section, two from Palustria section, one from Borea section and one from Erythrosperma section. For T. freticola H. Øllg., described in year 2006, two numbers of chromosomes was found: triploidal number 2n = 24 and diploidal number 2n = 16. According to our knowledge it is first information on numbers of chromosomes in this species. Similarly in case of T. hepaticum and T. melanostigma (in all these species 2n = 24) earlier data and reference had not been found and it is probably the first data ever reported, concerning the numbers of chromosomes in these species of Taraxacum genus. For the first time the number of chromosomes for narrowly apprehended T. scanicum s. str. 2n = 24 has been reported, earlier data concerned widely apprehended T. scanicum s.l. enclosing a group of related species. For T. paucilobum new number of chromosomes has been reported 2n = 26. For four species (T. copidophyllum 2n = 24, T. haematicum 2n = 24, T. hemicyclum 2n = 24 and T. sinuatum 2n = 24) it is the first time that data concerning the number of chromosomes from area of Poland have been reported. The number of chromosome for tetraploidal T. vindobonense 2n = 32 has been confirmed.

Key words: chromosome numbers, Taraxacum, Asteraceae, Poland.

INTRODUCTION

Taraxacum genus is represented by over 2000 species, belonging to nearly 50 sections [12,14,38]. In Poland over 370 species from 13 sections had been reported [7,17]. This diversity is due to sophisticated range of not identified various evolutionary processes, which resulted in numerous poliploidal forms, of mainly crossbreeded origin, that were petrified with apomictic way of reproduction [11,21,40]. Processes of hybridisation proceed particularly intensively in areas of occurrences of mixed populations, consisting of sexual diploids and apomictic poliploids. Biggest diversity of dandelions, with primitive diploidal species and filogenetically younger apomictic poliploids, occur in the area of central Asia and southern Europe [11]. The farther to the North of continents, the smaller number of diploid species occur [3,9]. In the area of Poland a young, quaternary flora almost exclusively occur. In case of dandelions such situation caused the minimum share of diploidal species,  and only one species is recognised as the Tertiary relic – Taraxacum pieninicum Pawł., the other i.e.: Taraxacum bessarabicum (Hornem.) Hand.-Mazz. and T. erythrospermum Andrz. ex Besser are well-known from single, probably anthropogenic locations. Some species of dandelions are found in a split ploidal level e.g. T. laciniosifrons Dahlt. ex Wiinstedt 2n = 24, 25, 38, 48 [35]. Phenomenon of appearing of apomictic species on different ploidal levels was also observed in some other genus, like Achillea [1], Artemisia [16] and Hieracium [37].

At present, information from Poland on the number of chromosomes comprises c. 30 taxa of the genus Taraxacum [15,20,21,22,23,24,26,27,28]. Unfortunately, many of these data pertain to some undefined species which is the effect of erroneous determinations of e.g. T. balticiforme Dahlst., T. albanicum Soest, T. apiculatum Soest, T. crassiceps Haglund ex Soest – these species according to Kirschner and Štĕpánek [13] do not exist in Poland. Another reason might be too broad understanding of some species. For example, T. scanicum Dahlst. has recently been divided into several new species [34,39] and now nobody knows to which of them refer earlier data reporting of 2n = 25 [21,22] and 2n = 24 [2]. Therefore, we have certain data on the number of chromosomes for only 14 species in Poland. These species include: T. nigricans (Kit.) Rchb. 2n = 32 [18,20], T. ostenfeldii Raunk. emend Raunk. 2n = 24 [27 as T. duplidens Lindberg], T. pieninicum Pawłowski 2n = 16 [18,19,20], T. brachyglossum Dahlstedt 2n = 24 [22], T. canophyllum Soest 2n = 16 [28], T. lacistophyllum Dahlstedt 2n = 25 [22] T. laetum Dahlstedt 2n = 24 [22], T. tenuilobum Dahlstedt 2n = 25 [22], T. paucilobum Hudziok 2n = 24 [23,24,25 as T. austrinum Haglund], T. polonicum Małecka & Soest 2n = 24 [24,25,26], T. skalinskanum Małecka & Soest 2n = 40 [24,25], T. vindobonense Soest 2n = 32 [24,25,26], T. turfosum (C. H. Schulz) Soest 2n = 24 [24,26 as T. vollmannii Soest], and T. alatum Lindberg 2n = 24 [15, 27].

This poor karyologic recognition of Polish dandelion flora inclined us to undertake long term studies aimed at determining the number of chromosomes in most Polish species of the genus Taraxacum and at creating a map of cytotypes. In this paper we determine the number of chromosomes in 10 dandelion species from three sections.

MATERIALS AND METHODS

Plant material,  used for examinations, came from the area of Poland. In each case recognition of the species was confirmed by the specialist. The location of the population was given in Table 1. For cytological study, young root tips were collected from seeds germinated on wet filter paper in Petri dishes at room temperature, when they reached 1–1.5 cm in length. Root tips were collected in the morning. The material was pretreated in 0.002 M 8-hydroxyquinoline for 4 h at 16°C, fixed in solution of ethanol acetic acid (3 : 1) overnight at room temperature and stored at 4°C in 70% ethanol until used. Root tips were hydrolyzed in 1N HCl for 12 min at 60°C and stained by the Feulgen method [6]. Then the meristem was isolated and squashed in a drop of 1% acetic carmine solution. Metaphase plates were examined with a Nikon Eclipse light microscope under oil immersion (x100). From each species/population, at least ten root tips and around 100 metaphases were analyzed to determine the chromosome number and photographs of several metaphase plates were taken.

Table 1. Origin of plants population
Taxon Section Locality

T. copidophyllum Dahlst.

Ruderalia

Bużka, meadow in Sarenka river valley, 2.05.2004, leg. J. and P. Marciniuk, det. B. Trávníček;
Trzebaw, Wielkopolska National Park, leg. et det. Z. Głowacki 2002, conf. H. Øllgaard;
Liż, Wielkopolska National Park, leg. A. Czarna 2003, det. H. Øllgaard

T. freticola H. Øllg.

Ruderalia

Bystra near Bielsko Biała, meadow at brook, 7.05.2005, leg. J. Marciniuk, det. B. Trávníček;
Skoczów, meadow, 8.05.2005, leg. J. Marciniuk, det. B. Trávníček

T. haematicum G. E. Haglund ex H. Øllg. et Wittzel

Ruderalia

Tworki, wet meadow, 18.05.2004, leg. J. and P. Marciniuk, det.B. Trávníček;
Żdżary, meadow, 13.05.2004, leg. J. and P. Marciniuk, det. T. Grużewska, conf. H. Øllgaard;
Podlaskie Swamp, Biebrza National Park, wet meadow, 9.05.2004, leg. J. Marciniuk, det. T. Grużewska, conf. H. Øllgaard

T. hemicyclum G. E. Haglund

Ruderalia

Zabuże, Trojan Reserve, Bug river walley, meadow, 2.05.2004, leg. J. and P. Marciniuk, det. B. Trávníček;
Książ Wielkopolski, Wielkopolska National Park, hause garden, 2.05.2003, leg. A. Czarna, det. Z. Głowacki, conf. H. Øllgaard

T. hepaticum Rail.

Ruderalia

Samowicze, meadow in Bug river valley, 11.05.2005, leg. J. and P. Marciniuk, det. H. Øllgaard;
Zawory, Śrem commune, 27.05.2003, leg. A. Czarna, det. H. Øllgaard

T. sinuatum Dahlst.

Ruderalia

Kisielany, meadow in Liwiec river valley, 17.05.2004, leg. J. and P. Marciniuk, det. B. Trávníček;
Polanowo Powidz commune, 9.05.2002, leg. Z. Głowacki, det. H. Øllgaard

T. melanostigma H. Lindb. ex Markl.

Borea

Poznań-Radojewo, meadow in Warta river valley, 7.05.2002, leg. Z. Głowacki, det. H. Øllgaard

T. vindobonense Soest

Palustria

Tworki near Wiśniew, wet meadow, 18.05.2004, leg. J. and P. Marciniuk, det. J. Štĕpánek

T. paucilobum Hudziok

Palustria

Mścichy, Biebrza National Park, dam, 8.05.2004, leg. J. Marciniuk, det. J. Štĕpánek;
Brzostowo, Biebrza National Park, wet meadow, 8.05.2004, leg. J. Marciniuk, det. J. Štĕpánek

T. scanicum s.str. Dahlst.

Erythrosperma

Ławki Swamp, Biebrza National Park, wet meadow, 9.05.2004, leg. J. Marciniuk, det. Radim J. Vašut

RESULTS AND DISCUSSION

Taraxacum copidophyllum Dahlst. belongs to Ruderalia section with distinct morphological references to the Palustria section. Bound with humid meadows from the Molinietalia order. The species was found in Poland (known from a dozen or so locations). The number of chromosomes, stated by us, is 2n = 24 (Fig. 1 a). Similar data have been reported (exclusively outside of Poland) by Danish and Dutch authors: 2n = 24 [34], 2n = +/- 24 [8].

Fig. 1. Somatic metaphases of the taxa studied. a. Taraxacum copidophyllum 2n = 24, b. T. freticola 2n = 24, c. T. freticola 2n = 16, d. T. haematicum 2n = 24, e. T. hemicyclum 2n = 24, f. T. hepaticum 2n = 24, g. T. sinuatum 2n = 24, h. T. melanostigma 2n = 24, i. T. vindobonense 2n = 32, j. T. paucilobum 2n = 26, k. T. scanicum 2n = 24. Scale bars = 10 µm

Recently described Taraxacum freticola H. Øllg. species is from the Ruderalia section [28], and was discovered in two arranged locations in the southern part of Poland. According to our studies there are two numbers of chromosomes present in this species: 2n = 24 (Fig. 1 b) and 2n = 16 (Fig. 1 c). Data on numbers of chromosomes for this species were not been published so far.

T. haematicum G. E. Haglund ex H. Øllg. et Wittzel is characteristic species from the Ruderalia section with morphological references to the Celtica section. In Poland the species come across relatively rarely on extensively used meadows from the Molinietalia order. The number of chromosomes found by us is 2n = 24 (Fig. 1 d). According to other authors from England and  the Netherlands, the number is: 2n = 24 [30,32], 2n = 24 [5], 2n = 24, 26 [8].

T. hemicyclum G. E. Haglund is quite common in Poland and belongs to Ruderalia section found often in meadow and ruderal habitats. According to our studies it contains 2n = 24 chromosomes (Fig. 1 e). Older data have been reported from Finland – 2n = 24 [33].

Another species belongs to Ruderalia section is T. hepaticum Rail. which is one of the commonest dandelions in Poland. It is growing in ruderal habitats and meadows. Like  T. hemicyclum it contains 2n = 24 chromosomes (Fig. 1 f). We were unable to get  reference, where the number of chromosomes of this species would be reported.

T. sinuatum Dahlst. is another quite frequent species from the Ruderalia section. It is appearing on meadow habitats and more rarely in ruderal locations. As well as the previously described dandelion species, it contains 2n = 24 chromosomes (Fig. 1 g). Prior data, concerning the number of chromosomes in this species come from England and the Netherlands: 2n = 24 [5], 2n = +/- 24 [8].

T. melanostigma H. Lindb. ex Markl. is rare species from the Borea section, connected with humid meadows. Stated by us number of chromosomes 2n = 24 (Fig. 1 h). We didn't reach to priorer details about the number of chromosomes of this species.

T. vindobonense Soest species from the Palustria section, in Poland dispersed, mainly in the southern part of the country, is closely connected with humid, extensively used meadows from the Molinietalia order. Number of chromosomes stated by us 2n = 32 (Fig.1 i). Priorer data from Poland: 2n = 32 [25], from Czech Republic: 2n = 32 [13].

T. paucilobum Hudziok, is the commonest species from the Palustria section in Poland, appearing in all sorts of communities in humid meadows. We stated in this species aneuploidal number of chromosomes 2n = 3x +2 = 26 (Fig. 1 j) for the first time. In earlier examinations they stated triploidal 2n = 24 number of chromosomes, data come from the area of Poland [23,24,25 as T. austrinum] and Czech Republic [10].

T. scanicum Dahlst. s.str. is species from Erythrosperma section. Relatively recently some morphotypes have been separated from Taraxacum scanicum s.l. into autonomic taksa [34,39]. All the prior data concerning cytology and chorology involve Taraxacum scanicum s.l. species. The number of chromosomes, stated by us is 2n = 24 (Fig. 1 k) and it is the first such data ever reported for this species T. scanicum s. str. Prior data concerning this species from the area of Poland state the number of chromosomes 2n = 25 [21,22], and these from England, German and the Netherlands: 2n = 24 [2,4,31].

CONCLUSIONS

With karyologic methods we determined the number of chromosomes in 10 species of the genus Taraxacum including six from the section Ruderalia, two from the section Palustria, one from the section Borea and one from the section Erythrosperma.

In the case of Taraxacum freticola we found the occurrence of triploid (2n = 3x = 24) and diploid (2n = 2x = 16) forms. The appearance of diploid forms is particularly interesting in this species. This indicates that the species is able to produce reduced, ovules capable of being fertilized. The number of chromosomes in T. freticola is given for the first time.

For the first time the number of chromosomes is also given for narrowly understood Taraxacum scanicum s. str. (2n = 24). To date reports (also from Poland) on the number of chromosomes referred to the complex of species T. scanicum s. l. [2,4,21,22,31]. This complex has recently been divided into several narrowly understood species [34,39]. The numbers of chromosomes in T. hepaticum – 2n = 24 and T. melanostigma – 2n = 24 given by us are probably the first ever reported.

New hipertriploid number of chromosomes 2n = 3x+2 = 26 we found in Taraxacum paucilobum. So far, eutriploid number of chromosomes 2n = 2x = 24 was given for this species  [10,23,24,25 as T. austrinum]. Małecka [23,24,25] gave also the number 2n = 25 for the form minor she distinguished, it is not, however, clear whether specimen attributed to this form belonged to the species T. paucilobum.

For the first time the number of chromosomes are given for specimen from Poland representing the four next species: T. copidophyllum – 2n = 24, T. haematicum – 2n = 24, T. hemicyclum 2n = 24 and T. sinuatum 2n = 24. They fully agree with data from other European countries [5,8,35,33].

We confirmed tetraploid 2n = 4x = 32 number of chromosomes in Taraxacum vindobonense reported earlier from Poland [25] and Czech Republic [13].

ACKNOWLEDGEMENTS

We thank Mr. Hans Øllgaard, Dr. Jan Štĕpánek, Dr. Bohumil Trávníček and Dr. Radim J. Vašut for identification of the herbary material, Prof. Zygmunt Głowacki and Dr. Aneta Czarna for providing access to their plant collection.

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Accepted for print: 7.11.2008


Anna Grzesiuk
Department of Plant Physiology and Genetics,
University of Podlasie, Poland
B. Prusa 12, 08-110 Siedlce, Poland
email: grzesiuk@ap.siedlce.pl

Jolanta Marciniuk
Department of Botany, Institute of Biology,
University of Podlasie, Siedlce, Poland
B. Prusa 12, 08-110 Siedlce, Poland

email: jolam@ap.siedlce.pl

Paweł Marciniuk
Department of Botany, Institute of Biology,
University of Podlasie, Siedlce, Poland
B. Prusa 12, 08-110 Siedlce, Poland

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