Seeds of Oxyccocus Palustris Pers. from Ericaceae Family

Biology of germination of medicinal plant seeds. Part XXIII: Seeds of Oxyccocus palustris Pers. from Ericaceae family

WALDEMAR BUCHWALD*, JAN KOZŁOWSKI, ELŻBIETA BILIŃSKA

The Branch of Medicinal Plants of the Institute of Natural Fibres and Medicinal Plants Libelta 27 61-707 Poznań, Poland

*corresponding author: [email protected], phone: +4861 6517190, fax: +4861 6517192

S u m m a r y

At the beginning a short characteristic of Ericaceae family is elaborated then the biology of seeds germination of Oxyccocus palustris Pers. is described. In this experiments, the optimal condition of ability of germination of Oxyccocus palustris Pers. was established. It was found that the light and variable temperature (30oC over 8 hours, 20oC over 16 hours) were optimal for analysis of Oxyccocus palustris seed germination ability. The results also show that the pre-sowing treatments (stratification) were significant to obtain a higher percent of germinating seeds in comparison to non-stratified seeds. The capacity of germination of Oxyccocus palustris Pers. seeds stored in unheated room conditions gradually decreased in the first year after harvest. The viability of Oxyccocus palustris seeds is very short. Three years after harvest time, the seeds do not germinate.

Key words: Ericaceae family, Oxyccocus palustris Pers., germination, seeds

INTRODUCTION

The characteristics of Ericaceae family

In Poland 15 species from 10 genera belonging to Ericaceae family are noticed [1-5]. It is relatively few taxa in comparison to 82 genera and to over 2,500 species widespread all over the world. The plants appear as a dwarf shrub, sub-shrub, shrub or a small tree, usually with alternating leathery and often evergreen leaves. The bisexual flowers are Biology of germination of medicinal plant seeds. Part XXIII: Seeds of Oxyccocus palustris Pers. from Ericaceae family 15

solitary (axillary or terminal) or clustered in inflorescences. The corollas are usually radially symmetrical, although, many flowers of the family are somewhat bi- laterally symmetrical. Moreover, the corollas are also composed of wholly fused, rarely partial petals. There are from 8 to 10 (alternatively with petals) stamens with anthers dehiscing by terminal pores. The carpel is superior or inferior and contains many ovules. In Ericaceae family, the fruit can have a shape of a capsule, a berry or a drupe. As long as the fruit does not achieve full ripeness, the calyx remains on its surface. The embryo of seeds is straight, its length takes up 2/3 of whole seed. The basic number of chromosome 2n is: 8, 11, 12, 13 [1, 3, 6]. The species of Ericaceae family grow mainly in polar zone and in higher mountainous sites [1-4, 7-9]. In order to obtain normal phase of plant development, most of the species need acid soil. Due to great difficulties caused by species diversity among the family, some of the scientists divide the family into two independent taxa: Ericaceae – containing flowers with superior carpel and a capsule as a fruit, and Vacciniaceae – in which all the plants have an inferior capsule in the flower and a fleshy fruit (berry) [5]. Almost always the fruit contains many small seeds ranging from 0.2 to 3.5 mm of length [5]. The seeds are well-supplied with nutritious material such as proteins and fat. The shape of the seeds varies from round-ovate to flat. Many species of Ericaceae family are used in industry. The plants which are able to produce berries are very useful in food and pharmaceutical processing. Species containing essential oils are of practical application in cosmetics and medicine. Many species are also well-known as ornamental plants [2, 10, 11]. The herbal medicine in Poland is very interested in some species of this family. The most important species are as follows: Ledum palustre L., Vaccinium myrtillus L, Vaccinium vitis idea L., Arctostaphylos uva-ursi (L). Sprengel, Calluna vulgaris Salisb., Oxyccocus palustris Pers. [2, 10, 11]. This part of the work elaborates on Oxyccocus palustris Pers. which is of great significance in healing and food processing.

The diagnostic features of Oxyccocus palustris Pers. – a plant description

The plant of this species is a shrub with a flexible, trailing along the ground stem with length coming up to 1 m. Dark, shiny evergreen leaves are alternating and almost sessile. The shape of the leaves is oblong-ovate, 5–12 mm long and 3–5 mm wide. Four-merous flowers are clustered in (axillary or terminal racemes) with inflorescence of 1–5. The flower occurs on (more or less) erect, red and slen- der, pubescence pedicels. The pinkish corolla is divided (towards the base) into lobes. There are 8 stamens and 1 style, nectar is produced on the base of the style [12, 13]. The fruit of Oxyccocus palustris Pers is red, 8–10 mm in diameter, edible berry [1-3, 5, 8, 9, 11]. The fruit can stay on the plant until spring. The number of seeds in berry ranges from 3 to 11. Seeds are from linear, ovate to almost circular, sharply pointed at one side. Seeds are 1.5–2.8 mm long,

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1.0–1.8 mm wide and 1.0–1.8 mm thick [7, 14]. The colour of seeds is yellowish to red-brown without sheen. The seed coat is reticulate. Oxyccocus palustris Pers. is distributed in Central and North Europe and spread from the Balkans, the Ural Mountains, Siberia to Manchuria [8, 9]. In Poland, the species is indigenous to peat bogs, usually in wetter parts. The plant usually makes a loose turf on the edge of transitional moor. In natural sites the highest number of plants has been noted in North and Central Poland, whereas in the foothills and in the mountains it is sparse [15]. The Oxycoccus palustris Pers. is a species characteristic for ombrotropic peat bog (Sphagnetalia magellanici order) [16]. The chromosome number of Oxyccocus palustris is 2n=48,60,72. The ploidy leavel of cranberry have an influence on the size of the flower (6).

Materials and Methods

Seeds of Oxyccocus palustris Pers. were picked from native sites in North Poland (near Wronki) at the stage of ripe fruit. The collection was carried out at the end of September and in the first part of October in 2006 and 2007. Every year after harvest, the fruit tissue was removed. Cleaned and dried diasporas were stored in paper bags in unheated room conditions. In the experiments, in order to compare the results of germination, a part of the seeds was stratified (in moist sand, temperature 5OC), the remaining seeds were tested without pre-sowing treatments. Analyses of germination were carried out according to ISTA seed estimation methodology. Blotting chromatography paper (Whatman 3) was used as a basis. The physical conditions used during the analyses of germination ability were as follows: light and changing temperature, darkness and changing temperature, light and constant temperature. The seeds germinated on Petri dishes in constant temperature of 20oC in day- light. The climate chamber was applied to obtain darkness and changing temperature (30oC for 6 hours and 20oC for 18 hours), while the Jacobsen apparatus was used to make the temperature change (30oC for 8 hours and 20oC for 16 hours). The results of germination analyses of stratified and non-stratified Oxyccocus palustris Pers. seeds were tested monthly from December 2006 to October 2007 and from December 2007 to October 2008.

Diagnostic features of seeds and seedlings

The seeds are contained in a fleshy, red berry with lathery pericarp. The shape of the seeds is linear, ovate to nearly circular with a reticulate surface. One side of the seed is sharply pointed. Its colour is from yellowish to dark brown or reddish to dark brown without sheen (phot. 1). Seed dimensions are as follows: length Biology of germination of medicinal plant seeds. Part XXIII: Seeds of Oxyccocus palustris Pers. from Ericaceae family 17

1.0–3.0 mm, width 0.9–1.9 mm and thickness 1.0–1.8 mm. The seed number of berry ranges between 3 and 11. The mass of 1.000 seeds varies from 0.982 to 0.990 g. The radicle appears in the narrow part of the seed (phot. 2), in 7th–9th day from the test beginning. The radicle is white and thin and gets longer in consecutive days. After 15 days, the lateral roots grew in the oldest part of radicle. Coming out of the cotyledons is the next phase of the plant development (phot. 3, 4). This process is observed between 20 and 25 days of analyses. Cotyledons are shiny green, smooth and their shape is lanceolate.

Germination of seeds

Numerous reports on Oxyccocus palustris were found in extensive research con- cerning natural site, the “rhythm” of development, fruit yielding and its usage in medicinal and food industry [2, 10, 11, 17-19]. Unfortunately, there is not much literature on the biology of germination of Oxyccocus palustris seeds [12]. It might be due to the fact that the plants are usually propagated by vegetative reproduction. The aim of the study was to ascertain the biology of germination of Oxyccocus palustris seeds. During the first year of analysis, the methodology of seed germination was checked. After three months from the experiment beginning the methodology was extended by a variant of stratified seeds. It was found that, in laboratory conditions, the light and variable temperature (30oC over 8 hours, 20OC over 16 hours) were optimal for analysis of Oxyccocus palustris seed germination ability. The results show that the pre-sowing treatments (stratification) were significant to obtain a higher percent of germinating seeds in comparison to seeds which were non-stratified (fig. 1, 3). Figure 2 and 4 shows the ability of stratified seeds to germinate.

20 light+changing temperature 18 darkness+chanching temperature 16 light+constant temperature 14 12 10 8 6 4 2 Seed germination capacity % Seed germination capacity % 0 XII II II III IV V VI VIIVII VIII IX X MonthsMonths Figure 1. Germination capacity of Oxyccocus palustris Pers. seeds in the first year after harvest – 2006. Non-stratified seeds

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Phot. 1. Oxyccocus palustris Pers. seeds Phot. 2. Germination of Oxyccocus palustris Pers. seeds

Phot. 3. Seedlings of Oxyccocus palustris Pers. Phot. 4. Oxyccocus palustris Pers. seedlings in a subsequent development stage Biology of germination of medicinal plant seeds. Part XXIII: Seeds of Oxyccocus palustris Pers. from Ericaceae family 19

4545 light+changinglight+changing temperature temperature 4040 darkness+chanchingdarkness+chanching temperature temperature 3535 3030 2525 2020 1515 1010 55 Seed germination capacity % Seed germination capacity % 00 III IV V VI VII VIII IXIX X Months Months Figure 2. Germination capacity of Oxyccocus palustris Pers. seeds in the first year after harvest – 2006. Stratified seeds light+changinglight+changing temperature temperature darkness+chanchingdarkness+chanching temperature temperature 90 light+constantlight+constant temperature temperature 80 70 60 50 40 30 20

Seed germination capacity % 10 Seed germination capacity % 0 XIIXII I IIII III IVIV VV VIVI VIIVII VIIIVIII IXIX XX Months Months Figure 3. Germination capacity of Oxyccocus palustris Pers. seeds in the first year after harvest – 2007. Non-stratified seeds light+changinglight+changing temperature temperature darkness+chanchingdarkness+chanching temperature temperature 9090 light+constantlight+constant temperature temperature 8080 7070 6060 5050 4040 3030 2020 10 Seed germination capacity % 10 0 seed germination capacity % 0 XII I II III IVIV VV VI VIIVII VIII IX X MonthsMonths Figure 4. Germination capacity of Oxyccocus palustris Pers. seeds in the first year after harvest – 2007. Stratified seeds

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In laboratory conditions, the seeds collected in 2006 germinated poorly – up to 40%. Moreover, non-stratified seeds obtained from the same harvest germinated even worst – up to 20%. In addition, the seeds lost their viability after 3 months from the harvest. Much better results were obtained in the second year of the seed testing. The figure 4. shows the curve of the fluctuation of germination capacity in particular months, which varies from 40-80% during the whole year in different laboratory conditions. Non-stratified seeds sprouted a little worse but with bigger monthly fluctuation. Figure 3. shows the results. Diaspores stopped germinating in the last month of seed testing.

Viability of stored seeds

The capacity of germination of Oxyccocus palustris Pers. seeds stored in room conditions decreased both in the first and second year of experiment. The seeds collected in 2006 stopped germinating after 11 months. The germination of seeds gathered in 2007 decreased up to few per cent (non-stratified seeds) and up to 25% (stratified seeds) at the end of seeds testing. Viability of the seeds of Oxyccocus palustris is very short. Diaspores stored in the conditions of unheated room keep their viability to 2 years but their germination capacity is only few percent. Three years from harvest time, the seeds do not germinate.

ACKNOWLEDGEMENT

The research was financed by the Ministry of Science and Higher Education (grant No. N405 022 31/1319).

REFERENCES

1. Pawłowski B, Flora Polska, Rośliny Naczyniowe Polski i Ziem Ościennych. Vol. 10, Warszawa 1963. 2. Grochowski W. Uboczna produkcja leśna. Warszawa 1976. 3. Rutkowski L. Klucz do oznaczania roślin naczyniowych Polski Niżowej. Warszawa 1998. 4. Zając A, Zając M, (red.) Atlas rozmieszczenia roślin naczyniowych w Polsce. Kraków 2001. 5. Szkudlarz P. The morphological and anatomical structure of fleshy fruits in family Ericaceae. Biological Bulletin 1999; 36(1):43-56. 6. Suda J, Lysak MA. A taxonomic study of the Vaccinium sect. Oxycoccus (Hill) W.D.J. Koch (Ericaceae) in the Czech Republic and adjacent territories. Folia Geobotanica 2001; 36:303-20. 7. Brouver W, Stählin A. Handbuch der Samenkunde fűr Landwirtschaft, Gartenbau und Forstwirtschaft. Frankfurt am Main 1955. 8. Bailey LH. The standard cyclopedia of horticulture. Vol. 3. New York 1950. 9. Hegi G. Illustrierte Flora von Mittel-Europa, Bd.3, Muenchen 1927. 10. Rodowski D. Żurawina – nowe spojrzenie na właściwości lecznicze. Postępy Fitoterapii 2001; 6:28-31. Biology of germination of medicinal plant seeds. Part XXIII: Seeds of Oxyccocus palustris Pers. from Ericaceae family 21

11. Floryanowicz-Czekalska K, Wysokińska H. Oxycoccus quadripetalus Gilib. w kulturze in vitro. Biotechnologia 2004; 2(65):225-30. 12. Jacquemart AL. Vaccinium oxycoccos L. (Oxycoccus palustris Pers.) and Vaccinium microcarpum (Turcz.ex Rupr.) Schmalh. Journal of Ecology 1997; 85:381-96. 13. Gugnacka-Fiedor W. Zmienność morfologiczna taksonów rodzaju Oxycoccus Hill. Studia Societatis Scientiarum Torunensis. Sectio D (Botanica) 1986; 11(4):310-59. 14. Szkudlarz P. Morphological and anatomical structure of seeds in the family Ericaceae. Biological Bulletin 2001; 38(2):113-32. 15. Szafer W, Zarzycki K. Szata Roślinna Polski. Vol. 2. Warszawa 1977. 16. Matuszkiewicz W. Przewodnik do oznaczania zbiorowisk roślinnych w Polsce. Warszawa, 2001. 17. Baranec T, Durisova L, Kuna R. Generative reproduction of some endangered woody species from families Ericaceae Juss. And Vacciniaceae S.F.Gray in Slovakia. Biologia (Bratislava) 1996; 51(1):31-5. 18. Froborg H. Pollination and seed production in five boreal species of Vaccinium and Andromeda (Ericaceae). Canadian J Bot 1996; 74(9):1363-8. 19. Campbell DL, Rocheford L. Germination and seedling growth of bog plants in relation to the recolonization of milled peatlands. Plant Ecol 2003; 169:71-84.

Biologia kiełkowania nasion roślin zielarskich. Część XXIII: Nasiona Oxyccocus palustris Pers. Z rodziny Ericaceae

WALDEMAR BUCHWALD*, JAN KOZŁOWSKI, ELŻBIETA BILIŃSKA

Oddział Roślin Zielarskich Instytutu Włókien Naturalnych i Roślin Zielarskich ul. Libelta 27 61-707 Poznań

*autor, do którego należy kierować korespondencję: [email protected], tel.: +4861 6517190, faks: +4861 6517192

Streszczenie

W artykule przedstawiono ogólną charakterystykę rodziny Ericaceae, a następnie omówio- no biologię kiełkowania oraz opisano cechy morfologiczne nasion i siewek Occycocus palustris Pers. W badaniach ustalono optymalne warunki laboratoryjne do oceny zdolności kiełkowania nasion. Stwierdzono, że zabieg przedsiewny – trzydziestodniowa stratyfi- kacja w wilgotnym piasku i temperaturze 5oC, a także temperatura zmienna (20oC/30oC) zwiększają zdolność kiełkowania nasion. Nasiona żurawiny w ciągu pierwszych miesięcy po zbiorze kiełkują dość dobrze (40– 80%). Po tym okresie zdolność kiełkowania waha się. Żywotność materiału nasiennego przechowywanego w warunkach nie ogrzewanego magazynu utrzymuje się do dwóch lat po zbiorze.

Słowa kluczowe: rodzina Ericaceae, Oxyccocus palustris Pers., kiełkowanie, nasiona

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