DIFFERENTIATION OF MORPHOLOGICAL TRAITS OF COMMON TANSY ( TANACETUM VULGARE L.) ORIGINATING FROM DIFFERENT STANDS

The aim of the study was to determine the effect of pH and soil chemical composition on morphological traits of common tansy ( Tanacetum vulgare L.). A two-year study was conducted based on observations, measurements and analyses of material collected from 24 stands in the following regions: Równina W ł oc ł awska (W ł oc ł awek Plain), Wy ż yna Lubelska (Lublin Upland), Padó ł Zamojski (Zamo ść Depression), Dzia ł y Grabowieckie (Grabowiec Divide) P ł askowy ż Suchedniowski (Suchedniów Plateau), Wysoczyzna Siedlecka (Siedlce High Plain) and Niecka Po ł aniecka (Po ł aniec Basin). Morphological traits of tansy shoots were determined: number of plants per clump, stem length, number of leaves per plant, total leaf length, petiole length, number of branches from the main stem, number of ﬂ ower heads per corymb and ﬂ ower head diameter. A soil analysis was performed determining the content of magnesium, potassium and phosphorus available for plants. The soil pH was also determined. The collected results indicate signi ﬁ cant differentiation of the investigated samples, both in terms of morphological traits of the shoots and the chemical composition of the soils. A negative correlation was found between soil pH and number of leaves per shoot as well as number of branches per corymb. A positive correlation was noted between soil pH and total leaf length as well as between magnesium content and number of ﬂ ower heads per corymb. The increased content of available phosphorus in the soil was associated with petiole shortening. A growth trend in the tansy shoot length was observed at larger amounts of available magnesium in the soil. On soils with low nutrient availability and a low pH, a reduced population density of the species in question was observed.


INTRODUCTION
Because of its anthelmintic and antiparasitic properties, tansy has been commonly used in folk medicine.
Research has been recently conducted on the use of Tanacetum vulgare leaf extracts as a medicine with diuretic properties (S a n a a et al. 2007 ). Today, due to toxicity of beta-thujone contained in the oil, tansy is mainly used externally in skin diseases. For some time, dried shoots of this plant have been used as ornamental material for dried fl ower arrangements. In Poland tansy occurs commonly, forming numerous stands in thicket communities, in forest fringe communities, at ruderal sites (S z w e y k o w s c y , 2003). Tanacetum vulgare L. is commonly found across the whole country (Z a j ą c and Z a j ą c , 2001). It is due to the availability of this plant that an attempt has been made to determine, based on soil analysis results, the effect of habitat conditions on certain morphological traits of tansy shoots.

MATERIALS AND METHODS
The study was carried out in the years 2005 and 2007. 24 natural common tansy stands were selected from different Poland's regions: Równina Włocławska (Włocław Plain), Wyżyna Lubelska (Lublin Upland), Padół Zamojski (Zamość Depression), Działy Grabowieckie (Grabowiec Divide) Płaskowyż Suchedniowski (Suchedniów Plateau), Wysoczyzna Siedlecka (Siedlce High Plain) and Niecka Połaniecka (Połaniec Basin). From each site, a soil sample was collected from the soil layer of 0-20 cm and biometric measurements of plants were made. In the soil, the content of macroelements: potassium and phosphorus, was determined using Egner-Riehm's method, magnesium using the colorimetric method and the pH by means of the potentiometric method in 1 n KCl.
At the turn of July and August each year, during the full fl owering period, biometric analyses were performed in three replications. The characteristics of shoot morphological traits included the following: number of plants per clump, stem length, number of leaves per plant, total leaf length, petiole length, number of branches from the main stem, number of fl ower heads per corymb and their diameter.

RESULTS AND DISCUSSION
The soil reaction in the natural tansy stands was quite varied; the pH in KCl was from acid -4.0 ( stand no. 3), to alkaline -7.4 (stands no. 6., no. 15., no. 22.). The obtained results show high tolerance of this plant to the hydrogen ion concentration in the soil. However, only in 8.4 % of the stands concerned, a pH below 5.0 was found. This result may prove that common tansy prefers slightly acid and neutral soils. This fi nding fi nds confi rmation in a paper characterising some morphological features of vascular plants of the Lublin region (F i j a ł k o w s k i , 1994). The author gives a soil pH from 5.5 to 6.5 as the optimal soil reaction.
Soils of mainly loess origin, with high nutrient availability, were characterised by a higher soil pH (stand no. 6, 8, 15).
The mineral content varied strongly. The plants grew equally well on soils with a very high content of phosphorus (50 mg 100 g -1 soil) and potassium (30 mg 100 g -1 soil), where the tansy shoot length reached 141.3 cm, and in stands defi cient in these nutrients (1.7 mg P 100 g -1 soil and 1.6 mg K 100 g -1 soil) (Tab. 1.) in which the length of the plant shoot was 104.6 and 163.3 cm, respectively (Tab. 2). Soil conditions characterising nutrient requirements of the plant in question were marked by high diversity, also in terms of magnesium availability. Tansy occurred in stands with a large (15.7 mg Mg 100 g -1 soil) and even trace amount of this element in the soil (1.0 mg Mg 100 g -1 soil (Tab. 1).
In available literature, no reference has been found relating to nutrient requirements of Tanacetum vulgare L., however, a paper on the distribution of this species in Poland indicates the common occurrence of tansy throughout the whole country (Z a j ą c and Z a j ą c , 2001). Such common availability of this plant undoubtedly proves the high tolerance of the species in question to the content of bioelements in soil.
Measurements related to the growth and fl owering of the herb prove large differentiation in terms of morphology of this plant.
Tansy grew most frequently in clusters forming clumps with a different number of shoots, from 8.0 -stand no. 21 -up to 39.3 in stand no. 4. The shoot length was also quite varied; the plant developed shoots with a height from 66 cm to 163 cm. These values are higher by, respectively, 5.5 and 47.9 cm than the results given in a paper relating to genetic and morphological diversity of tansy (K e s k i t a l o et al. 1998). The authors of this article also estimated the number of fl ower heads per corymb, which was from 17.6 to 79.8. The range of results in our study was much wider. Differences in the shoot length given by S z a f e r et al.
(1969) -from 50 to 150 cm, are similar to the results obtained in our study.
The plants were characterised by large variability in leaf morphological traits, notably, the number of leaves per shoot ranged between 7.3 (stand no. 4) and 37 (stand no. 3.) and it was in no way dependent on the number of shoots per clump or their length.
Total leaf length and petiole length also had different values not related to other morphological traits of the herb. The longest leaves were observed on the plants from stand no. 13. (25.5 cm) and the same plants were characterised by the longest petioles. The smallest total leaf length related to the plants from stand no. 22. and it was 12.5 cm.
The shortest petioles (1.5 cm) were found in Czesławice in stand no. 8.
Large differences in the number of branches in corymbs from 7 (stand no. 1) to 20 (stand no. 17.) did not determine the correlation between the equally varied number of fl ower heads per corymb (26.8 at stand no. 14. and 310.6 at stand no. 23.).
The fl ower head diameter ranged from 0.55 cm in stand no. 8. to 1.07 cm in Lublin -stand no. 4. The abovementioned data evidence large variability of this trait. These results are consistent with the range of fl ower head diameters given by B r o d a and M o ws z o w i c z (2000), which is from 0.8 to 1.1 cm in their paper. Taking into account the fact that infl orescences are herbal raw material and they contain more oils than leaves by 36.7 % and by as much as 69.4 % than the herb, the fl ower head diameter will affect an increase in yield (W i e r z c h o w s k a -R e n k e et al. 1997).
All the abovementioned traits, both of substrate and plant morphology, indicate the high tolerance of tansy in relation to the soil reaction as well as phosphorus, potassium and magnesium content in soil.
A factor modifying the plant growth, expressed by the shoot length, was the availability of assimilable magnesium in the soil. At the majority of the sites, a high content of this element in the soil solution promoted the growth of the developed shoots (Tab. 3). This correlation was not observed in all the stands   Table 2 Plant morphological traits.  (stands no.: 1, 2, 14, 19, 22, and 24.). Most probably, other habitat factors were active at these sites, limiting the uptake of the bioelement or making the plant height independent of the amount of the respective nutrient in the soil (Tab. 2., stands no. 19. and 24. ). An example may be a forest stand (Włocławek no. 2.) where the extensive shading of this area was probably the cause of the plant's limited growth (73.3 cm. But, in the same city in a stand near the Zgłowiączka River (113.3 cm) and in Połaniec on the Vistula river (88.6 cm), the small shoot length, compared to the magnesium content in the soil, was most probably attributable to disturbances in the uptake of this element. These sites were periodically inundated. The longest tansy shoots measured in the following stands: no. 4. Lublin Felin boundary strip (147 cm) and no. 24. Połaniec fallow fi eld (163.3 cm), prove that a low magnesium and potassium content in the soil (Tab. 1.) is not a factor limiting the growth of Tanacetum vulgare.
The correlation between shoot length and magnesium content in the soil does not fi nd any confi rmation in scientifi c literature.
The analysis of the correlation showed a negative correlation between soil reaction and number of leaves per shoot (-0.50) and number of branches per corymb (-0.31). A positive correlation was noted between soil pH and total leaf length (+0.42) as well as between magnesium content and number of fl ower heads per corymb (+0.37).
The level of available phosphorus in soil was found to be negatively correlated to petiole length (-0.33).
No other correlations were found between the content of macroelements in the soil and morphological traits of the plants. A benefi cial effect of potassium on plant conformation and a negative effect of phosphorus on number of shoots and branches of St. John's wort were found in a paper by B ł a ż e w i c z -W o ź n i a k and K ę s i k (2001). A negative correlation was also shown between the magnesium level in the soil and the height of the investigated plants.
Large differentiation in morphological traits of tansy is most probably associated not only with soil chemical conditions, but also with other habitat factors such as: light, interspecifi c competition and the anthropogenic factor. CONCLUSIONS 1. Common tansy plants were characterised by large differentiation in the morphological structure of their shoots. 2. Tansy grew well both on soils with an acid and neutral reaction. In natural stands, however, it prefers soils with a higher pH. 3. The species Tanacetum vulgare L. occured in stands with a very varied content of the following nutrients: potassium, phosphorus and magnesium. 4. A positive correlation was demonstrated between soil reaction and total leaf length, as well as a negative effect of soil pH on number of leaves per shoot and number of branches per corymb. 5. The magnesium level in the soil had a benefi cial effect on number of fl ower heads per corymb. 6. A negative correlation was noted between phosphorus content in soil and petiole length.