DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu
| ŠUMARSKI LIST 1-2/2016 str. 37 <-- 37 --> PDF |
accumulated the lowest mean concentration of iron (Table 2). The established values are in accordance with the reports of Rudawska and Leski (2005a, b). Extraordinarily high concentration of iron (1304–2075 mg kg –1) was found in Suillus variegatus (Borovička and Randa, 2007). This species is well known as an accumulator of Fe (Valiulis et al. 1995; Falandysz et al. 2001, Kalač, 2010). Moreover, iron is distributed unevenly within a fruit body, with the highest contents in the cap, and lower in the stipe, which is in accordancet with previously reported results (Kalač 2010; Falandysz et al. 2011; Kojta et al. 2011; Jarzynska and Falandysz 2012). Iron content of macrofungi is generally lower than that in soil (Table 1). Consequently, the BCF of all mushrooms species for iron was lower < 1, which implies that all the investigated mushrooms species are bioexclusors of iron. These results are in major agreement with the results of Malinowska et al. (2004). Accumulation of zinc in the investigated species of fungi is close to the accumulation of iron, although the concentration of zinc in the analysed samples of soil was considerably lower than the concentration of iron (Table 1). According to different authors, concentrations of zinc in mushrooms ranges from 21 to 110 mg kg–1 (Cayir et al., 2010), 30 to 150 mg kg–1 (Kalač,2010), 35 to 136 mg kg–1 (Radulescu et al., 2010) and 29 to 146 mg kg–1 (Sarikurkcu et al., 2011). The values of zinc in this study were in the previously specified range. The lowest concentration of zinc determined in the species A. mellea can be explained by lifestyle of mushrooms, because it is a lignocellulous species that lives on wood without contact with mineral particles of soil. This is in accordance with studies of Campos (2011), which have confirmed the lowest content of zinc in A.mellea. The highest mean value in T. terreum, can be explained that zinc adapted to ectomycorrizal fungi can be used as biological barriers to the accumulation of metals in symbiotic trees Adriansen et al. (2006), thereby increasing the concentration of zinc in the fruit bodies of mushrooms. The lower accumulation of zinc in the saprophytic species can be caused due to microbial immobilization of zinc, but also because of antagonism of zinc with phosphor, calcium, manganese, iron and cooper. A considerably higher concentration of zinc in the cap than in the stipe determined for all species examined in this study is in major agreement with the results of Rudawska and Leski (2005a, b) and Alonso et al. (2003). Bioconcentration factor was mostly < 10 Kalač (2010), which is in an agreement with our results, although some species of mushrooms were found to be bioexclusor for zinc (BCF<1). The concentration of cooper was significantly different (p<0,001) between life style of investigated fungi. This is in accordance with the results of Alonso et al. (2003), who found significantly higher (p<0,001) cooper concentration in the saprophytic compared to ectomycorrhizal species of fungi. According to data of Kalač (2010), cooper contents in the most species of mushrooms from unpolluted areas may vary between 20 and 100 mg kg–1, with a few exceptions in species with high bioaccumulative potential, such as Agaricus macrosporus, Agaricus silvaticus, Macrolepiota procera (Alonso et al. 2003; Svoboda and Chrastny, 2008). Accordingly, the present study demonstrates the highest mean values of cooper in M. procera (p<0.001). The opposite was found for ectomycorrhizal species L. deterrimus, where the lowest concentration of cooper was determined (Table 2), which is equivalent to the results of Aloupi et al. (2012). This could be due to symbiotic lifestyle of the ectomycorrhizal species L. deterrimus (Aloupi et al., 2012). Higher deposition of copper in the cap versus the stipe determined in our study is in agreement with the results of Kojta et al. (2011) and Jarzynska and Falandysz (2012). Also, Kalač (2010) determined shows higher content of cooper in the cap than in the stipe in several mushroom species from the family Boletaceae. Available scientific literature does not mention the reason for the higher accumulation of nickel in the cap than in the stipe. A possible explanation for this is not just higher biological activity in spores, which are part of the cap (Chang and Chan, 1973), but also the possibility of the influence of atmospheric deposition, depending on the area of mushroom sampling. In this study, all metals bioconcentration factors were below 1 in the ectomycorrhizal species of mushrooms, which suggests that ectomycorrhizal species are bioexclusors of cooper. We consider that higher bioconcentrations of cooper in saprophytic species M. procera, that develop mycelium in the upper horizon of the soil. Our results are in agreement with values reported by Alonso et al. (2003). Grouping of the species based on the concentration of heavy metals in their fruit body (hierarchical cluster analysis) revealed that species of the same genus have a similar ability to accumulate metals from their growing environment. The similar nutritional habits of species belonging to the same genus were probably the major reason for such consistent clustering of species on the basic level. This clustering was mainly in accordance with our expectations, bearing in mind that species within the same genus share some common physiological characteristics. Grouping of the species in separate clusters on the next level was more or less in accordance with our expectations, since the majority of analysed species (or even whole genera) were separated in clusters in accordance with their ecological affiliation (ectomycorrhizal and saprophytic species). However, this clustering was not completely consistent, since species of the genus Tricholoma were found to be more similar to the terrestrial saprophytes than to members of its own ecological affiliation. In view of the ecological habits of the examined species, the positioning of M. procera within a separate cluster can also be considered to be a partially unexpected result. This species is a terrestrial saprophyte, and we |