Akademik Veri Yönetim Sistemi
5TH INTERNATIONAL PLANT SCIENCE AND TECHNOLOGY CONGRESS, İstanbul, Türkiye, 28 Ekim 2022
Abstract
Centaurea hermannii F. Hermann (syn: C. sisymbriifolia Arènes) is an endemic plant described from İstanbul,
Turkiye. It is listed in the Red Databook of Turkish Plants as an endangered species (Ekim et al., 2000). It is a
perennial plant with an erect, usually simple stem of 30-60 cm with decayed remains of petioles at the base. Leaves
are sparsely pilose, lyrate, basal and lower leaves are petiolate. Flowers are orange, marginal and not radiant.
Achenes are 3-6 mm long, 0,5- 2,8 mm wide; pappus 5,5 – 10,5 mm long. Flowers are present usually from late
May through June and early July. Resides under Quercus or Pinus forest cover usually away from direct sunlight
at an elevation of between 100-500m.
Based on the idea that C. hermannii being an endemic plant may suggest that the regions where it grows may also
have a special soil mineral element composition, special micro and macro climates and ecological conditions, soil
samples taken from the regions where this plant grows were examined in terms of heavy metal and mineral
elements, and the results were compared with the heavy metal and mineral element levels found in different parts
of the plant such as stem, root and leaves. Analyzes of Al, B, Ca, Cd, Cr, Co, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and
Zn elements were performed with the ICP-OES device. A soil and six plant samples were taken from the two
different populations of C. hermannii. The samples were then dried and measured and average values were
obtained for further evaluation.
The characteristics of two locations that the samples were taken from are distinctive and deemed effective in heavy
metal and mineral nutrient contents of the samples. First location, Arnavutköy is very close to busy road traffic
and prone to heavy metal exposure in comparison to Aydos location which is far from roads, with slightly higher
elevation and less human exposure. In this regard, the results obtained are as expected, since the levels of all 15
elements in soil samples were higher in Arnavutköy samples. Differences of element levels varied between as low
as 5% in Fe and K, and as high as 20% in Cr, Co and Cu, and 23% in Ni contents. This difference can also be
observed in plants parts when the two locations are compared; with the stem and root samples from Arnavutköy
location containing higher amounts of all elements tested, whereas 13 elements were measured higher in leaf
samples from Arnavutköy with the exception of Cr and Fe.
When the heavy metal and mineral element levels were separately evaluated, Ca, Cd, Fe, K, MN, Na, Ni levels
were within normal limits in all plant parts from both locations. Al and B levels were 30-50% higher in root
samples of both locations and within normal range in leaf and stem samples. Cr and Cu levels were above normal
levels in all samples from both locations. Zn, Pb, Co and Mg levels were elevated in leaf and root samples from
both locations. To summarize briefly, none of the elements were above toxic threshold with the exception of Cu
for all samples and ZN for leaf and root samples from both locations.
These results show that this endemic plant is not yet under heavy metal stress, but still exposed to heavy metal
stress above normal levels. In the medium and long term, the possibility of changing the threat category should be
evaluated as a result of the difficulties that this plant may experience in adapting to both habitat loss and increased
heavy metal exposure with growing urbanization and increased traffic congestion.
Keywords: Heavy metal stress, Plant conservation, habitat loss, Extinction threat