Trakya University Journal of Natural Sciences, cilt.23, ss.1-13, 2022 (ESCI)
Abstract: This study is aimed at determining the characteristics and microbiota of soil upon which
some Turkish Colchicum (Colchicaceae) species naturally grows. For this aim the rhizosphere soil
samples of Colchicum balansae Planch., Colchicum triphyllum Kunze and Colchicum variegatum
L. were analysed in this research. The carbon mineralization rate of C. balansae soil at p<0.05 is
significantly different from that of the other two soils. In terms of nitrogen mineralization, significant
difference exists between all the three soils (p<0.001). Colchicum variegatum rhizosphere was found
to have the highest bacterial diversity. The results revealed that 254 bacterial species were common
to the three rhizosphere soils, 35.60% of the bacterial species were unique to C. variegatum soil while
21.89% and 22.67% of the bacterial species were unique to C. balansae and C. triphyllum soil
respectively. It was found that C. variegatum and C. balansae collected from areas close to each
other had the highest number of common bacterial species, while C. triphyllum from the distant
region shared 75 with C. variegatum and 19 with C. balansae. Metagenomics analysis reveals that
in the rhizophere of C. variegatum, C. balansae and C. triphyllum, Actinobacteria is dominant at
phylum level. Likewise, in C. variegatum soil, Nitrosocosmicus and halophilic Halobacter were
found to be the dominant archaea. In the soils of C. triphyllum and C. balansae Saccharomycetales
were detected, while Cryptococcus neoformans var. grubii H99 was exclusively detected in C.
balansae soil. Significant difference (p<0.05) was observed in C. variegatum rhizosphere soil in
terms of organic carbon (C%) and carbon mineralization from the other two soil samples. Significant
differences were observed in all three soils in terms of nitrogen content, and the C. triphyllum
rhizosphere soil was significantly different from the others in terms of available phosphorus content
(p<0.05). This study showed that biological as well as the physico-chemical properties of the
rhizosphere soil regulate soil microbial diversity and density and by extension influences their
activity which evidently manifests itself in carbon and nitrogen mineralisation.