## 3 Results and Discussions
### Microorganisms Related to Verticillium Wilt of Horseradish Roots
acumintatum_ was the only representative of dominants in 2015 (9.75%). Then, _R. solani_ and _I. destructans_ dominated in 2016. In turn, _G. irregulare_ (8.80%) and _E. nigrum_ (8.18%) dominated in the communities of fungi isolated in 2017. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Species of**} & \multicolumn{8}{c}{**Protection Treatments**} \\ \cline{2-9} \multicolumn{1}{c}{**Fungi**} & \multicolumn{1}{c}{**ChP**} & \multicolumn{1}{c}{**RChP**} & \multicolumn{1}{c}{**BPPo**} & \multicolumn{1}{c}{**BPPo**} & \multicolumn{1}{c}{**BPPs**} & \multicolumn{1}{c}{**BPEm**} & \multicolumn{1}{c}{**Control**} \\ \hline _A. brassiacae_ & & & & **4.41** & **0.35** & **2.43** & **3.66** & **0.11** \\ \hline _A. alternata_ & & & 2.14 & 4.61 & 1.77 & 0.81 & 0.76 & 4.37 \\ \hline B. _eicarea_ & & & & 0.77 & 1.09 & 0.40 & 3.03 & 1.94 \\ \hline C. _globosum_ & & & & 1.54 & 1.36 & 0.40 & 1.39 & \\ \hline _C. lunata_ & & & 2.14 & 0.77 & 1.91 & 1.62 & **2.14** & 1.29 \\ \hline _C. acattatum_ & & & & 2.88 & 1.77 & 1.21 & 1.89 & 3.07 \\ \hline _E. nigrum_ & & & 3.57 & 0.96 & 8.73 & & **8.17** & 1.94 \\ \hline _F. acumintatum_ & & & **5.71** & **4.87** & 4.37 & 0.81 & 5.67 & **5.37** \\ \hline _F. acunaccum_ & & & 3.57 & 4.41 & 0.95 & & 0.63 & **5.51** \\ \hline _F. culmorum_ & & & 1.43 & 1.34 & 0.95 & & 0.88 & 1.29 \\ \hline _F. equiseit_ & & & 3.57 & 3.26 & **3.14** & **3.64** & **2.65** & **4.21** \\ \hline _F. proliferation_ & & & 2.86 & 3.45 & 3.55 & **4.45** & **4.41** & **3.24** \\ \hline _F. solani_ & & & 1.43 & 1.92 & 2.59 & 1.62 & **4.29** & **3.40** \\ \hline _E. incaratum_ & & & & 0.19 & 1.36 & 1.21 & 3.03 & 2.75 \\ \hline _F. sambucinium_ & & & 3.57 & 1.34 & 1.91 & 1.21 & 0.76 & 1.46 \\ \hline _F. oxysporum_ & & & & 0.95 & 0.81 & **2.14** & 0.49 \\ \hline _I. destructans_ & & & & 8.64 & 6.55 & 3.81 & **8.95** & **3.56** \\ \hline _P. expansum_ & & & 4.29 & 4.03 & 2.86 & 1.62 & 2.52 & 0.49 \\ \hline _P. verntcosum_ & & & 2.14 & 0.58 & 0.41 & 0.81 & 0.38 & \\ \hline _S. sclerotorium_ & & & & 2.69 & 3.82 & **4.86** & **2.40** & 0.81 \\ \hline _T. vriate_ & & & & 0.95 & 2.02 & **5.17** & 0.65 \\ \hline _V. dahliae_ & & & & & & & & \\ \hline _R. solani_ & & & & & & & & \\ \hline _Rh. stolonifer_ & & & & & & & \\ \hline _Rhizomucor_ spp. & & & & & & & \\ \hline _Mucor_ spp. & & & & & & & \\ \hline Total fungi & & 84.28 & 88.10 & 92.90 & 90.69 & 91.05 & 90.29 \\ \hline G. _irregulare_ & & & & & & & \\ \hline S & & 19 & 29 & 37 & 32 & 37 & 25 \\ \hline \multirow{2}{*}{Explanations} & \multirow{2}{*}{Eudominants (>10\%)} & \multirow{2}{*}{Eudominants (2.1–5.0%)} & \multirow{2}{*}{Eudominants (5.1–10.0%)} & \multirow{2}{*}{Eudominants (1.1–2.0%)} \\  & & & & & & & & \\ \cline{1-1} \cline{5-5} & & & & & & & \\ \cline{1-1} \cline{5-5} & & & & & & & \\ \cline{1-1} \cline{5-5} & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Frequency of species in microbial communities isolated from horseradish roots. In all protection variants, _V. dahliae_ belonged to the group of endominants, isolated with the highest frequency from the infected roots of the control plot (25.57%) (Table 5, Supplementary Table S2). This proves that the tested preparations limited the development of this species. Its lowest share, at the level of 11.22%, was recorded among isolates obtained from the BPEm combination. The dominant role of _V. dahliae_ in the pathogenesis of Verticillium will is confirmed by other authors [28; 29; 30; 61; 62]. Moreover, in the complex of microorganisms causing Verticillium wilt of horseradish roots progressing from the vascular bundles, the following ranked as dominants: _Globisporangium irregulare_ (_Pythium irregulare_),R. solani, Ilynoncteria destructans (Cylindrocarpon destructans, _Fusarium acuninatumatum_, _Epicocum nigrum_ and _Alternaria brassicae_). There is no information in the literature concerning the share of _I. destructans_ and _G. irregulare_ in the complex causing Verticillium wilt of horseradish roots. Numerous authors point to the high pathogenicity of _I.