## 3 Results and Discussions
### Microorganisms Related to Verticillium Wilt of Horseradish Roots
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Phylum** & **Genus** & **Species** & \begin{tabular}{c} **Number of** \\ **Isolates** \\ \end{tabular} & \begin{tabular}{c} **Isolation** \\ **Frequency C [\%]** \\ \end{tabular} & \
\begin{tabular}{c} **Group of** \\ **Attendance** \\ \end{tabular} \\ \hline \multirow{6}{*}{_Aspergillus_} & _A. niger_ & [PERSON]. & 14 & 0.40 & SR \\ \cline{2-6}  & _A. terreus_ & [PERSON] & 12 & 0.34 & \\ \cline{2-6}  & _A. brassicae_ &
\begin{tabular}{c} _A. brassicae_ \\ \end{tabular} (Berk.) [PERSON]. & 188 & 5.36 & D \\ \cline{2-6}  & _A. alternata_(Fr.) [PERSON] & 100 & 2.85 & SD \\ \cline{2-6}  & _Botrytis_ & _B. cinerea_ & Pers. & 73 & 2.08 & \\ \cline{2-6}  & _Chaetomium_ & _C. globosum_ & [PERSON]. & 41 & 1.17 & R \\ \cline{2-6}  & _Clonostachys_ & _C. rosea_ & (Link) [PERSON], [PERSON], [PERSON] \& & 10 & 0.28 & SR \\ \cline{2-6}  & _Curvalaria_ & _C. lunata_ & ([PERSON]) [PERSON] & 63 & 1.79 & R \\ \cline{2-6}  & _Colletotrichum_ & _C. acattatum_ & [PERSON] & 86 & 2.45 & SD \\ \cline{2-6}  & _Epicoccum_ & _E. nigrum_ & [PERSON] (2.93) & 195 & 5.56 & D \\ \cline{2-6}  & & _F. acuninatum_ & [PERSON] \& [PERSON]. & 229 & 6.53 & \\ \cline{2-6}  & & _F. avencaeum_ & (Fr.) [PERSON]. & 94 & 2.68 & SD \\ \cline{2-6}  & & _F. culmorum_ & (Wm.G. Sm.) [PERSON]. & 41 & 1.17 & R \\ \cline{2-6}  & & _F. equiseti_ & ([PERSON]) [PERSON]. & 117 & 3.33 & \\ \cline{2-6}  & _F. proliferation_ & ([PERSON].) [PERSON] ex & 139 & 3.96 & SD \\ \cline{2-6}  & & _F. solani_ & (Mart.) [PERSON]. & 114 & 3.25 & \\ \cline{2-6}  & _F. incaratum_ & ([PERSON].) [PERSON]. & 77 & 2.19 & \\ \cline{2-6}  & _F. sambucinum_ & [PERSON] & 51 & 1.45 & \\ \cline{2-6}  & _F. oxysporum_ & [PERSON]. & 39 & 1.11 & R \\ \hline \multirow{2}{*}{_Ilyonectria_} & _I. destructans_ & (Zinssm.) _[PERSON]_, L. & & & \\ \cline{2-6}  & [PERSON] \& [PERSON] & 236 & 6.73 & D \\ \hline \hline \end{tabular}
\end{table} 
Table 4: List of species of microorganisms isolated from horseradish roots affected by Verticillium wilt in the years 2015–2017. Of these, 90.91%, that is 3189 species, were fungi, and 6.87% were _Globisporanguium irregular_ (241 isolates), which was the only representative of Oomycota. The isolated fungi belonged to 34 species and represented 21 genera within the clusters _Ascomycota_, _Basidiumycota_, and _Zygomycota_. At the same time, the 17 genera belonging to _Ascomycota_ accounted for 82.16% of the total isolated fungi. Only one species--_V. dahliae_--was determined as equominant, with a 14.37% share. The group of dominants, constituting a share of 37.80% of the total number of isolated microorganisms, included, in decreasing order (in terms of percentage), _G. irregular_ (6.87%), _R. solani_ (6.75%), _Ibiorcatinkestrans_ (syn. _Cylindarotonkestrans_) (6.73%), _Fusarium acum  
increase in recorded precipitation, the species richness increased to 37 (Table 5, Supplementary Table S2). The same number of species was obtained in the BPPo and BPMe plots. On the other hand, the species richness in the control plot was 25. With full chemical protection (ChP), the S index equalled 19. In the studies to date, there are no reports from research studies that would involve the biodiversity assessment of the community of microorganisms associated with diseases of complex etiology. Earlier studies indicate that with the increasing biodiversity (expressed by various indicators), the severity of disease symptoms decreases [42]. In 2015, the equominant group had the largest share (38.81%), mainly due to the record-high frequency of _V. dahliae_ (28.16%), followed by the 10.65% share of _A. Brassi-ae_(Supplementary Table S1). The _V. dahliae_ species was a constant component of the equominant group in all of the studied years, and in 2016, it was its only representative, accounting for 19.23%. In the last growing season, _R. solani_ (10.90%) and _I. destructans_ (10.16%) also belonged to the group of endominants. On the other hand, the share of the dominant group ranged from 9.75% to 20.88%, and _F.