# Nematoidal Properties of Wild Strains of _Pleurotus ostreatus_
## 3 Results
### Toxic Properties of P. ostreatus Strains against H. schachtii--Cysts' Entwining by Hyphae  
The toxic ability of the tested strains against _H. schachtii_ could not be assessed based on the nematode mobility. _H. schachtii_ is a cyst nematode, and its life cycle differs from that of _C. elegans_. The larvae of _H. schachtii_ are typically grouped in cysts, and, usually, they were not mobile in our tests. It was also possible to observe a small number of larvae, which potentially left the interior of the cysts (Supplementary Figures S6 and S7). However, their natural mobility was also slower compared to _C. elegans_, and they seemed to be less sensitive to the toxin produced by the mycelium than _C. elegans_. _P. ostreatus_ worked by entwining cysts of _H. schachtii_ by hypha and then colonizing them. Thus, the experiments with _H. schachtii_ concerned the ability of the _P. ostreatus_ mycelia to entwine cysts of that nematode. Observations were conducted for 48 h, starting 1 h after the placement of the cysts on the mycelium surface. The hyphae's reaction to the presence of cysts was observed shortly after the beginning of the test and it developed during the experiment, reaching a high level of entwinement between 24 and 48 h (Figure 12). After the first hour of the test, the strains did not differ significantly; the next hour of the test showed a minute differentiation among the tested strains, but the significance of the difference was low (Supplementary Table S1). In the end of the experiment, 19 strains, including mother strains Po2 and Po4, reached entwining activity at the level of 3, and according to the variance analysis and comparison of significance by [PERSON]'s test, Po1 36 dix30 showed the highest activity, significantly different from other strains (Supplementary Table S1). However, the cluster analysis by K-means with the designation of three clusters showed that the best activity in first two hours of the test was characteristic for the majority of strains grouped in cluster 1 (Figure 13). The cluster analysis within 5 to 48 h showed that four strains from cluster 3, Po4, Po1 5 dix27, Po2 20 dix21, and Po4 2 dix1, may be considered the best strains in this test (Figure 14). All of them were grouped previously in cluster 1, which confirms the result (Figures 13 and 14, Tables 4 and 5). \begin{table}
\begin{tabular}{c c} \hline
**Elements of Cluster 1** & **Elements of Cluster 2** \\ \hline Po2 15 dix22 & Po1 36 dix32 \\ \hline Po2 14 dix17 & Po1 5 dix30 \\ \hline Po2 20 dix17 & Po1 26 dix27 \\ \hline Po2 20 dix23 & Po1 42 dix27 \\ \hline Po2 15 dix23 & Po1 5 dix27 \\ \hline Po2 14 dix23 & Po1 26 dix32 \\ \hline Po2 26 dix27 & Po1 26 dix30 \\ \hline Po4 3 dix5 & Po1 42 dix32 \\ \hline Po4 2 dix17 & Po1 36 dix30 \\ \hline Po4 3 dix7 & Po1 5 dix32 \\ \hline Po4 1 dix18 & Po2 14 dix21 \\ \hline Po4 3 dix17 & Po2 20 dix21 \\ \hline Po4 1 dix30 & Po2 15 dix17 \\ \hline Po4 2 dix1 & Po4 2 dix5 \\ \hline Po4 1 dix5 & \\ \hline Po4 2 dix6 & \\ \hline \end{tabular}
\end{table} 
Table 3: Elements of individual clusters—nematode _C. elegans_ mobility as a result of toxic properties of mycelia. The properties to entwine nematodes' cysts by hyphae seem to be one of the most important abilities of the tested mycelia. Thus, we decided to consider the strains in cluster 3 (Table 5) as the most promising strains. The other properties of these strains, tested in the current research, in general, were also good. However, the other strains also may be useful in controlling cyst nematodes. Figure 12: Individual strain ability to entwine cysts of _H. schachttii_; SD was added to 48 h measurements. Figure 13: Analysis of cluster averages by K-means, considering entwinement of cysts by tested mycelia developed in 1–2 h.  
Figure 14: Analysis of cluster averages by K-means, considering entwinement of cysts by tested mycelia developed in 5 h, 24 h, and 48 h.