## 3 Results and Discussion
### Anti-Rhizoctonia solani Activity of Resorcinolic Lipids  
The results of the poisoned food technique using the resorcinolic lipids isolated from grains of the Kobra cultivar also proved that this group of phenolic lipids markedly limited the development of _R Rhizoctonia solani_ strain F93. Wheat 5-\(n\)-alk(en)ylresorcinols were effective against this fungus, causing 8.93, 17.96, 29.24, 36.82, 43.65, and 52.96 percent inhibition at 75, 100, 125, 150, 175, and 200 \(\mu\)g mL\({}^{-1}\), respectively (Table 4). The ID50 value of 190.34 \(\mu\)g mL\({}^{-1}\) was calculated from a concentration-response curve of this group of compounds. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & & \multicolumn{2}{c}{**Alk(en)ylresorcinol Level [mg kg\({}^{-1}\)] a**} \\ \cline{3-4}
**Plant** & **Cultivar** & **Total ARs in Grains** & **ARs in Chloroform Fraction** \\ \hline \multirow{2}{*}{Winter rye} & Darkowskie & \multirow{2}{*}{588.07 \(\pm\) 2.10 a} & \multirow{2}{*}{9.24 \(\pm\) 0.23 a} \\  & Zlote & & \\ Winter wheat & Kobra & 381.85 \(\pm\) 3.63 b & 4.59 \(\pm\) 0.02 b \\ Spring barley & Rabel & 52.82 \(\pm\) 0.39 c & 3.44 \(\pm\) 0.03 b \\ \hline \hline \end{tabular}  
* Mean values expressing the concentration of alk(en)ylresorcinols \(\pm\) SD were obtained from three independent experiments. Values followed by different letters are significantly different at \(p\) = 0.05 according to [PERSON]/s test; values of each column were analyzed separately.  
\end{table} 
Table 3: The ability of chloroform to remove 5-\(n\)-alk(en)ylresorcinols from the caryopsis surface of various cereals. Figure 2: Percentage composition of 5-\(n\)-alk(en)ylresorcinol homologues of the wheat surface. Mean values expressing the percentage contents of alk(en)ylresorcinols \(\pm\) SD were obtained from three independent experiments. Values followed by different letters are significantly different at \(p\) = 0.05 according to [PERSON]’s test. Significant growth inhibition of rye seedlings by each tested phytopathogenic fungi was observed. In comparison with control plants, the lengths of roots and shoots of rye seedlings grown in the presence of _R. solani_ F93 were shortened by 61.28 and 79.93%, respectively (Table 2). Meanwhile, in the case of _F. culmorum_ F1, 59.61 and 62.83% declines were accordingly noted. However, the removal of the waxy layer from its cryopses did not significantly increase the harmful effects of either of the tested fungi on the development of rye seedlings. Washing off the tiny amount of ARs (1.57%) did not change the high susceptibility of this cereal to either of the tested pathogens (Table 3). The much higher susceptibility of rye, especially to _R. solani_ F93 infection, compared to other cereals was most likely related to the fact that C17:0 was the predominant homologue of its cryopses [3], whereas the C21:0 compound predominated in grains of the remaining tested cereals [12; 13; 14; 17; 18]. Therefore, the more efficient inhibition of _R. solani_ F93 growth (approximately 2.73 times greater) by 200 ug mL\({}^{-1}\) of wheat grain ARs compared to the same dose of resercinolic lipids obtained from rye grains was observed (Tables 4 and 5).However, the addition of the small amount of the C21:0 homologue (6.5 ug mL\({}^{-1}\)) to the natural mixture of rye resercinolic lipids almost doubled the negative effect of these phenolic compounds on the radial growth of _R. solani_ F93 mycelium. Even when the level of rye resercinolic lipids was decreased by 40%, the presence of this homologue in the mixture still significantly improved the inhibition of fungal growth by 6.37% compared to the impact of a natural extract of rye grains without this synthetic compound (Table 5). The results described above led to an experiment in which the action of saturated homologues (C15:0-C23:0) on the growth of _R. solani_ F93 mycelium was estimated. Inhibitory effects of two homologues (C21:0 and C23:0) turned out to be the most potent against this phytopathogen (Figure 3).