## 2 Results  
### Contents of Secondary Metabolites in Maturated Hop Cones of Healthy and HVLd-Infected Plants  
Total alpha and beta bitter acids, columulone and colupulone, and xanthohumol contents were determined by HPLC in dry cones of healthy and HLVd-infected plants of the Czech hop cultivars. The infectious status of each sample was checked before the analyses. The results of two harvest years (2019 and 2020) for cultivar Saaz are summarized in Table 1. The content of alpha bitter acids was significantly reduced for both years by 30.6% and 34.2%, respectively, in infected hop plants (Figure 1A). The content of beta bitter acids was not influenced by vivid infection and its variation was due to environmental factors of harvest years. Similar results were obtained for columulone and colupulone, as well as for bitter acids homologues' contents (Table 1). The content of xanthohumol was significantly reduced for both years by 21.7% and 23.5%, respectively, in infected hop plants (Table 1). The results of harvest year 2020 for other cultivars, including Sladek, Premiant, and Agnus, are summarized in Table 2. Identical trends were found for contents of alpha bitter acids and xanthohumol. The content of alpha bitter acids was significantly reduced by 28.2%, 14.8%, and 8.8% in the infected hop plants of the studied cultivars (Figure 1B). The content of xanthohumol was also significantly reduced by 22.9%, 21.1%, and 3.9% in the infected hop plants of the studied cultivars (Table 2). We found a significant increasing of beta bitter acids content (15.9%) and a significant decreasing of columulone content (6.6%) for infected hop plants of cultivar Sladek (Table 2). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**HLVd Infection** & **Negative** & **Positive** & **Negative** & **Positive** \\ \hline
**Harvest year** & **2019** & **2019** & **2020** & **2020** \\
**Number of samples** & **28** & **41** & **14** & **56** \\ \hline Alpha acids (\% of DW) & 5.54 \(\pm\) 0.63 & 3.84 \(\pm\) 0.72 *** & 5.46 \(\pm\) 0.99 & 3.59 \(\pm\) 0.60 *** \\ Beta acids (\% of DW) & 3.78 \(\pm\) 0.32 & 3.96 \(\pm\) 0.47 * & 3.57 \(\pm\) 0.34 & 3.63 \(\pm\) 0.31 \\ Chomulone (\% of AA) & 21.34 \(\pm\) 2.11 & 21.86 \(\pm\) 2.50 & 20.07 \(\pm\) 1.13 & 21.47 \(\pm\) 2.13 ** \\ Colupulone (\% of BA) & 43.07 \(\pm\) 1.92 & 41.45 \(\pm\) 3.07 ** & 38.79 \(\pm\) 0.90 & 39.22 \(\pm\) 2.28 \\ Xanthohumol (\% of DW) & 0.309 \(\pm\) 0.035 & 0.242 \(\pm\) 0.040 *** & 0.289 \(\pm\) 0.032 & 0.221 \(\pm\) 0.034 *** \\ \hline \hline \end{tabular}  
* Probability level: *\(\_\)_p_ \(<\) 0.1, **–\(\_\)_p_ \(<\) 0.05, and ***\(\_\)-\(\_\)_p_ \(<\) 0.01. Abbreviations: DW–dry weight; AA—alpha acids; and BA—beta acids.  
\end{table} 
Table 1: Hop bitter acids and xanthohumol contents (average \(\pm\) SD) in dry cones of HLVd-free and infected plants of the Saaz cultivar. Next, compositions of essential oils (EO) were determined by GC in dry cones of healthy and HLVd-infected plants of Czech hop cultivars. The results of two harvest years (2019 and 2020) for cultivar Saaz are summarized in Table 3. The content of total essential oils was not significantly influenced by vivoid infection. However, significant changes in the composition of essential oils were found. The contents of the studied monoterpenes in EO significantly increased in infected hop plants for both years. Myrcene content was higher by 24.6% and 11.1%, and the increasing \(\alpha\) and \(\beta\)-pinene contents varied by 32.8% to 56.6% in infected hop plants for both years (Table 3). The contents of the individual sesquiterpenes in EO were significantly reduced in a range from 0% to 20% in infected hop plants for both years (Table 3). The contents of terpene alcohols in EO were significantly increased, specifically linalool by 50.7% and 64.4%, as well as geraniol with an increase of 6.2 and 2.5 times in the infected hop plants for both years (Table 3).