## 3 Results and Discussion
### HCA, PCA, and Correlation Analysis  
Multivariate statistical tools, including HCA, PCA, and correlation analysis, aid in comprehending the diversity of plant resources and examining the interaction between phenotypic traits [21; 51]. In this study, HCA and PCA were computed using the entire quantitative dataset (Figure 3). The HCA clustered the barley genotypes into eight clusters (Figure 3A). Cluster I had 20 accessions, cluster II had only 4 accessions (including GRA1015, GRA2256, GRA2621, and PI204875), cluster III had 23 accessions, cluster IV had 102 accessions, cluster V had 42 accessions, cluster VI had 39 accessions, cluster VII had 93 accessions, and cluster VIII had 44 accessions. As shown in Figure 4, barley accessions in cluster II were characterized by having the largest average DM (231.25 days), and DH (200.50 days) signifying their late maturing characteristics. In contrast, early-maturing accessions dominated clusters VII and VIII, with an average DM of 209.13 and 209.20 days, respectively. Once again, accessions in cluster II displayed the longest average CL (107.08 cm) and SL (13.56 cm) and the lowest average GPP (19.15), the former two being significantly different from the rest of the clusters and the latter being significantly different from all but clusters I, III, and IV (\(p<0.05\)). Accessions in clusters VII and VIII were characterized by having the highest average GPP (46.19 and 50.54, respectively), each significantly different from the remaining clusters (\(p<0.05\)), but not from the average GPP observed in the control cultivars (32.06). In terms of biochemical traits as well, accessions in cluster II displayed the highest average TPC (4.89 mg GAE/g), DPPH\({}^{\bullet}\) scavenging activity (4.40 mg AAE/g), ABTS\({}^{\bullet+}\) scavenging activity (10.74 mg AAE/100 g), and RP (5.58 mg AAE/g), each being significantly different from the other clusters and also the control cultivars (\(p<0.05\)). Despite this, cluster II displayed the lowest average \(\beta\)-glucan content (0.33 g/100 g). Cluster III had the highest average \(\beta\)-glucan content (4.76 g/100 g) next to the control cultivars (4.85 g/100 g). These values were significantly different from the average \(\beta\)-glucan contents \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Values**} & \multicolumn{2}{c}{**\(\beta\)-GL (g/100 g)**} & \multicolumn{2}{c}{**TPC**} & \multicolumn{2}{c}{**ABTS**} & \multicolumn{2}{c}{**DPPH**} & \multicolumn{2}{c}{**RP**} \\  & \multicolumn{2}{c}{**(mg GAE/g)**} & \multicolumn{2}{c}{**(mg AAE/100 g)**} & \multicolumn{2}{c}{**(mg AAE/g)**} & \multicolumn{2}{c}{**(mg AAE/g)**} \\ \cline{2-10}  & **H** & **NH** & **H** & **NH** & **H** & **NH** & **H** & **NH** & **H** & **NH** \\ \hline Min & 0.14 & 0.43 & 1.79 & 1.88 & 3.27 & 3.07 & 1.56 & 1.57 & 1.63 & 1.31 \\ Max & 7.67 & 6.19 & 6.97 & 6.54 & 13.54 & 7.35 & 6.24 & 3.83 & 7.86 & 3.80 \\ \hline Mean & 3.42 \({}^{\text{b}}\) & 4.24 \({}^{\text{a}}\) & 3.02 \({}^{\text{a}}\) & 2.88 \({}^{\text{b}}\) & 5.57 \({}^{\text{a}}\) & 5.24 \({}^{\text{b}}\) & 2.68 \({}^{\text{a}}\) & 2.57 \({}^{\text{b}}\) & 2.71 \({}^{\text{a}}\) & 2.54 \({}^{\text{b}}\) \\ SD & 1.16 & 0.79 & 0.64 & 0.67 & 1.28 & 0.82 & 0.45 & 0.46 & 0.58 & 0.50 \\ \hline \hline \end{tabular}  
* Different superscript letters in a row within a category indicate significantly different means based on [PERSON]’s multiple range test (\(p<0.05\)). ABTS: ABTS\({}^{\bullet+}\) scavenging activity, DPPH: DPPH\({}^{\bullet}\) scavenging activity, H: Hulled, NH: Hulless, RP: Reducing power, TPC: Total phenolic content, \(\beta\)-GL: \(\beta\)-glucan content.  
\end{table} 
Table 3: Variations of biochemical traits in hulled and hullless barley accessions grown in Korea. found in all other clusters except cluster VI (4.41 g/100 g). Cluster VI was characterized by having significantly lower levels of TPC and antioxidant activities than the other clusters (\(p<0.05\)).