## 2 Materials and Methods
### Genetic Inheritance and Forward Selection
#### 3.3.2. Genetic Gain and Forward Selection  
The genetic gain that could be achieved was estimated at the family level (Table 4) by selecting the best 10% of the families (combinations reported in the majority to mother X). In the Rodna trial, if the best 10% of the families are selected and multiplicated vegetatively, a genetic gain (\(\Delta\)G\({}_{1}\)) of 5.5% (Bd) to 15.3% (Dbh) will be achieved. At the same intensities, if the multiplication takes place sexually, the genetic gains (\(\Delta\)G\({}_{2}\)) range between 3.2% for Bd and 11.8% for Dbh (Table 4).  
In the Palitinis experiment, if the best 10% of the families are selected and multiplicated vegetatively, a genetic gain (\(\Delta\)G\({}_{1}\)) of 3.9% (Bd) to 13.4% (Dbh) will be achieved. At the same intensities, if the multiplication takes place sexually, the genetic gains (\(\Delta\)G\({}_{2}\)) range between 3.5% for Th and Bd and 9.2% for Dbh (Table 4).  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Trials** & \multicolumn{4}{c}{**Palitinis**} & \multicolumn{4}{c}{**Rodna**} \\ \hline
**Parameter/Trait** & **h\({}^{2}\)\({}_{1}\)** & **h\({}^{2}\)\({}_{2}\)** & **\(\Delta\)G\({}_{1}\)** & **\(\Delta\)G\({}_{2}\)** & **h\({}^{2}\)\({}_{1}\)** & **h\({}^{2}\)\({}_{2}\)** & **\(\Delta\)G\({}_{1}\)** & **\(\Delta\)G\({}_{2}\)** \\ \hline Dbh & 0.51 & 0.35 & 13.4 & 9.2 & 0.47 & 0.18 & 15.3 & 11.8 \\ Th & 0.60 & 0.39 & 5.4 & 3.5 & 0.59 & 0.33 & 6.7 & 3.7 \\ Bd & 0.35 & 0.32 & 3.9 & 3.5 & 0.63 & 0.37 & 5.5 & 3.2 \\ Bf & 0.44 & 0.35 & 5.4 & 4.2 & 0.35 & 0.22 & 6.5 & 3.6 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Estimates of heritabilities (h\({}^{2}\)) and genetic gains (\(\Delta\)G%) based on family selection.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Trait–Trait** & **Dbh** & **Th** & **Bd** & **Bf** & **Ss** \\ \hline Dbh & - & 0.52 *** & 0.51 *** & \(-\)0.56 *** & \(-\)0.22 *** \\ Th & 0.75 *** & - & 0.15 * & \(-\)0.43 *** & \(-\)0.26 *** \\ Bd & 0.63 *** & 0.37 *** & - & 0.42 *** & 0.06 \\ Bf & \(-\)0.59 *** & \(-\)0.61 *** & 0.20 *** & - & 0.29 *** \\ Ss & \(-\)0.04 & \(-\)0.13 * & 0.04 & 0.08 & - \\ \hline
**Juvenile–Adult** & **Th\({}_{\text{adult}}\)** & **Th\({}_{\text{juv}}\)** & **Dbh\({}_{\text{adult}}\)** & **Dbh\({}_{\text{juv}}\)** & \\ \hline Th\({}_{\text{adult}}\) & - & 0.42 * & x & 0.44 * & \\ Th\({}_{\text{juv}}\) & 0.72 *** & - & 0.56 ** & x & \\ Dbh\({}_{\text{adult}}\) & x & 0.50 * & - & 0.43 * & \\ Dbh\({}_{\text{juv}}\) & 0.47 * & x & 0.71 *** & - & \\ \hline Dbh, Th, Bd, Bf, and Ss as in Table 1. Th\({}_{\text{adult}}\) and Dbh\({}_{\text{adult}}\) are the current values, while Th\({}_{\text{juv}}\), and Dbh\({}_{\text{juv}}\), are the juvenile values, at the seedling age of 14 years. Significant correlations: * at \(p<\) 0.05, ** at \(p<\) 0.01, and *** at \(p<\) 0.001. & *** at \(p<\) 0.001. & *** at \(p<\) 0.  
Therefore, the best genetic gain will be obtained by the selection of the best 10% of the families (majority with X mother) for Dbh (a situation in which Th will also be improved based on high correlations with Dbh in both trials).