Prediction of genetic and phenotypic parameters in Turkish red pine

Progeny trials are one of the basic tools used to obtain genetic parameters in applied tree breeding studies. In this study, periodic data (height at ages 4, 8, 12, and 16 and diameter at ages 8, 12, 16, and 21) of 188 open pollinated families in three Turkish red pine progeny trials in the Aegean Region Lower Altitude Improvement Zone (0-400 m) were analyzed. In order to contribute to the effective progress of the Turkish red pine breeding studies in the Aegean Region; it is aimed to (1) reveal the effectiveness of spatial analysis methods in the estimation of genetic variance in experimental fields established in large areas, (2) estimate the optimum selection age needed to shorten the breeding cycle, and (3) reveal the level of genotype-environment interaction to overcome possible genetic gain loss. When the parameters obtained in the spatial model were compared with the traditional model analyses, it was estimated that additive genetic variances increased by 11% and heritability increased by 5% on average. It was observed that the error (residual) variance increased by an average of 9,3%, while the mean of the standard error of heritability decreased by over 55%. Time, heritability, genetic correlations, selection efficiency coefficient per generation, productive seeding age, coefficients of variation and genetic gains were evaluated for early selection age. When these findings are evaluated together for the optimum selection age, the 12th age diameter character (in the 20-30 family selection) and the 8th age height character (in the 20 or less family selection) stand out. In the latent regression, it has been seen that unstable genotypes (families) interact with the environment and cause loss of genetic gain. With the first 30 family selections, it causes the average genetic gain calculated for the 21st age to decrease by approximately 25%, thus decreasing the gains from 15,6 to 11,75.