Genetic Variation in Stone Pine Half-Sib Progenies

--Total height, annual height growth, root collar diameter, total number of branches and total number of buds around the leader bud were recorded at age 6. The experimental material was included 136 half-sib families originating from stone pine natural populations from the Carpathian Mountains. Population samples were included in a randomized complete block experiment with four replications and ten seedlings per family per replication. Highly significant (p<0.001) family variation for all traits was detected. Very high family heritabilities were estimated for total height (hf 2 =0 .968), root collar diameter (hf 2 = 0.938) and total number of branches (hf 2 = 0.966). Genetic correlations between total and annual height growth and root collar diameter were high or very high, ranging between 0.804 and 0.969. These correlations indicated favorable conditions for obtaining substantial genetic gain for a combination of these traits. By selecting the best 30 to 45 families, genetic gains in total height growth and diameter between 28.8 % and 23.4 % and between 18.8 % and 15.3 %, respectively, could be achieved. Suggestions for a breeding strategy are made.