Diameter growth and survival of local half-sib families of Scots pine (Pinus sylvestris L.) in Yundola, Bulgaria

Abstract

The paper presents results of a study on a progeny test in Yundola established in 1966 and comprising 26 local plus trees of Scots Pine. Diameters at breast height (DBH) were measured in 1996 and 2012. There were substantial differences among the performance of half-sib families regarding the diameter growth. The best performing families 30 and 46 years after planting were the same, but there were statistically significant changes in the rank of the families as a whole. Mean survival rate was 91% at the age of 30 and 79% at the age of 46, which is relatively high. Individual heritability increased from 0.2 to 0.5-0.6 from the age 30 to 46 and additive genetic coefficient of variation was 5.2% at the age of 30 and 10.1% at the age of 46. Heritabilities and estimated response to selection were within the range of the results reported in other studies on Scots Pine. The main inferences of the study are that individual selection could be a promising tool for genetic improvement of Scots Pine in the region, and genetic parameters could change over time even after 30 years of age.