%0 Research article
%T Relationship between autumn cold hardiness and field performance in northern Pinus sylvestris
%A Persson, Torgny
%A Andersson, Bengt
%A Ericsson, Tore
%D 2010
%J Silva Fennica
%V 44
%N 2
%R doi:10.14214/sf.152
%U https://silvafennica.fi/article/152
%X Results from 3 artificial freezing tests (one-year-old seedlings) and 15  field trials (9- to 21-year old trees) of half-sib offspring from first  generation Scots pine (Pinus sylvestris L.) plus-trees were used to  estimate the amount of additive genetic variance for autumn cold  hardiness and traits assessed in the field, and the genetic correlations  between them. Cold hardiness of individual seedlings was scored  visually, based on the discoloration of their needles after freezing in a  climate chamber. The field traits analyzed were tree vitality, tree  height, spike knot frequency, branch diameter, branch angle, stem  straightness, and susceptibility to infection by the pathogenic fungi  Phacidium infestans L., Gremmeniella abietina (Lagerb.) Morelet,  Melampsora pinitorqua (Braun) Rostr. and Lophodermella sulcigena  (Rostr.) Höhn. Narrow sense individual heritabilities varied between  0.30 and 0.54 for autumn cold hardiness, 0 and 0.18 for tree vitality,  0.07 and 0.41 for tree height, and 0.01 and 0.26 for the remaining  traits. Based on the results of the artificial freeze tests, our  estimates of additive genetic correlations indicate that while early  selection for cold hardiness can improve seedling survival rates in the  field, it may also reduce growth in mild environments. It also has minor  effects on quality traits and attack by common fungal diseases. The  results indicate that artificial freeze testing is an appropriate method  for identifying suitable clones for establishing seed orchards to  supply stock for the reforestation of regions with harsh environments.