Genetic variation and breeding of Silver fir in Romania

Abstract

This paper presents the results of the researche carried on in four Silver fir provenance trialsand in one half – sib family trial, at the age of 25. The tested material includes 60 Silver fir prove-nances, 33 Romanian and 27 foreign, from 8 European countries: France (3), Germany (3), Austria(4), Italy (4), Poland (1), Czech Republic (3), Slovakia (4), Bulgaria (5). The experimental trials weresettled on the following forest districts: Sacele (2), Domnesti, Moinesti and Strambu Baiut.The researche focused on assessment of genetic variation for the most important traits, themagnitude of variation and genetic variation pattern, the selection of best provenances and familieswith regard to productivity traits and adaptability. the investigated traits have been the total height,volume / tree, diameter at 1,30m, branches characters, stem straightness and survival rate.Correlations with the main geographical gradients, narrow – sense heritability and expected geneticgain have also been estimated.In all comparative trials the variance analysis has showed a great interpopulational geneticvariability for the majority of studied traits. Genetic variation is both clinal and ecotype and dependson the examined character. The most significant correlations have been found with longitude and lat-itude of the origin.Generally, good performances for growth traits and great stability have been obtained forRomanian provenances and for foreign provenance as follows: 44 – Lepilat (France) and 23 –Rakitovo (Bulgaria). Provenances from Italy and Austria have achived the lowest growth perform-ances.Interpopulational genetic variability is much higher than the intrapopulational one. At -families level significant differences have been obtained only for growth characters, number ofbranches in verticil and survival rate. Heritability coefficent shows a high genetic control for thesetraits and the expected genetic gain suggests that selection at families level and individuals levelwould be rewarding.