Relazioni tra indici di deperimento e variabilità genetica in Picea abies

In different locations of Northern Italian Alps, 197 pairs of Norway spruce [Picea abies (L.) KARST.] plants were sampled. Within each pair, plants showed tolerant (EEC defoliation classes 0 and 1) and to sensitive (defoliation classes 2 and 3) reactions to "new type" damages. This structured sampling produced a random association between genotype and environment. Plants were characterised by 18 isozymatic markers, in order to verify whether the subset of trees with a high level of tolerance is characterised by a different genetic structure compared to sensitive one. Estimates of genetic parameter differed slightly between tolerant and sensitive subsets, suggesting that the tolerance is linked to an overall genetic variability. A logistic regression procedure was used to estimate possible association between multilocus genetic profile of individuai plant and their belonging to tolerant or sensitive classes. Four genetic loci {Lap-B, Pgm-B, Pgi-B and Mnr-B) showed significant contribution, although with a reduced predictive ability.