Genetically based resistance to the white pine weevil in jack pine and eastern white pine.

摘要

White pine weevil (Pissodes strobi Peck) damage was evaluated in one white pine (Pinus strobus L.) and four jack pine (Pinus banksiana Lamb) half-sib family test sites to determine the role of tree genotype in resistance to the weevil. Half-sib family explained a significant proportion of the variation in weevil attack at all sites. Estimates of family (0.16-0.54) and individual (0.09-0.24) heritabilities of jack pine resistance to white pine weevil were moderate. Estimates of family (0.37) and individual (0.22) heritability of resistance of white pine to the weevil were also moderate when the percentage of test trees damaged by the weevil was relatively low, but were insignificant four years later when more than three-quarters of trees were damaged. Significant positive correlations between mean tree height and mean incidence of trees damaged by the weevil were observed for four of seven site-years but relationships were weak, suggesting that any cost, with respect to height growth, to breeding weevil resistant trees may be small.