PATTERNS OF ADAPTIVE GENETIC-VARIATION IN EASTERN WHITE-PINE (PINUS-STROBUS) FROM QUEBEC

Genetic structure and patterns of genetic variation among provenances for eastern white pine (Pinus strobus L.) in Quebec were examined by a provenance-progeny test. A sample of 66 provenances of eastern white pine from Quebec and adjacent Ontario was tested, with each provenance composed of one to eight separate families (a total of 159 families). Data were collected on total seedling heights at different ages up to 4 years, 4-year branch number, and 3-year bud burst and bud set. Anal ysis of variance showed significant differences in each trait among pr ovenances and among families within provenances, with one exception; V ariance due to provenances was on average twice that due to families w ithin provenances. All traits were intercorrelated at the provenance l evel. Two principal components summarized 77% of the total variation f or all traits. Regressions of different traits on geographical variabl es accounted for 16% to 62% of provenance variation and disclosed comp lex patterns of genetic variation among provenances. Provenances from the southeastern part of the sampling area were taller and burst and s et terminal buds later than the northwestern ones. The regression mode ls were tested using 10-year height and survival from three field test s, which gave mixed results. We used the models describing patterns of provenance variation to guide seed transfer and delineated two provis ional breeding zones for eastern white pine in Quebec.