Genetic and environmental variance in cone size, seed yield, and germination properties of black spruce clones

Abstract

Genetic and environmental variances in cone size, seed yield, and germination properties were evaluated for Piceamariana (Mill.) B.S.P. using material from ramets of 19 clones in a northern Ontario seed orchard. Thirty-seven percent of the variance in cone volume (mean, 2.2 cm 3 ) was accounted for by differences among clones (range, 1.3–3.5 cm 3 ) and 19% was accounted for by ramets within clones. Clone means for number of seed per cone ranged from 49 to 100 and averaged 71; 18% of seed was filled. Clonal variances for number of seed per cone and percent filled seed were 31 and 23% of the total variance, while ramets accounted for 18 and 13%, respectively. Germination of filled seed averaged 68% and clone means ranged from 28 to 90%. Sixty-seven percent of the variation in germination percent was due to clonal differences and 18% was associated with ramets.