The Genetic Consequences of Mass Selection for Growth Rate on Engelmann Spruce

1989

S. 6-12, 1 Abb.

4 Tab., 46 Lit. Ang., En, Zfsg. En

Unselbständiges Werk

200030103

The genetic consequences of mass selection for growth rate in Engelmann spruce, Picea engelmannii, were studied with 4 enzyme polymorphisms. Super seedlings and their controls were chosen from a nursery and established in two plantings in the Rio Grande National Forest in Colorado. Super seedlings differed from controls in allelic frequencies at 1 of the 4 loci, and at one of the plantings, super seedlings had a higher proportion of highly heterozygous genotypes. The mass section may have favored highly heterozygous genotypes, but the genetic consequences of this selection were slight. Selection has been reported to produce excesses of heterozygotes in the mature stands of several species of conifers. The excesses in heterozygotes are relevant to both the controversy concerning the form of selection in conifers, and the question of the utility of protein genotypes in artificial breeding programs.