Stock quality assessment of a somatic interior spruce seedlot

Abstract

Somatic embryogenesis is a form of vegetative propagation that uses tissue culture procedures to rapidly multiply elite genotypes of a selected tree species. Somatic embryogenesis technology still is considered novel by the forest industry for use within forest regeneration programs. In this article, a stock quality testing approach was used to compare a somatic seedlot to comparable zygotic seedlots. The somatic seedlot was comprised of interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex. Engelm.) crosses (PG × PG), white spruce (P. glauca (Moench) Voss) crosses (ENA × ENA), or a mixture thereof (PG × ENA or ENA × PG). This somatic seedlot was compared to zygotic orchard-collected seedlots that shared partial parentage with the somatic seedlot. Seedlings produced from all seedlots were container-grown under standard nursery cultural procedures. Height and rootcollar diameter were measured on all seedlots. Shoot growth potential (i.e., length of new leader elongation) and root growth capacity were measured under controlled environment conditions. Mean height and diameter of the somatic and zygotic seedlots fell within a similar range that met operational grading criteria for a plantable seedling. The somatic and zygotic seedlots also had similar shoot and root growth capability. Comparable stock quality assessment performance between the somatic and zygotic seedlots indicated that somatic embryogenesis is a viable vegetative propagation technology for producing seedlings suitable for reforestation programs. Copyright © 2005 by the Society of American Foresters.