ASSESSMENT OF FLOWERING IN NORWAY SPRUCE (PICEA ABIES) GENOTYPES

Abstract

This article, based on a literature review and research conducted in spring 2025, examines the flowering intensity and formation of generative organs in 9-year-old vegetatively propagated clones of Norway spruce (Picea abies (L.) H. Karst.). The aim of the study was to evaluate variation in the number of male and female flowers among different clones and to determine the number of cones formed in a young breeding archive. The study was carried out in grafted clones established in 2016 at the State Enterprise State Forest Enterprise – Forest tree‘s Breeding Centre (Kaunas district, Lithuania). At the beginning of the 2025 growing season, clear differences in flowering intensity among clones were observed. The number of male flowers ranged from a few to several dozen  per ramet, and some clones showed a mixed flowering type with both male and female flowers. Clones with more intensive male flowering produced higher amounts of pollen. The number of female flowers was lower and more variable among clones, but the first cones were recorded in some clones, indicating an early onset of the generative phase. The results confirm that 9-year-old grafted Norway spruce clones have reached generative maturity, although flowering intensity and sexual structure depend strongly on genotype.