Frost Hardiness Development and Lignification of Young Norway Spruce Seedlings of Southern and Northern Finnish origin

1993

S. 47-54

22 Lit. Ang.

Unselbständiges Werk

200040907

Seedlings from four Norway spruce (Picea abies (L.) Karst.) stands originating from areas with effective temperature sums ranging from 710 d.d. to 1150 d.d. were raised under artificial light and temperature treatment. After a 10-week growing period the hardening process was started by subjecting the seedlings to +8 Grad C night temperature and +15 Grad C day temperature, and increasing the night length by 1.5 hour/week. Hardiness was measured by means of artificial freezing treatment (-10 Grad C or -15 Grad C) , followed by visual estimation of the degree of needle injury. The stem height, lignification and bud development were measured before the freezing treatment. The amount of injury increased with increasing southernness of the origin of the tested material. Furthermore, the proportion of non- lignified part of the seedling stem was negatively correlated with the latitude of the provenances. The proportion of seedlings with clearly visible buds was more than 90% in the northernmost entry and less than 1% in the southernmost one. The overall correlation coefficient between the needle injuries and the proportion of non-lignified part of the stem was rather high, but varied considerably from 0.3 in the northernmost material to over 0.6 in the southern provenances. According to the results it seems to be possible to use growth characteristics as an indicator of frost hardiness at the provenance level.