© 2001 Heron Publishing—Victoria, Canada
Fast, nondestructive measurement of frost hardiness in conifer seedlings by VIS+NIR spectroscopy
Lars-Göran Sundblad (1), Mikael Andersson (1), Paul Geladi (2), Ann Salomonson (3) and Michael Sjöström (2)
1. Forestry Research Institute of Sweden, Box 3, SE-918 21 Sävar, Sweden / 2. Research Group for Chemometrics, Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden / 3. Annova Research Consultant, Box 7978, SE-907 19 Umeå, Sweden / Received April 10, 2000
Summary
Frost hardiness development from mid-August to mid-November was evaluated in seedlings of three provenances of Norway spruce
(Picea abies (L.) Karst.) and three provenances of Scots pine (Pinus sylvestris L.) raised at nurseries in north, central and south Sweden. Measurements of the visible + near infrared (VIS+NIR) spectra
of shoots were made simultaneously with estimates of frost hardiness based on electrolyte leakage following artificial freezing.
Nine physiological variables known to influence frost hardiness were measured throughout the experiment. Multivariate analysis
showed that VIS+NIR spectra explained 69% and 72% of the variation in frost hardiness in Scots pine and Norway spruce, respectively.
Stem lignification, dry weight fraction, and starch, glucose, fructose, galactose, sucrose, raffinose and stachyose concentrations
together explained 80% and 85% of the variation in frost hardiness in Scots pine and Norway spruce, respectively when used
as independent X variables in a partial least squares model. These physiological variables could be related to varying degrees
with variation in the VIS+NIR spectra. We conclude that VIS+NIR spectroscopy provides a rapid nondestructive technique for
measuring frost hardiness in conifer seedlings based on causal relationships between the spectra and the physiology of seedling
frost hardiness.
Keywords:
dry weight fraction, multivariate analysis, Picea abies, Pinus sylvestris, sugars, starch.
