Elongation of Scots pine seedlings under blue light depletion

Abstract

The effect of blue light (400-500 nm) removal on the elongation of Scots pine (Pinus sylvetris L.) seedlings was investigated in a field experiment in Northern Finland during two growing seasons. The seedlings were grown in plexiglass chambers and ambient control plots. The blue wavelengths were removed from the light spectrum by using chambers made of orange plexiglass. The results of nearly daily measurements showed that the elongation of Scots pine seedlings was increased by the removal of blue light only at high latitudes.

Blue Mood for Superfood

“…The red to far red ratio (R/FR, 660/730 nm) determines many photomorphogenic and flowering-related responses mediated by phytochrome [3,4]. Blue light has been shown to reduce growth intensity in trees [5][6][7][8] and to inhibit flowering in Cyclamen and Chrysanthemum species [9,10]. In addition, light quality may affect plant productivity, if there is a carbon trade-off between growth and phytochemical accumulation [11][12][13].…”

Competitive success of southern populations of Betula pendula and Sorbus aucuparia under simulated southern climate experiment in the subarctic

“…Mølmann et al (2006) also observed that blue light (B) may delay bud set in any populations of Norway spruce. It is also shown in Scots pine that B may significantly reduce elongation in subarctic experiments (Sarala, Taulavuori, Taulavuori, Karhu, & Laine, 2007;Sarala et al, 2011;Taulavuori et al, 2005). Northern population of Scots pine has shown to be also more sensitive (i.e., benefit more of removal of B) than southern population to B, and removal of B from spectrum has decreased anthocyanin synthesis of many species (Sarala et al, 2011).…”

“…For example, spectral composition may affect elongation of trees and thereby reduce competitive ability for light. Removal of blue light (400–500 nm) from light spectrum has demonstrated that elongation may be regulated through changes in light quality (Sarala, Taulavuori, Karhu, Laine, & Taulavuori, ; Taulavuori et al., ). Blue wavelengths are in essential role in range shift issues, as their relative proportion is high during night and evening hours of polar summer (Taulavuori, Taulavuori, et al., ).…”

Light-driven host-symbiont interactions under hosts’ range shifts caused by global warming: A review

“…It is also proposed that the signal function of annual change in photoperiod is replaced by changes in light quality in the high Arctic (78 N), where midnight sun continues until leaf shedding, and thus cannot provide a signal for growth cessation (Nilsen, 1985). Nilsen (1985) proposed that a reduction in the ratio of red to far-red light (R:FR) may provide an alternative signal, analogous to an increase in blue to red light ratio , in the context of reduced elongation of many species growing in the light of subarctic polar summer (Taulavuori et al, 2005;Sarala et al, 2007Sarala et al, , 2011.…”

“…They may be based on either light exclusion by filtering chambers (e.g. Taulavuori et al, 2005;Sarala et al, 2007Sarala et al, , 2011, or light inclusion by lamp systems . In the latter case, the LEDs (light emitting diodes) provide a variety of possibilities to construct the desired light spectrum.…”