Inhibition of photosynthesis by freezing temperatures and high light levels in cold-acclimated seedlings of Scots pine (Pinus sylvestris). - II. Effects on chlorophyll fluorescence at room temperature and 77 K.

1985 ◽  
Vol 65 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Martin Strand ◽  
Gunnar Oquist
Keyword(s):  
Chlorophyll Fluorescence ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Room Temperature ◽  
High Light ◽  
Light Levels ◽  
Freezing Temperatures

scholarly journals Penconazole Induced Heat Tolerance in Scots Pine (Pinus sylvestris) and Evergreen Oak (Quercus ilex)

2010 ◽  
Vol 36 (5) ◽  
pp. 212-220
Author(s):  
Glynn Percival ◽  
Kelly Noviss
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Electrolyte Leakage ◽  
Quercus Ilex ◽  
Recovery Rates ◽  
Photosynthetic System ◽  
Heat Damage ◽  
Evergreen Oak

The ability of penconazole, a triazole fungicide derivative, to protect against and ameliorate heat stress was studied in evergreen oak (Quercus ilex) and Scots pine (Pinus sylvestris). Under laboratory conditions, heat damage to the leaf photosynthetic system based on the stability of the chlorophyll a/b light-harvesting complex within photosystem II (chlorophyll fluorescence Fo responses) and leaf photochemical efficiency (chlorophyll fluorescence Fv/Fm emissions) of detached leaves was constantly less in penconazole treated trees. In both species, greatest protection of the leaf photosynthetic system to heat induced disorders was achieved by application of penconazole at a concentration of 30 g per liter of water compared to penconazole applied at a concentration of 0.15 or 0.45 g per liter of water. Subjecting containerized trees of both species to 10 minutes at 50°C significantly reduced tree vitality with respect to chlorophyll fluorescence Fo and Fv/ Fm emissions, total foliar chlorophylls, leaf photosynthetic rates (Pn) and significantly increased damage to cellular membrane integrity as manifest by higher leaf electrolyte leakage and visual leaf necrosis between stressed and non-heat stressed well-watered trees. The influence of penconazole applied immediately after heat stress on the pattern of recovery over the following twelve weeks demonstrated penconazole treated trees were the most capable of recovery. With respect to chlorophyll fluorescence Fo and leaf electrolyte leakage values recovery rates of heat damaged trees treated with penconazole ranged from 20%–50% higher than non-triazole treated control trees. In all cases nonpenconazole treated control trees had the least capacity for recovery. Regardless of species, height, leaf area, root, shoot, and total plant dry weight were, in virtually all instances, greater than non-penconazole treated controls. The tactical use of the triazole derivative penconazole as an ameliorant against heat damage and recovery from heat stress in Scots pine and evergreen oak would be of benefit to improve tree recovery rates and growth. From a practical point of view penconazole at 30 g a.i. per liter of water is suggested based on the results of this study.

scholarly journals Anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestris L.) growing in a habitat with varying environmental characteristics

2008 ◽  
Vol 49 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Aljona Lukjanova ◽  
Malle Mandre
Keyword(s):  
Pinus Sylvestris ◽  
Cross Section ◽  
Scots Pine ◽  
Sandy Soil ◽  
Light Exposure ◽  
Anatomical Structure ◽  
High Light ◽  
Soil Mineral ◽  
Environmental Characteristics ◽  
South West

Anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestrisL.) growing in a habitat with varying environmental characteristicsWe investigated the influence of a habitat with varying environmental characteristics on the anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestrisL.). A dune in South-West Estonia was chosen as the study area because it has extreme environmental characteristics: primitive sandy soil, deficiency of water, heavy winds and high light exposure. Analysis showed that the needles of all age and the current-year shoots of pines growing on the foot of the dune had the largest average cross section, mesophyll and parenchyma areas. The degree of the lignification of needles at the foot, on the slope and on the top of the dune differed distinctly. Intensive lignification of the cellular walls of the xylem was observed in needles and shoots of the pines, growing at the foot, but not in the trees growing on the top of the dune. Analysis showed that the anatomical structure and localisation of lignin, both in needles and in shoots, depend on their age, the trees location (foot, slope or top of the dune) and soil mineral composition.

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