scholarly journals Action Spectra of Photosystems I and II in State 1 and State 2 in Intact Sugar Maple Leaves

1994 ◽  
Vol 104 (4) ◽  
pp. 1209-1214 ◽  
Author(s):  
K. Veeranjaneyulu ◽  
R. M. Leblanc
Keyword(s):  
Sugar Maple ◽  
Action Spectra ◽  
Photosystems I And Ii ◽  
Maple Leaves ◽  
State 1

Contribution of anthocyanins to the antioxidant capacity of juvenile and senescing sugar maple (Acer saccharum) leaves

2007 ◽  
Vol 34 (8) ◽  
pp. 714 ◽  
Author(s):  
Abby K. van den Berg ◽  
Timothy D. Perkins
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Antioxidant Capacity ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Radical Scavenging ◽  
Anthocyanin Content ◽  
Additional Source ◽  
Stable Free Radical ◽  
Maple Leaves

Foliar anthocyanins are hypothesised to provide an additional source of photoprotection from photooxidative stress to the leaves in which they occur through their ability to scavenge excess free radical species. Although demonstrated to significantly enhance the antioxidant status of red morphs of fully expanded leaves of some species, the contribution of anthocyanins to the antioxidant capacity of the juvenile and senescing leaves in which they frequently occur has not been examined. Antioxidant activity of extracts from anthocyanic and non-anthocyanic juvenile and senescing sugar maple (Acer saccharum Marsh.) leaves from similar light environments was assessed using the stable free radical 1,1-diphenyl-2-picryl hydrazyl (DPPH). Anthocyanin content was significantly correlated with antioxidant activity in extracts of anthocyanic juvenile leaves but only weakly correlated in extracts of anthocyanic senescing leaves. In addition, the antioxidant activity of anthocyanic and non-anthocyanic leaves was equal in both juvenile and senescing leaves. Thus, although anthocyanins may contribute to the antioxidant capacity of anthocyanic juvenile and senescing sugar maple leaves, these results are not consistent with the hypothesis that anthocyanins provide an enhancement to the photoprotection available in either leaf type through free radical scavenging. The results suggest anthocyanins may be part of alternative strategies employed by anthocyanic juvenile and senescing maple leaves to achieve similar levels of antioxidant capacity as their non-anthocyanic counterparts to cope with the same set of environmental challenges.

Identification of Thrips (Thysanoptera: Thripidae) Feeding Sites on Sugar Maple Leaves

1991 ◽  
Vol 84 (6) ◽  
pp. 1771-1773 ◽  
Author(s):  
Durland L. Shumway ◽  
David A. J. Teulon ◽  
Thomas E. Kolb
Keyword(s):  
Sugar Maple ◽  
Feeding Sites ◽  
Maple Leaves

Errors in the calculation of evaporation and leaf conductance in steady-state porometry: the importance of accurate measurement of leaf temperature

1990 ◽  
Vol 20 (7) ◽  
pp. 1031-1035 ◽  
Author(s):  
M. T. Tyree ◽  
T. R. Wilmot
Keyword(s):  
Steady State ◽  
Sugar Maple ◽  
Leaf Surface ◽  
Leaf Temperature ◽  
Leaf Conductance ◽  
Crop Species ◽  
Maple Leaves ◽  
Abaxial Leaf Surface ◽  
Evaporative Flux

Leaf temperatures of sugar maple leaves (Acersaccharum Marsh.) were measured over three growth seasons using in situ copper–constantan thermocouples with wire and junction diameters of 70 and 130 μm, respectively. These thermocouples were coated with a thin layer of adhesive and attached to the abaxial leaf surface over a length of 4 to 5 cm of wire. On sunny days leaf temperatures usually rose 5 to 15 °C above the air temperature. When leaf conductances and evaporative flux were measured with a Li-Cor steady-state porometer under the same conditions, similar leaf temperatures were rarely measured by the Li-Cor leaf thermocouple. We argue that the in situ thermocouple is more likely to measure the actual leaf temperature than the Li-Cor thermocouple. Consequently, the values for leaf conductance and evaporative flux computed by the Li-Cor microprocessor can be wrong by as much as a factor of 2. Errors of similar magnitude may apply to other published measurements for forest species but are not as large in many crop species.

Physiological benefits of feeding in the spring by Lymantria dispar caterpillars on red oak and sugar maple leaves: nutrition versus oxidative stress

Chemoecology ◽  
2012 ◽  
Vol 23 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Raymond V. Barbehenn ◽  
Julie Niewiadomski ◽  
Cristina Pecci ◽  
Juha-Pekka Salminen
Keyword(s):  
Oxidative Stress ◽  
Lymantria Dispar ◽  
Sugar Maple ◽  
Red Oak ◽  
Maple Leaves ◽  
Physiological Benefits
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