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Start Over Creator Egbert, K. J.

1. The influence of leaf "windows" on Crassulacean acid metabolism in the South African succulent Senecio rowleyanus (Asteraceae)

Creator:
Egbert, K. J. and Martin, C. E.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
CO2 gas exchange, chlorenchyma, and water-storage parenchyma
Language:
Multiple languages
Description:
Net CO2 exchange rate (PN) of shoots and diel fluctuations in titratable acidity of leaves of Senecio rowleyanus were measured to determine whether penetration of radiant energy through leaf "windows" (narrow, translucent strips on the leaf epidermis) resulted in increased CAM. Nocturnal PN and nighttime increases in acidity were compared among plants with windows covered with reflective adhesive tape, transparent adhesive tape (to control for potential effects of the adhesive), and no tape. The windows did not significantly enhance the degree of CAM in S. rowleyanus. and K. J. Egbert, C. E. Martin.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. The influence of leaf windows on the utilization and absorption of radiant energy in seven desert succulents

Creator:
Egbert, K. J. and Martin, C. E.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, Haworthia truncata, Lithops olivacea, Opthalmophyllum longum, Peperomia dolabriformis, Peperomia graveolens, Peperomia pulchella, photoinhibition, photosynthesis, and Senecio rowleyanus
Language:
Multiple languages
Description:
Four fluorescence parameters [Fv/Fm = the intrinsic efficiency of energy conversion via photosystem 2 (PS2); Fv'/Fm'= the efficiency of energy conversion via PS2 in the light; P = fraction of absorbed radiant energy utilized for photosynthesis; and D = fraction of absorbed radiant energy dissipated as heat] were measured on leaves of seven species of succulents having epidermal windows. While the function of leaf windows has reportedly been to increase absorption of radiant energy and, hence, the rate of photosynthesis in these species, recent evidence indicates that this translucent portion of epidermal tissue, lacking chlorophyll, may also result in photoinhibition in these species, especially for those with growth habits aboveground. Species with aboveground and belowground growth habits were compared with their leaf windows covered with reflective tape and with windows unobstructed. Results showed no increase in photoinhibition for these species resulting from the radiant energy penetrating the window tissue. Although the efficiency of the photosynthetic mechanism was not significantly influenced by the additional radiant energy provided by the window for individual species, there were significant differences in the efficiencies of radiant energy capture (Fv'/Fm') and utilization (P) between the two growth habits. Species with an aboveground growth habit were less efficient in radiant energy utilization compared with the species having a belowground growth habit. and K. J. Egbert, C. E. Martin.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public