ISHS Acta Horticulturae 165: III International Symposium on Vaccinium Culture
EFFECT OF FOUR LIGHT LEVELS ON NET PHOTOSYNTHESIS AND LEAF ANATOMY OF CRANBERRY (VACCINIUM MACROCARPON AIT.). |
| Authors: | E.J. Stang, B.E. Struckmeyer, D.C. Ferree |
| Abstract:
Rooted cuttings of 'Ben Lear', 'Crowley' and 'Searles' cranberry (V. macrocarpon Ait.) were grown at four light levels simulating levels naturally occurring in the plant canopy in the field. Net photosynthesis (Pn) and transpiration (Tr) were determined on a new shoot per replicate that developed under these light regimes, at 30 and 60 days of treatment. Transverse sections for anatomical examination were prepared for each cultivar and light treatment, following the 60 day Pn determinations. A light response curve was obtained for the 'Searles' cultivar at six light levels ranging from 75–1650 μEM-2S-1. Pn and Tr rates for the three cultivars did not differ at either 30 or 60 days of shading treatment. There were no differences in Pn' or Tr between different light levels' at either sampling date. Maximum Pn (15.0–22.5 mg CO2dm-2hr-1) occurred at approximately 700 μEM-2S-1 light levels in the 'Searles' cultivar and declined to approximately 13.0–15.0 mg CO2dm-2 hr-1 at the highest light intensity (1650 μEM-2S-1). Transverse sections of leaves showed leaf thickness, number of palisade and mesophyll cells was reduced substantially with increased shading. These cellular responses in leaves were most pronounced in 'Searles' followed by 'Ben Lear' and 'Crowley'. | |
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