57 ORAL SESSION 17 (Abstr. 116-123) Tree Fruit and Berries: Gas Exchange/Photosynthesis
119 ORAL SESSION 31 (Abstr. 597–603) Photosynthesis & Carbon Metabolism–Fruits/Nuts
of the plant circadian clock with the environmental period does influence the net photosynthesis positively ( Dodd et al., 2005 ; Hotta et al., 2007 ). However, supplemental light during the night period might reset the circadian rhythms of the crop
Chambers were constructed to measure gas exchange of entire potted grapevines (Vitis vinifera L.). The plant enclosures were constructed from Mylar film, which is nearly transparent to photosynthetically active radiation. Maintaining a slight, positive, internal pressure allowed the Mylar chambers to inflate like balloons and required no other means of support. The whole-plant, gas-exchange chamber design and construction were simple and inexpensive. They were assembled easily, equilibrated quickly, and did not require cooling. They allowed for the measurement of many plants in a relatively short period. This system would enable the researcher to make replicated comparisons of treatment influences on whole-plant CO2 assimilation throughout the growing season. While CO2 measurement was the focus of this project, it would be possible to measure whole-plant transpiration with this system.
, so as to maintain the higher photosynthesis level of the scion ( Gao et al., 2016 ). Previous research indicated that changes in environmental factors can alter the physiological processes of thylakoid electron transport, carbon reduction, and CO 2
57 ORAL SESSION 17 (Abstr. 116-123) Tree Fruit and Berries: Gas Exchange/Photosynthesis
optimum level of Mn in the medium treatment there is higher electron transport rates, light reactions, and NADPH turnover for the dark reactions, therefore, increased assimilation of CO 2 . Fig. 2. Mean ( A ) leaflet photosynthesis, ( B ) intercellular CO
125 POSTER SESSION 18 Nutrition & Photosynthesis/Vegetable Crops
Based on a commercially available net photosynthesis (Pn) unit coupled to a custom-built chamber that does not require air conditioning, a low-cost system to measure whole-tree gas exchange in the field is described. The temperature in the chamber is influenced by air flow in relation to tree size. A flow of 20 liters·s-1 (equal to ≈1.5 chamber volume changes/min) was sufficient to maintain the leaves of an 11-year-old `Golden Delicious'/M.27 tree at a temperature similar to that of the ambient air and control CO2 gradients in the chamber. The system has been in operation on apple (Malus domestica Borkh.) trees for up to 4 months without modifying tree behavior.
photosynthesis by shading, weakening fruit sink strength resulting from lower light and increased temperature and moisture in the bag, or both. However, little supportive experimental evidence has been provided. Photosynthesis occurs in fruit of many crop plants