Seasonal Variation and Correlation with Environmental Factors of Photosynthesis and Water Use Efficiency of Juglans regia and Ziziphus jujuba

Abstract

Both the photosynthetic light curves and CO(2) curves of Juglans regia L. and Ziziphus jujuba Mill. var. spinosa in three seasons were measured using a LI-6400 portable photosynthesis system. The maximal net photosynthetic rate (A(max)), apparent quantum efficiency(phi), maximal carboxylation rate (V(cmax)) and water use efficiency (WUE) of the two species were calculated based on the curves. The results showed that A(max) of J. regia reached its maximum at the late-season, while the highest values of A(max) of Z. jujuba occurred at the mid-season. The A(max) of J. regia was more affected by relative humidity (RH) of the atmosphere, while that of Z. jujuba was more affected by the air temperature. Light saturation point (LSP) and Light compensation point (LCP) of J. regia had a higher correlation with RH of the atmosphere, those of Z. jujuba, however, had a higher correlation with air temperature. V(cmax) of both J. regia and Z. jujuba had negative correlation with RH of the atmosphere. WUE of J. regia would decrease with the rise of the air temperature while that of Z. jujuba increased. Thus it could be seen that RH, temperature and soil moisture had main effect on photosynthesis and WUE of J. regia and Z. jujuba. Incorporating data on the physiological differences among tree species into forest carbon models will greatly improve our ability to predict alterations to the forest carbon budgets under various environmental scenarios such as global climate change, or with differing species composition.

Changes in Free Amino Acid, Protein, and Flavonoid Content in Jujube (Ziziphus jujube) Fruit during Eight Stages of Growth and Antioxidative and Cancer Cell Inhibitory Effects by Extracts

“…Jujube fruit is an excellent source of flavonoids, but variation in the content of these compounds by maturity, variety, origin from different geographic locations and soil and climate environments, − and postharvest changes , are not well documented. In the present study, we investigated the composition and content in fruits harvested at eight growth stages from the same plant grown under known environmental conditions.…”

Nitrogen physiology of contrasting genotypes of Chenopodium quinoa Willd. (Amaranthaceae)

“…CO 2 compensation point (CCP), used as an estimative of photorespiration 35 , is the [CO 2 ] at which oxygenation proceeds at twice the rate of carboxylation causing photosynthetic uptake of CO 2 to be exactly compensated by photorespiratory CO 2 release. It was estimated from the slope of the CO 2 response curves at the lowest CO 2 concentration 47 .…”

Cytokinin-Dependent Photorespiration and the Protection of Photosynthesis during Water Deficit

“…The G values were obtained from the initial slope of a CO 2 response curve at the lowest CO 2 concentration and could be obtained by fitting the equation and the A/Ci curve (Yang et al, 2008).…”