TY  - JOUR
TI  - Response of photosynthesis in the leaves of cucumber seedlings to light intensity and $CO _{2-}$ concentration under nitrate stress
AB  - The effects of 2 nitrate levels, 14 (CK) and 140 mmol $L ^{1-}$ (T), on the leaf gas exchange variables of cucumber (Cucumis sativus L. cv. Xintaimici) seedlings grown in hydroponic culture were investigated. Photosynthetic light- and $CO _{2-}$-response curves from CK and T seedlings were determined and used for the analysis of photosynthetic capacity. The results showed that nitrate stress resulted in a significant reduction of net photosynthesis of T seedlings compared with CK. At the same time, the apparent quantum yield, light-saturated net photosynthesis, carboxylation efficiency, and $CO _{2-}$- saturated net photosynthesis in nitrate-stressed cucumbers also decreased significantly with the increase of treatment time. At 12 days, the apparent quantum yield, light-saturated net photosynthesis, carboxylation efficiency, and $CO _{2-}$- saturated net photosynthesis in nitrate-stressed cucumbers were 47%, 60%, 64%, and 54% lower than CK, respectively. The relative effect of stomatal resistance on photosynthesis (S%) in nitrate-stressed cucumber seedlings increased significantly during the first 8 days and returned to the level of CK thereafter. This evidence indicates that not only stomatal but also nonstomatal limitations might be involved in the reduction of net photosynthetic rate in nitrate-stressed seedlings.
AU  - YANG, Xiaoyu
AU  - WANG, Xiufeng
AU  - WEI, Min
PY  - 2010
JO  - Turkish Journal of Botany
VL  - 34
IS  - 4
SN  - 1300-008X
SP  - 303
EP  - 310
DB  - TRDizin
UR  - http://search/yayin/detay/103110
ER  -