Chronic mild salinity affects source leaves physiology and productivity parameters of rice plants (Oryza sativa L., cv. Taipei 309)
2013
Wankhade, Shantanu Devidas | Sanz, Amparo
AIM: In rice, the top two leaves are the major carbohydrate source during grain filling. Physiological performance of these leaves under salinity may allow estimate stress-induced yield loss. METHODS: Greenhouse grown rice plants (cv. Taipei 309) were subjected to 10 and 20 mM NaCl stress levels from germination till maturity. Plant development was measured at the flowering stage and yield parameters were quantified after complete ripening of panicles. RESULTS: Gas exchange in the main source leaves were not significantly affected by any of the stress levels. However, growth parameters as well as total metabolizable carbohydrates content, chlorophyll content (CCI), maximal efficiency of PSII photochemistry in dark-adapted state (F ᵥ/F ₘ) and lipid peroxidation were significantly affected. Rice yield, measured as total panicle production, declined to 78 and 21 % of controls in 10 and 20 mM NaCl stress, respectively. Stress-induced yield loss was positively related with the decline in CCI, F ᵥ/F ₘ and K⁺/Na⁺ ratio as well as with the increase in lipid peroxidation and total soluble carbohydrate contents. CONCLUSIONS: Though the stress levels used in this work are below what is considered the minimal critical threshold of toxicity for rice, they induce significant negative effects on plant development and yield, when present along the whole plant life cycle.
显示更多 [+] 显示较少 [-]