Responses of Chloroplast Light Energy Conversion Characteristic in Rice Seedlings with Different Salt Tolerances to Salt Stress

[Objective] The research aimed to discuss the photosynthetic potentials of photosynthetic organs under salt stress and provide theoretical basis for increasing the photosynthetic capability of the whole plant.[Method] With the seedlings of rice varieties Pokkali(tolerant to salt) and Peta(sensitive to salt) as materials,the responses of chloroplast light energy conversion to salt stress were studied.[Result] The net photosynthetic rate,oxygenevolving activity of chloroplast and ATP content in 2 rice varieties were all decreased with the increasing of concentration and time of NaCl stress.Under the NaCl stress at 100 mmol/L,ATPase activity of chloroplast first increased and then unchanged,and the photophosphorylation activity of chloroplast first increased and then decreased.Under the NaCl stress at 200 mmol/L,ATPase activity and photophosphorylation activity of chloroplast were always decreased and the decreasing degree of salt-tolerant variety Pokkali was obviously smaller than that of salt-sensitive variety Peta.[Conclusion] Chloroplast light energy conversion abilities in salt-tolerant varieties are stronger than that of in salt-sensitive varieties.