不同水稻品种对NO_3^-同化差异的比较

Comparison of nitrate utilization by four different rice (Oryza sativa L.)cultivars

采用水培方法测定了不同形态氮素下 4个品种水稻 (汕优 63、扬稻 6号、泗优 917、农垦 57) 的生长量及其水稻苗期硝酸还原酶活性 (NRA) 和谷氨酰胺合成酶活性 (GSA)。结果表明, 1mmol·L-1 NH+4 培养下, 水稻生长无明显差异, 而 1mmol·L-1 NO-3 培养 28d后, 各品种水稻生长差异显著, 其中, 扬稻 6号生长最优, 农垦 57最差; 籼稻体内的NRA和GSA比粳稻更高, 其中籼稻叶片的NRA比粳稻高出 58 7%, GSA高出 34 6%, 籼稻根系GSA是粳稻根系的 3 2倍, 说明籼稻对NO-3 的吸收利用优于粳稻。

Four rice cultivars were grown in solution culture and their growth and utilization of nitrate(NO - 3)and ammonium(NH + 4)was compared.The results obtained were as follows.All the four rice cultivars,Shanyou 63,Yangdao 6,Siyou 917 and Nongken 57 grew well and produced similar amounts of biomass in 1 mmol·L -1 ammonium as the only N source.In contrast,they behaved differently when supplied with 1 mmol·L -1 NO - 3.Yangdao 6 produced the greatest biomass while Nongken 57 the lowest growth among the four cultivars in 1 mmol·L -1 NO - 3.Indica rice had higher nitrate reductase activity(NRA)and glutamine synthetase activity(GSA)than Japonica rice in 1 mmol·L -1 NO - 3.The leaf NRA and GSA of Indica rice was 58.7% and 34.6% higher than that of Japonica rice,respectively.The root GSA of Indica rice was 3.2 times higher than Japonica rice.All the results suggested that Indica rice had a greater ability to utilize nitrate than Japonica,which is very useful for the further study of differences in NO - 3 utilization from molecular approach.