巴西固氮甘蔗品种和广西主栽甘蔗品种氮代谢差异比较

The compararion of Different Nitrogen Metabolism Between Sugarcane Varieties Introduced from Brazil and Cultivate in Guangxi

[目的]探讨从巴西引进的甘蔗品种与广西主栽甘蔗品种在低氮条件下种植的氮代谢差异,以及这种差异与其固氮酶活性之间的关系。[方法]以巴西引进的甘蔗固氮品种和广西主栽的甘蔗品种为材料,在低氮条件下进行桶栽试验,在甘蔗的生长初期、生长盛期及生长后期分别取甘蔗品种的叶片样本分析其氮代谢和铵同化相关的酶活性和固氮酶活性,并分析各指标间的相关性。[结果]不同甘蔗品种的固氮活性不同,其总体表现为巴西引进的甘蔗品种的固氮酶活性都高于当地主栽品种;除了RB72-454品种外,几个巴西品种的硝酸还原酶活性都较高,当地甘蔗品种与巴西引进甘蔗品种的硝态氮含量和谷氨酰胺合成酶活性相差不大;固氮酶活性与几个氮代谢相关指标的相关性分析表明,除了铵态氮含量与固氮酶活性成负相关外,其他几个指标与固氮酶活性都没有太大的相关性,铵态氮对甘蔗体内的固氮酶活性有显著的抑制作用。

[Objective] The research aimed to explore the difference of nitrogen metabolism of different sugarcane varieties introduced from Brazil and cultivate in Guangxi. Meanwhile, the relation of the nitrogenase activity with the difference was analyzed. [Method] The sugarcane varieties introduced from Brazil and cultivate in Guangxi were used as plant materials which were brought up in pots in lower nitrogen level. Several indices correlating to nitrogen metabolism and nitrogenase activity were measured at early stage, flourishing stage and late stage in sugarcane. The relationship among the indices was analyzed. [Result ] The nitrogenase activities in the sugarcane varieties introduced from Brazil were higher as compared to the native ones in general.The sugarcane varieties introduced from Brazil showed higher nitrate reductase activity as compared to the native ones under nitrogen free condition except for the variety RB72-454.There was no obvious difference in the content of NO3^--N and glutamine synthetase activity between the native and Brazilian sugarcane varieties. The correlation analysis showed that the nitrogenase activity in leaves was significantly and negatively correlated with the content of NH4^＋-N, but not with nitrate reductase activity, glutamine synthetase activity and NO3^--N content.