水稻籽粒非结构性碳水化合物及充实的氮素调控

The Nitrogen Regulation on the Non-carbohydrate and Grain-plumpness in Rice Grain

为了提高籽粒充实度和改善稻米品质,以籼、粳水稻品种为材料,研究不同氮素穗肥施用量对水稻强、弱势粒中可溶性糖积累和直链淀粉含量的影响,探讨淀粉直/支比与籽粒充实度的关系。结果表明,强、弱势粒中可溶性糖含量随着生育进程均呈"L"型变化趋势,弱势粒明显高于强势粒;不同处理间均随着氮素穗肥施用量的增加,籽粒中可溶性糖含量呈增加趋势,这说明随着施氮量的增加水稻籽粒淀粉合成能力趋于减弱。直链淀粉含量在整个籽粒灌浆期基本呈上升趋势,不同氮素处理间均随着施氮量的增加,直链淀粉含量基本上呈下降趋势,成熟期直链淀粉平均含量表现为籼稻高于粳稻。淀粉直/支比在整个籽粒灌浆期内呈上升趋势,强、弱势粒淀粉直/支比峰值出现的时间不同,表现为弱势粒滞后于强势粒。相关分析表明,强、弱势粒直/支比与其籽粒充实度呈显著或极显著的直线正相关关系,说明提高淀粉直/支比可以提高籽粒充实度。

Under the field condition,two varieties（Indica and Japonica rice） were used to study the effects of panicle nitrogen fertilizer on the accumulation of soluble sugar and amylose content in super-grain and infer-grain of rice in order to increase grain-plumpness and improve rice quality.At the same time,the relationship between the ratio of the amylose content to amylopectin content and the grain plumpness of rice was discussed.The results showed that the change tendency of the soluble sugar was described as＂L＂in superior and inferior grain of rice with the growing stage.The soluble sugar content of the infer-grain was significantly higher than that of the super-grain and increased with the panicle nitrogen rising.In other words,the synthetic ability of the starch was declined with the panicle nitrogen increasing.The amylose content was basically growing in the whole grain-filling stage and decreased with the panicle nitrogen increasing.The average content of amylose in the Indica rice was higher than that of Japonica rice at the mature stage.The ratio of amylose content to amylopectin was increasing during grain-filling stage.However,the appearance time of the peak value of the ratio of amylose content to amylopectin content was different in the superior and inferior grain and most of the infer-grain was lagged behind the super-grain.Correlation analysis showed that the relationship between the ratio of amylose content to amylopectin content and grain plumpness was significant or highly significant linear positively,which indicated that the grain plumpness can be increased with the enhancement of the ratio of amylose content to amylopectin content.