水稻不同生育期对硒的吸收、转运及累积规律

采用大田试验,研究土壤施用含硒肥料后水稻中硒的积累和分布的动态变化。结果表明:在水稻不同器官中硒的积累量与含硒肥料施用量呈正相关,相关系数达到0.98以上。水稻成熟期,硒施用量30 kg/hm2和120 kg/hm2处理全株硒浓度分别比对照处理提高了98.9%和313.7%。不同生育期,水稻各个器官中硒含量及累积量不同,水稻硒的生物富集高峰期表现在孕穗期,叶与水稻穗部吸收累积硒有着密切关系。水稻成熟期整个植株中硒的累积量为茎叶精米根颖壳。在整个水稻生育期硒有一定的运转累积规律:水稻分蘖期时,硒从根、茎流向叶片;孕穗期再由叶流向茎;灌浆期又从根运转到叶和穗中;最后成熟期叶中的硒流向穗。苗期施用含硒肥料是一条提高水稻硒含量的有效农艺措施。

Accumulation and Distribution of Selenium in Rice (Oryza sativa) at Different Growth Stages

To enhance Se accumulation in rice and meet human nutritional needs of Se by daily diet, an experiment was conducted to study the kinetics of accumulation and distribution of Se in rice in a yellow muddy soil treated with nanoscale Se composite fertilizers. The results showed that the studied rice cultivar had a relatively low ability to accumulate Se from the yellow muddy soil, but the uses of Se fertilizers significantly increased Se accumulation in rice, and Se accumulation in rice tissues positively correlated with the Se fertilization rate. A large variation in Se concentration was observed in different rice tissues at different growth stages. The highest Se-bioconcentration was observed at the booting stage, and Se distribution in rice at the maturity stage was in an order of stem > leaf > rice grain > root > husk. Se flow was figured out during rice growth cycle as follows: Se firstly accumulated in leaves from roots and stems at tillering stage, then flowed from leaves to stem at booting stage, moving up from roots to leaves and panicle by stem at grain-filling stage, and finally stored in rice panicle from leaves at maturity stage. The present study will be helpful for Se biofortification on rice.