水稻不同品种在海南富硒土壤中硒的吸收和分配机理

利用盆栽研究了5个水稻品种在两种不同的富硒土壤中Se吸收累积的生育期动态变化和Se在水稻植株不同部位的分配机理.结果表明,随着生长发育期的推进,水稻在孕穗期对Se含量和累积量同时骤增,从苗期到孕穗期水稻Se的累积量占总Se累积量的45.5%～67%,同时Se含量也达到最高,说明这一段时期是水稻吸收Se的关键时期;在富硒土壤1中水稻各器官Se含量都显著大于相应土壤2中水稻各器官,水稻各器官Se含量顺序依次为根>叶>茎>籽粒,Se易向营养体富集;5个水稻品种中只有杂交稻在土壤1中生长正常;3个常规水稻中旱14、2004-95、稻翅品种在土壤2中的SOD、POD酶活性比土壤1中呈明显减小趋势,但杂交稻特优10 SOD酶活性变化相反,其POD酶活性变化的幅度也最小;在土壤2中5个水稻品种生长都正常,杂交稻的平均硒含量最低,但累积量最高.

The absorption and distribution mechanisms of selenium from Hainan selenium-rich soil by different rice varieties

Five rice varieties were chosen to conduct the field experiments and the difference of absorption and accumulation of soil selenium by different rice varieties were studied.The main findings were as follows:The selenium concentrations of different rice varieties in the experiment had significantly correlation with the soil selenium concentrations during the seedling,tillering,grain-fillling and mature stages;The selenium concentrations of different organs(roots,stems,leaves and rices)in the same rice variety in the soils with higher selenium concentrations were higher than the ones in the soils with lower selenium concentrations during different stages;The orders of selenium concentrations of different organs in the same rice variety were:root>leaf>stem>rice,which indicated that the selenium was prone to be accumulated by the nutrient organ;The dynamic changes during the growth stage for the absorption and accumulation of selenium from two different selenium-rich soils by the experiment rice varieties were:with the process of growth stage,the selenium concentrations and accumulation amount of rice were both increased at booting stage,and from seedling stage to booting stage,the rice selenium accumulation amount accounted for 45.5%～67% total selenium accumulation amount and the rice selenium concentration also reached the highest,which suggested that the period from seedling stage to booting stage was the essential period for the selenium absorption by rice;The SOD,POD enzyme activities of Zhonghan 14,2004-95 and Daochi rice varieties in the low selenium soil were significantly decreased compared to the high selenium soil,however,the changes of SOD enzyme activities of Teyou 10 hybrid rice were opposite and its change extent of POD enzyme activities was also the smallest.