不同基因型水稻镉积累动态差异分析

Analysis of Cadmium Accumulation Dynamics in Rice with Distinct Genotypes

为探讨镉（Cd）在籽粒Cd积累量差异较大的2个常规籼型水稻品种‘黄华占’（Cd低积累）和IR68144（Cd高积累）各器官中的分布差异和积累动态,分析了在大田栽培条件下2个品种全生育期和生殖生长期各组织器官的Cd积累动态过程。结果表明：成熟期两品种植株的大部分Cd都集中于根系和茎部,IR68144各器官的Cd含量都高于‘黄华占’。在整个生育期中,‘黄华占’根和茎中的Cd含量都呈缓慢上升趋势,IR68144根系Cd含量先上升后下降,最后于灌浆后期快速上升,其茎部Cd含量则先下降后上升;两品种叶片Cd含量在抽穗前变化趋势表现一直,而在抽穗后却截然相反。抽穗后,‘黄华占’剑叶和穗轴Cd含量先持续上升,后于黄熟期有所下降,而IR68144的剑叶和穗轴都呈持续上升趋势,两品种的颖壳和糙米的Cd含量也都整体上升,且同品种的两器官表现趋于一致。籽粒发育过程中,两品种糙米Cd积累量都不断地提高,但它们超过一半的Cd由抽穗后的第21-28天积累完成。

In order to investigate the cadmium（Cd） dynamic accumulation and distribution in different organsof 2 conventional indica rice varieties‘Huanghuazhan＇（grain Cd low accumulation） and IR68144（grain highCd accumulation）, Cd dynamic accumulation process in the tissues and organs of the two species in wholegrowth period and reproductive stage under field cultivation conditions was studied. The results indicated thatmost Cd of both cultivars was concentrated in the roots and stems at the mature period. Cd contents in differentorgans of IR68144 were higher than that of ‘Huanghuazhan＇. The root and stem Cd contents of‘Huanghuazhan＇were increased slowly in the whole growth period. However, the root Cd content of IR68144 increased firstly and then decreased, and finally rose rapidly at the late grain filling stage. And its stem Cdcontent first decreased and then increased. The leaves Cd contents of the two varieties showed the same trendof change before heading, but got opposite performance after heading. After flowering, flag leaf and rachis Cdcontent of‘Huanghuazhan＇rose continuously, and declined at the stage of yellow ripeness. Nevertheless, flagleaf and rachis Cd content of IR68144 showed an upward tendency constantly. The Cd content of glume andbrown rice of the two varieties rose roughly, and the trend of Cd contents of the two organs from the samevarieties was consistent. During the development of rice grain, brown rice Cd accumulation amounts of bothrice varieties were constantly improved, but more than half of the Cd accumulation amounts were finished between the 21 st and 28 th days after heading.