关键词: 烟草、光合特性、叶绿素荧光、低温胁迫, 烟草、光合特性、叶绿素荧光、低温胁迫

Abstract: In order to investigate the cadmium (Cd) dynamic accumulation and distribution in different organs of 2 conventional indica rice varieties ‘Huanghuazhan’ (grain Cd low accumulation) and IR68144 (grain high Cd accumulation), Cd dynamic accumulation process in the tissues and organs of the two species in whole growth period and reproductive stage under field cultivation conditions was studied. The results indicated that most Cd of both cultivars was concentrated in the roots and stems at the mature period. Cd contents in different organs 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 Cd content first decreased and then increased. The leaves Cd contents of the two varieties showed the same trend of change before heading, but got opposite performance after heading. After flowering, flag leaf and rachis Cd content of ‘Huanghuazhan’ rose continuously, and declined at the stage of yellow ripeness. Nevertheless, flag leaf and rachis Cd content of IR68144 showed an upward tendency constantly. The Cd content of glume and brown rice of the two varieties rose roughly, and the trend of Cd contents of the two organs from the same varieties was consistent. During the development of rice grain, brown rice Cd accumulation amounts of both rice varieties were constantly improved, but more than half of the Cd accumulation amounts were finished between the 21st and 28th days after heading.