中国农业科学 ›› 2018, Vol. 51 ›› Issue (23): 4424-4433.doi: 10.3864/j.issn.0578-1752.2018.23.003

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

Cd胁迫水培试验下水稻糙米Cd累积的关键生育时期

王倩倩(),贾润语,李虹呈,周航(),杨文弢,辜娇峰,彭佩钦,廖柏寒()   

  1. 中南林业科技大学环境科学与工程学院/稻米品质安全控制湖南省工程实验室,长沙 410004
  • 收稿日期:2018-06-13 接受日期:2018-08-14 出版日期:2018-12-01 发布日期:2018-12-12
  • 基金资助:
    国家重点研发计划(2016YFD0800705);国家自然科学基金(41501344);湖南省重点学科建设项目(2006180);研究生科技创新基金项目(20183022)

Key Growth Stage of Cd Accumulation in Brown Rice Through a Hydroponic Experiment with Cd Stress

WANG QianQian(),JIA RunYu,LI HongCheng,ZHOU Hang(),YANG WenTao,GU JiaoFeng,PENG PeiQin,LIAO BoHan()   

  1. College of Environment Science and Engineering, Central South University of Forestry and Technology/Hunan Engineering Laboratory for Control of Rice Quality and Safety, Changsha 410004
  • Received:2018-06-13 Accepted:2018-08-14 Online:2018-12-01 Published:2018-12-12

摘要:

【目的】探究水稻不同生育时期Cd胁迫对水稻成熟期糙米Cd累积的影响,明确糙米Cd累积关键生育时期,以期适时采取阻控措施降低糙米Cd含量,为水稻安全生产提供理论参考。【方法】以水稻品种湘晚籼13号(晚稻品种)为研究对象,采用水培试验,共设计7个添加外源Cd处理,即CG(全生育时期Cd胁迫,102 d)、TS(分蘖期Cd胁迫,15 d)、JS(拔节期Cd胁迫,15 d)、BS(孕穗期Cd胁迫,21 d)、FS(灌浆期Cd胁迫,18 d)、DS(腊熟期Cd胁迫,15 d)、MS(成熟期Cd胁迫,18 d),以全生育时期无Cd胁迫作为空白对照(CK),每个处理重复3次。各处理外源Cd胁迫浓度相同,均为20 μg·L -1。水培试验于2017年7月23日开始,在湖南省长沙市中南林业科技大学水稻试验基地进行。2017年11月19日,水稻成熟后,整株采集水稻,测定指标为不同生育时期Cd胁迫下水稻农艺性状(株高、分蘖数和各部位生物量)和水稻各部位(根、茎、叶、穗、谷壳和糙米)Cd含量,计算水稻各部位Cd累积量以及不同生育时期Cd累积对成熟期糙米Cd累积的相对贡献率。【结果】不同生育时期Cd胁迫对水稻株高、分蘖数以及各部位生物量没有显著影响。灌浆期Cd胁迫下,水稻成熟期糙米Cd含量最高,为1.05 mg·kg -1,显著高于水稻成熟期(0.57 mg·kg -1)、孕穗期(0.52 mg·kg -1)、腊熟期(0.38 mg·kg -1)、拔节期(0.31 mg·kg -1)和分蘖期(0.17 mg·kg -1)Cd胁迫下糙米Cd含量。各生育时期Cd胁迫下水稻成熟期糙米Cd累积量范围为0.18—1.56 μg/株,糙米Cd累积量大小顺序为:全生育时期Cd胁迫>灌浆期Cd胁迫>成熟期Cd胁迫>孕穗期Cd胁迫>拔节期Cd胁迫>分蘖期Cd胁迫。孕穗期、灌浆期和成熟期是水稻糙米Cd累积的关键生育时期,对成熟期糙米Cd累积相对贡献率分别为19.7%、39.3%和22.6%,而分蘖期、拔节期和腊熟期的Cd累积对成熟期糙米Cd累积相对贡献较小,贡献率分别为2.4%、4.2%和11.9%。除全生育时期Cd胁迫外,水稻根、茎、穗和谷壳Cd含量均在孕穗期和灌浆期Cd胁迫下较高;各生育时期Cd胁迫下,水稻叶Cd含量无显著性差异。孕穗期和灌浆期Cd胁迫下根Cd累积量较高,分别为86.09 μg/株和79.23 μg/株,显著高于其他生育时期Cd胁迫下根Cd累积量(31.55—40.37 μg/株)。与其他生育时期Cd胁迫相比,水稻植株Cd总累积量在孕穗期和灌浆期Cd胁迫下较高,分别为107.13 μg/株和98.35 μg/株,显著高于其他生育时期Cd胁迫下水稻植株Cd总累积量(42.24—52.47 μg/株)。【结论】水稻的孕穗期、灌浆期和成熟期是控制水稻糙米Cd累积的关键时期。在孕穗期和灌浆期Cd胁迫下,水稻成熟期根和糙米累积Cd最多,因此可以在水稻孕穗期和灌浆期施加改良剂阻隔根系吸收Cd或者阻隔根系吸收的Cd向糙米中转运,从而降低水稻糙米中Cd的累积。

关键词: 水稻, 水培试验, Cd胁迫, 生育时期, Cd累积

Abstract:

【Objective】 The objectives of this study were to explore the effects of Cd stress on Cd accumulation in brown rice at different growth stages (tillering stage, jointing stage, booting stage, filling stage, dough stage, and maturing stage) of rice plants, to clear and definite the key growth stages of rice plants for Cd accumulating in brown rice, so as to provide directions of rice safety production by taking suitable measures timely for reducing Cd contents in brown rice. 【Method】 Taking Xiangwanxian 13 (a late rice variety) as the studied plant, a hydroponic experiment with rice plants was conducted with seven treatments of exogenous Cd application, including CG (whole growth stages with Cd stress, 102 d), TS (tilling stage with Cd stress, 15 d), JS (jointing stage with Cd stress, 15 d), BS (booting stage with Cd stress, 21 d), FS (filling stage with Cd stress, 18 d), DS (dough stage with Cd stress, 15 d), and MS (maturing stage with Cd stress, 18 d). All seven treatments were repeated 3 times and another treatment of the whole growth stages without Cd stress as control (CK). Exogenous Cd in each treatment was the same as 20 μg·L -1. The hydroponic experiment started in July 23, 2017, at the rice experiment base of Central South University of Forestry and Technology in Changsha, Hunan province. Agronomic characters (plant height, tiller number, and biomass of rice tissues) and Cd contents in various rice tissues were determined after harvest in November 19, 2017. Cd amounts and the relative contribution rates of Cd accumulation at different growth stages to Cd accumulation in brown rice at maturing stage were calculated. 【Result】 The results showed that exogenous Cd application at different growth stage of rice plants did not affect plant height, tiller number, and biomass of rice tissues. At the filling stage with Cd stress, Cd contents in brown rice was the highest and reached to 1.05 mg·kg -1, which was significantly higher than Cd contents in brown rice with Cd stress at the maturing stage (0.57 mg·kg -1), booting stage (0.52 mg·kg -1), dough stage (0.38 mg·kg -1), jointing stage (0.31 mg·kg -1), and tilling stage (0.17 mg·kg -1). The range of Cd amounts in brown rice with Cd stress at different growth stages were 0.18-1.56 μg/plant, and the sequence of Cd amounts were: whole growth stages with Cd stress>filling stage with Cd stress>maturing stage with Cd stress>booting stage with Cd stress>jointing stage with Cd stress>tilling stage with Cd stress. The booting stage, filling stage and maturing stage of rice plants were the key growth stages for Cd accumulating in brown rice, and the relative contribution rates of Cd accumulating in brown rice at these three growth stages were 19.7%, 39.3%, and 22.6%, respectively. The contributions of Cd stress to Cd accumulating in brown rice were 2.4%, 4.2%, and 11.9% at the tillering, jointing, and dough stage, respectively, which were relatively lower compared with the other three stages. Cd contents in rice roots, stem, ear, and husk at booting stage and filling stage were all higher except the whole growth stages with Cd stress. There was no significant difference in Cd content in rice leaves (P>0.05) at different growth stages with Cd stress. At the tillering stage and filling stage with Cd stress, Cd amounts in rice roots were 86.09 μg/plant and 79.23 μg/plant, respectively, which was significantly higher than those at the other stages of rice plants (31.55-40.37 μg/plant). Compared to the other stages, Cd amounts in rice plants at the booting stage and filling stage with Cd stress were high, reaching 107.13 μg/plant and 98.35 μg/plant, respectively, which was significantly higher than those at the other four stages of rice plants (42.24-52.47 μg/plant). 【Conclusion】 The booting stage, filling stage, and maturing stage of rice plants were the key growth stages for controlling Cd accumulation in brown rice. With Cd stress at the booting stage and filling stage, the Cd accumulation in the root and brown rice at the maturing stage were higher than those other stages. Therefore, the Cd accumulation in brown rice could be reduced by applying soil amendments at the booting stage and filling stage of rice plants to obstruct root absorbing Cd or reducing Cd transportation from rice root to brown rice.

Key words: rice (Oryza sativa L.), hydroponic experiment, Cd stress, growth stage, Cd accumulation