| 水培试验下水稻Pb吸收累积关键生育期 |
| 摘要点击 1270 全文点击 482 投稿时间：2020-02-25 修订日期：2020-03-09 |
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| 中文关键词 生育期 糙米 Pb胁迫 累积 相对贡献率 茎节 |
| 英文关键词 growth stage brown rice Pb stress accumulation relative contribution rate stem node |
| 作者 | 单位 | E-mail | | 胡雨丹 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | 1130985143@qq.com | | 周航 | 中南林业科技大学环境科学与工程学院, 长沙 410004
稻米品质安全控制湖南省工程实验室, 长沙 410004 | zhouhang4607@163.com | | 辜娇峰 | 中南林业科技大学环境科学与工程学院, 长沙 410004
稻米品质安全控制湖南省工程实验室, 长沙 410004 | gujiaofeng@163.com | | 霍洋 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 邓鹏辉 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 魏宾纭 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 刘俊 | 有色金属矿区耕地重金属污染生态阻抗技术研究衡阳市重点实验室, 衡阳 421001 | | | 廖柏寒 | 中南林业科技大学环境科学与工程学院, 长沙 410004
稻米品质安全控制湖南省工程实验室, 长沙 410004 | |
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| 中文摘要 |
| 水稻不同生育期对Pb的吸收累积差异明显.本研究通过水培试验，分别在水稻不同生育期（分蘖期、拔节期、孕穗期、灌浆期、蜡熟期和成熟期）和全生育期添加0.5 mg ·L-1的外源Pb，以全生育期不添加外源Pb作为对照，研究水稻不同生育期Pb吸收累积的影响，明确水稻吸收累积Pb的关键生育时期及对水稻植株和糙米Pb累积的贡献.结果表明：①单一生育期Pb胁迫处理时，水稻株高和分蘖数差异不明显，而全生育期Pb胁迫处理下水稻株高和生物量均受到明显抑制；②水稻成熟后不同部位的Pb含量差异表现为：根系 > 茎节1 > 其他茎节 > 根基茎 > 茎 > 叶 > 穗轴 > 谷壳 > 糙米；不同生育期处理下糙米Pb含量范围为0.1~1.2 mg ·kg-1，其顺序为：孕穗期Pb胁迫 > 拔节期Pb胁迫 > 分蘖期Pb胁迫 > 灌浆期Pb胁迫 > 成熟期Pb胁迫 > 蜡熟期Pb胁迫；③水稻植株Pb累积量相对贡献率在水稻生殖生长时期（灌浆期、蜡熟期和成熟期）较大，而水稻地上部位Pb累积量相对贡献率在水稻营养生长时期（分蘖期、拔节期和孕穗期）较大；④孕穗期是糙米Pb积累的关键生育期，对糙米Pb累积的相对贡献率为43.3%，其次是拔节期和分蘖期处理，相对贡献率分别为24.4%和21.3%；⑤建议在水稻孕穗期适度采用淹水灌溉、施加改良剂或叶面阻控等技术措施，以降低糙米Pb累积，实现Pb污染稻田安全利用. |
| 英文摘要 |
| Pb accumulation in rice varies significantly at different growth stages. In this study, a hydroponic experiment was conducted to study the effects of exogenous Pb stress on Pb accumulation and transportation in rice plants and determine the key rice growth stages of Pb accumulation and their contribution to the Pb content in brown rice. For the hydroponic experiment, 0.5 mg ·L-1 of exogenous Pb was added to rice at different growth stages, including the tillering stage, jointing stage, booting stage, filling stage, dough stage, maturing stage, and whole growth stage (103 d) of the rice plant. Another treatment of the whole growth stage without Pb stress was established as the control. The results showed that: ① There were no significant effects of Pb stress in any single stage on the plant height, tiller number, and biomass, but the rice plant height and biomass significantly decreased under the Pb stress for the whole growth period. ② Pb contents in different tissues at the maturing stage of the rice plant were in the order of root > stem node 1 > other stem nodes > root rhizome > sti > leaf > ear > husk > brown rice. Pb contents in brown rice ranged from 0.1 to 1.2 mg ·kg-1 for all exogenous Pb treatments, and ranked in the growth stages as booting stage > jointing stage > tillering stage > filling stage > maturing stage > dough stage. ③ The relative contribution rates of Pb accumulation in the whole rice plants were relatively high during the reproductive growth period (filling stage, dough stage, and maturing stage), while those in the above-ground parts of the rice plants were relatively high during the vegetative growth stage (tillering stage, jointing stage, booting stage). ④ The booting stage was the key growth period for Pb accumulation in brown rice. Pb stress at this stage contributed 43.3% of Pb content in brown rice, followed by Pb stress at the jointing stage and the tillering stage, with contribution rates of 24.4% and 21.3%, respectively. ⑤ Water management regimes, application of amendments, or leaf resistance control techniques should be applied appropriately at the booting stage of the rice plants to reduce Pb accumulation in brown rice and to realize the safe use of rice paddies polluted with Pb. |
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