摘要
通过田间试验,在水稻(扬育粳2号)分蘖期及灌浆期追施锌肥,探究不同生育时期及锌肥施用水平对水稻成熟期植株吸收和累积锌特征的影响.结果显示:在两个时期施肥后,水稻成熟期各器官锌含量和植株锌累积量均随施肥量增加而增加,锌在各器官的分配比例也随之改变;施肥处理后,营养器官茎中锌含量最高可达到对照组的4.3倍(分蘖期),而糙米锌含量较对照组最大增幅分别为20.9%(分蘖期)和29.7%(灌浆期);相同锌肥水平下,分蘖期施肥植株锌累积量(最高454μg)均高于灌浆期(最高266.2μg),而锌收获指数(最大0.194)均低于灌浆期施肥(最大0.336).总之,土壤追施锌肥可以显著增加水稻植株锌的累积,并一定程度上提高水稻籽粒中锌的含量和累积量;灌浆期较分蘖期追施锌肥更有利于提高水稻籽粒锌水平,是通过土壤追肥方式提高水稻籽粒锌水平的关键时期.
A field experiment was designed to explore zinc （Zn） accumulation characteristics in mature paddy rice plants （Japonica rice Yang Yu No. 2） after agronomic Zn biofortification. Zn fertilizers were distributed to the paddy field during the tillering and filling stages. Rice plants were harvested and analyzed in the mature stage. The results show that Zn contents in all organs and Zn accumulation per plant increase with the increasing level of fertilization, while Zn distribution vary with different treatments. The highest Zn content in stems is up to （134. 9±20.9）mg · kg-1 , which is 4. 3 times that of the control group （tillering stage）, while Zn contents in brown rice increase by not more than 20.9% and 29.7% for the tillering and filling stage treatments, respectively. Zn accumulation in the tillering stage treatment is significantly higher than that in the filling stage （the maximum accumulation is 454.0μg for the tillering stage and 266.2 μg for the filling stage）. In contrast, Zn harvest index is up to 0. 336 for the filling stage, much higher than that of the tillering stage with a maximum of 0. 194. Zn biofortification through soil-applied Zn fertilizers can not only significantly increase Zn accumulation of the rice plants but also increase Zn content and Zn mass in grains. Compared to the tillering stage, it is more conducive to improve Zn level in rice grains during the filling stage.
基金
国家自然基金(40601088)
江苏省青年自然科学基金(BK2012202)
中科院南京土壤所国家重点实验室开放基金(Y052010020)资助
关键词
田间试验
土壤追肥
农业锌强化
水稻
锌累积
field trials
soil-applied fertilizers
agronomic Zn biofortification
paddy rice
Zn accumulation
