摘要
通过盆栽和水培试验研究了籼粳杂交稻甬优12(YY-12)、嘉优中科6号(JY-6)和常规粳稻秀水134(XS-134)在常规供氮(M-N)和低氮(L-N)水平下分蘖盛期水稻氮素利用效率差异,并初步探讨相关机理机制。结果表明:YY-12和JY-6在两种供氮水平下氮素吸收效率明显大于XS-134。与XS-134相比,YY-12和JY-6根系干物质累积明显增大,加之根孔隙度(POR)较大,使其根系径向泌氧量(ROL)明显增加,从而很可能造成YY-12和JY-6根际土壤氨氧化菌(AOB)数量和硝化强度明显增加,使YY-12和JY-6根际土壤矿质氮含量明显大于XS134。相关分析表明根际土壤矿质氮含量与水稻氮素吸收效率极显著正相关。因此,YY-12和JY-6氮素吸收效率高很可能与其种植使根际土壤硝化强度增加和有机氮矿化加剧紧密相关。另外,与M-N处理相比,YY-12和YY-6氮素吸收效率在L-N水平下明显增加,而XS-134无明显差异。主要原因为:与M-N相比,YY-12和JY-6在L-N水平下根系干物质累积和POR增加比例均大于XS-134,ROL和根际土壤硝化强度以及根际土壤矿质氮含量下降比例小于XS-134。
Differences and relative mechanisms of nitrogen(N)uptake efficiency between indica-japonica hybrid rice,namely Yongyou 12(YY-12)and Jiayouzhongke 6(JY-6),and conventional japonica rice,namely Xiushui 134(XS-134)were studied at low and middle N levels during tillering stage by pot and hydroponic experiments.The results showed that N uptake efficiency of YY-12 and JY-6 were significantly higher than that of XS-134 at both N levels.YY-12 and JY-6 developed significantly greater amount of root biomass compared with XS-134.Moreover,larger porosity of root(POR)was found in YY-12 and JY-6 which produced larger root radial oxygen loss(ROL),thus,probably resulted in larger amounts of ammonia oxidizing bacteria(AOB),much higher nitrification activities and mineral N concentrations in rhizosphere soils of YY-12 and JY-6.The mineral nitrogen concentration in rhizosphere soil was significantly and positively correlated to N uptake efficiency of rice plant.Therefore,the high N uptake efficiencies of YY-12 and JY-6 might be closely related to the increase of nitrification activity and the intensification of organic N mineralization in rhizosphere soil.In addition,YY-12 and YY-6 showed significant higher N uptake efficiency under low N level compared with that under middle N level while XS-134 had no difference,the probable reasons were that the root biomass accumulation and increased proportions of POR of YY-12 and YY-6 were much higher than XS-134 under low N level compared with middle N level,furthermore,the decreased proportions for ROL,nitrification activity and mineral nitrogen concentration in rhizosphere soil of YY-12 and YY-6 were less than that of XS-134.
作者
陈贵
陈梅
朱静娜
胡文凌
章斐
张红梅
王士磊
施卫明
程旺大
CHEN Gui;CHEN Mei;ZHU Jingna;HU Wenling;ZHANG Fei;ZHANG Hongmei;WANG Shilei;SHI Weiming;CHENG Wangda(Jiaxing Academy of Agricultural Science,Jiaxing,Zhejiang 314016,China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;Jiaxing Ecology and Environment Bureau,Jiaxing,Zhejiang 314000,China)
出处
《土壤》
CAS
CSCD
北大核心
2020年第6期1113-1119,共7页
Soils
基金
国家自然科学基金项目(31572205)
浙江省自然科学基金项目(LY16D050002)
嘉兴市科技计划项目(2018AY11020,2017AZ13025)资助。
